Engine travel simulation evaluation system

Abstract

[Problem] To improve a characteristic test performed for an engine while a vehicle is traveling. [Solution] This travel simulation evaluation system comprises: a bench device that rotationally drives a dynamo coupled to an engine by a coupling shaft member; and a travel simulator device. The bench device detects the actual shaft torque of the coupling shaft member and the dynamo rotation speed. An inertia correction unit of the travel simulator device subjects the actual shaft torque to an inertia correction in accordance with the amount of variation in the rotation speed of the engine or the dynamo rotation speed, thereby generating an estimated engine torque for the single engine body. A vehicle model unit computes the speed that is based on the rotation speed of a wheel of the vehicle if the vehicle travels at the estimated engine torque. A command rotation speed generation unit changes a command rotation speed in accordance with an operation state that would be achieved if the vehicle travels at the speed, and provides the engine with the rotation speed for a travel simulation.

Description

Engine running simulation evaluation system

[0001] The present invention relates to an engine running simulation evaluation system.

[0002] In vehicles, engines are used as one of the power sources for running, by moving cylinders up and down using pressure generated by combustion to rotate a crankshaft, thereby generating driving force. In vehicles that run on engine driving force, the engine is mounted on the body and actually driven, and measurements are made of exhaust gas and fuel efficiency, whose state quantities change from moment to moment, including the rotation speed under standardized running conditions.

[0003] JP 2017-150954 A JP 2005-308712 A

[0004] In addition to the above-described measurements on an actual vehicle, engine measurements may also be performed using a test bench in which an engine and a dynamo are connected by a connecting shaft, as described in Patent Documents 1 and 2. However, measurements using this test bench are essentially limited to performance tests of the engine alone, such as durability, fuel economy, and exhaust gas, as described in Patent Document 1, or measuring and evaluating the relationship between engine torque and rotation speed as described in Patent Document 2. Conventional engine measurements on test benches cannot measure engine exhaust gas and fuel economy, whose state quantities change from moment to moment, such as rotation speed under standardized driving conditions. Therefore, when measuring engine exhaust gas and fuel economy, whose state quantities change from moment to moment, such as rotation speed under standardized driving conditions, it has been necessary to mount the engine on each vehicle and actually run it, even if a single engine is used in multiple types of vehicles.

[0005] As such, there is room for improvement in the performance testing of engines while the vehicle is running.

[0006] An engine running simulation evaluation system according to one embodiment of the present invention is an engine running simulation evaluation system for evaluating an engine used in a vehicle, and includes: a bench device that connects the engine and a dynamo by a connecting shaft member so that they rotate together, and has a power panel that can rotate and drive the dynamo that rotates together with the engine; and a running simulator device connected to the bench device, wherein the bench device has a torque sensor that detects an actual shaft torque acting on the connecting shaft member, and a rotation speed sensor that detects the rotation speed of the engine and the dynamo rotation speed of the dynamo, and the running simulator device outputs a command rotation speed to the bench device in order to reproduce the same rotation speed as when the engine is mounted on the vehicle in the running simulation. The vehicle has a generation unit, an inertia correction unit that performs inertia correction on the actual shaft torque detected in the bench device in accordance with the amount of fluctuation in the engine rotation speed or the dynamo rotation speed to generate an estimated engine torque for the engine alone, and a vehicle model unit that models the load elements in the vehicle that are driven by the driving force of the engine, wherein the vehicle model unit calculates a speed based on the rotation speed of the vehicle's wheels when the vehicle is running under the estimated engine torque, and the engine rotation speed that changes in accordance with the operating state of the vehicle when the vehicle is running at the wheel rotation speed, and the command rotation speed generation unit outputs the engine rotation speed generated by the vehicle model unit as the command rotation speed to the bench device, and drives the dynamo to rotate at the command rotation speed.

[0007] In the present invention, the above means allows the driving simulation evaluation system to obtain an engine rotation speed profile that is similar to that obtained when the engine is mounted on an actual vehicle and the vehicle is evaluated during driving.

[0008] Moreover, in the present invention, the driving simulator apparatus further includes an inertia correction unit. The inertia correction unit performs inertia correction on the actual shaft torque detected by the bench tester in accordance with fluctuations in engine speed or dynamo speed, thereby generating an estimated engine torque for the engine alone. As a result, the vehicle model unit and command speed generation unit of the present invention can perform their respective processes using the estimated engine torque for the engine alone, which suppresses errors in engine torque due to the engine being connected to the dynamo by a connecting shaft member in the bench tester. It is expected that the engine characteristics measured under the present invention will be as accurate as those measured when the engine is actually mounted on a vehicle and running. Thus, in the present invention, the actual shaft torque detected in real time by the torque sensor is not used directly in the driving simulation, but is instead inertial-corrected by the inertia correction unit. The inertia correction unit performs inertia correction on the actual shaft torque detected in real time by the bench tester in accordance with fluctuations in engine speed or dynamo speed. This makes it possible to obtain a real-time estimated engine torque for the engine. As a result, the present invention can obtain a good and reliable real-time vehicle speed under standardized driving conditions. As a result, the real-time wheel rotation speed of the vehicle in the driving simulation of the present invention, and the real-time vehicle speed based on the wheel rotation speed, can be as reliable as the speed measured when the vehicle is actually driving. Moreover, the present invention does not require the driving simulation evaluation system to measure the torque of the engine alone, for example, by adding an engine cylinder pressure measurement device. The present invention can accurately reproduce the real-time vehicle speed that changes moment by moment under standardized driving conditions in the driving simulation based on the actual axle torque that can be measured in real time using a bench device, and it is possible to measure exhaust gas emissions and fuel efficiency under the driving simulation.

[0009] As a result, in the present invention, the driving simulation evaluation system can reproduce the situation where an engine is mounted on a vehicle and driven, and it becomes possible to accurately measure, for example, the fuel efficiency of the engine under standardized driving. In the present invention, it is possible to test the characteristics of an engine under driving conditions of an automobile without actually mounting the engine on a vehicle and driving it.

[0010] FIG. 1 is a schematic explanatory diagram of an automobile including an engine. FIG. 2 is a configuration diagram of an engine driving simulation evaluation system according to an embodiment of the present invention. FIG. 3 is a configuration diagram of the driving simulator device of FIG. 2. FIG. 4 is a block diagram of functions implemented in the driving simulation evaluation system of FIG. 2. FIG. 5 is an explanatory diagram of the connection state of the engine and dynamo in the bench device of FIG. 2. FIG. 6 is a flowchart of driving simulation control of the driving simulator device of FIG. 4. FIG. 7 is a flowchart of command rotation speed generation control by the command rotation speed generation module of FIG. 4. FIG. 8 is an explanatory diagram of an example of a speed envelope waveform. FIG. 9 is an explanatory diagram showing the accelerator opening generated by the operation model unit using a waveform.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] FIG. 1 is a schematic diagram of an automobile 1 including an engine 7. The automobile 1 is an example of a vehicle. The automobile 1 in FIG. 1 includes an accelerator pedal 3 operated by a driver 19 of the automobile 1, an operation control device 4, a fuel injection control device (EGI) 6, an engine 7, a torque converter 9, a CVT (Continuously Variable Transmission) 10, a drive system including wheels and a vehicle body 11, a TCU (Transmission Control Unit) 12, and a starter motor 13. FIG. 1 also shows running resistance 18.

[0013] The engine 7 generates rotational driving force by moving a cylinder up and down using pressure generated by the combustion of the air-fuel mixture, thereby rotating and driving a crankshaft member 8. In addition to the internal combustion engine 7, the automobile 1 may also have a driving source such as a motor.

[0014] The operation control device 4 generates and outputs an instruction value for the accelerator opening degree corresponding to the amount of operation of the accelerator pedal 3 by the driver 19. The operation control device 4 outputs the instruction value for the accelerator opening degree to the fuel injection control device 6 through a network used in the control system of the automobile 1, such as a CAN BUS 5. The operation control device 4 may be connected to the fuel injection control device 6 through a dedicated line (not shown). In this case, the operation control device 4 outputs the instruction value for the accelerator opening degree to the fuel injection control device 6 through the dedicated line (not shown).

[0015] The fuel injection control device 6 controls the operation of the engine 7, including starting and stopping the engine 7. The fuel injection control device 6 starts the supply of fuel to the engine 7, which is driven by the starter motor 13. This causes the engine 7 to start with an initial explosion and enter an idling state. When a significant non-zero accelerator opening command value is input while the engine 7 is idling, the fuel injection control device 6 controls the amount of air-fuel mixture supplied to the engine 7, etc., so as to obtain an output corresponding to the accelerator opening. As the amount of air-fuel mixture increases, the rotation speed and driving force of the engine 7 increase. As the amount of air-fuel mixture decreases, the rotation speed and driving force of the engine 7 decrease. The driving force of the engine 7 causes the automobile 1 to accelerate and decelerate.

[0016] The torque converter 9 is connected to the crankshaft 8, which is the output shaft of the engine 7. The torque converter 9 is interposed between the engine 7 and the CVT 10, and transmits the driving force of the rotation of the crankshaft 8 of the engine 7 to the CVT 10 by the dynamic action of fluid.

[0017] The CVT 10 increases or decreases, at any rate, the driving force of the rotation of the engine 7 input through the torque converter 9. Note that the automobile 1 may have a gear-switching transmission or the like instead of the CVT 10.

[0018] The drivetrain and vehicle body 11 is the vehicle body and mechanical members provided on the automobile 1 for driving. The drivetrain may be composed of, for example, a propeller shaft, a differential gear, a drive shaft, wheels, and a vehicle body (not shown). The wheels of the vehicle body are in contact with the road surface. The wheels are rotated by the driving force of the engine 7, allowing the automobile 1 to move forward.

[0019] The running resistance 18 is caused by the running of the automobile 1 by the driving force of the engine 7. Rolling resistance (friction resistance) acts on the wheels of the automobile 1. The slip ratio, which is the rate at which the wheels slide against the road surface, varies depending on the friction coefficient between the wheels and the road surface and the wheel load. The running automobile 1 is subjected to air resistance. The running resistance 18 in FIG. 1 schematically represents each of these resistance elements, or the overall resistance element that combines them.

[0020] The TCU 12 is connected to the torque converter 9, the drivetrain and vehicle body 11, the CVT 10, and the fuel injection control device 6. The TCU 12 references control variables such as the accelerator opening and physical variables such as the wheel rotation speed, and outputs instruction signals such as engagement of the lock-up clutch of the torque converter 9 and a target pulley ratio of the CVT 10 to the torque converter 9 and the CVT 10. The TCU 12 also outputs information about the operating state of the CVT 10, such as information about engagement of the lock-up clutch of the torque converter 9, to the fuel injection control device 6 via the CAN bus 5. The fuel injection control device 6 may control the operation of the engine 7 depending on whether the lock-up clutch of the torque converter 9 is engaged.

[0021] The starter motor 13 drives the engine 7 in response to the operation of a start button (not shown) by the driver 19. When the engine 7 reaches an initial combustion speed, such as 250 rpm, the fuel injection control device 6 starts the supply of fuel gas from an injector (not shown) to the engine 7, causing the engine 7 to initially combust. This starts the engine 7. After the engine 7 has initially combusted, the fuel injection control device 6 controls the engine 7 to an idling state. The starter motor 13 may also drive the engine 7 in response to a start command output by the fuel injection control device 6 upon detecting the operation of the start button.

[0022] An automobile 1 having such an internal combustion engine 7 is actually driven with the engine 7 mounted on the automobile 1, and the exhaust gas and fuel economy under standardized driving conditions are measured. The engine 7 is sometimes measured using a test bench in which the engine 7 is connected to a dynamo by a connecting shaft. However, conventional measurements using a test bench are limited to performance tests of the engine itself, such as durability, fuel economy, and exhaust gas, and measurements of the relationship between engine torque and engine speed in a steady state. Conventional engine measurements using a test bench cannot measure the exhaust gas and fuel economy of an engine whose state quantities, such as engine speed, change from moment to moment under standardized driving conditions. Therefore, in the past, in order to measure the exhaust gas and fuel economy of an engine 7 whose state quantities, such as engine speed, change from moment to moment under standardized driving conditions, even when a single engine 7 is used in multiple types of automobiles 1, it was necessary to mount the engine 7 on each automobile 1 and actually drive the engine. As such, there is room for improvement in the evaluation of the engine 7. In this embodiment, the exhaust gas and fuel economy of the engine 7 under standardized driving conditions can be measured on a test bench.

[0023] FIG. 2 is a configuration diagram of a driving simulation evaluation system 20 for an engine 7 according to an embodiment of the present invention. The driving simulation evaluation system 20 for an engine 7 in FIG. 2 is primarily intended to evaluate the engine 7 by measuring exhaust gas and fuel efficiency of the engine 7 under standardized driving conditions. The driving simulation evaluation system 20 for an engine 7 includes only the engine 7 and the fuel injection control device (EGI) 6 of the automobile 1 in FIG. 1 . The fuel injection control device 6 starts the engine 7 by initiating fuel supply to the engine 7 and ignition ignition in a bench device 21, causing initial combustion and starting the engine. Such a driving simulation evaluation system 20 for an engine 7 can evaluate the driving simulation of the engine 7 alone. Note that other components of the automobile 1 may be added to the driving simulation evaluation system 20 for an engine 7. The driving simulation evaluation system 20 for an engine 7 in FIG. 2 includes the bench device 21, a driving simulator device 22, and a CAN controller 23.

[0024] The bench device 21 includes a connecting shaft member 31 , a torque sensor 34 , a dynamo 30 , a power panel 32 of the dynamo 30 , a dynamo encoder 35 , and a bench control device 33 .

[0025] The connecting shaft member 31 connects the crankshaft member 8, which is the output shaft of the engine 7, to the dynamo 30. As a result, the engine 7 and the dynamo 30 are connected to each other so as to rotate together.

[0026] The dynamo 30, together with the connecting shaft member 31, serves as a rotational load for the engine 7. The dynamo 30 may generate rotational driving force under the control of a power panel 32.

[0027] The power board 32 is a power source for the dynamo 30 that drives the dynamo 30 to rotate together with the engine 7 .

[0028] The torque sensor 34 is provided on the connecting shaft member 31. The torque sensor 34 detects the torsional torque acting on the connecting shaft member 31 as an actual shaft torque.

[0029] The dynamo encoder 35 is provided in the dynamo 30. The dynamo encoder 35 serves as a dynamo rotation speed sensor and detects the rotation speed of the dynamo 30 as an actual dynamo rotation speed.

[0030] The bench control device 33 is connected to the fuel injection control device 6, power panel 32, torque sensor 34, and dynamo encoder 35. The bench control device 33 drives the dynamo 30 to rotate via the power panel 32 in accordance with a command rotation speed, which is a command value for the rotation drive of the dynamo 30. The bench control device 33 may control the rotation drive of the dynamo 30, for example, by PID control, which causes the actual dynamo rotation speed to follow the command rotation speed.

[0031] Fig. 3 is a configuration diagram of the driving simulator device 22 of Fig. 2. The driving simulator device 22 of Fig. 3 has a communication port 41, a memory 42, a timer 45, a CPU (Central Processing Unit) 46, and an internal bus 47 to which these are connected.

[0032] The communication port 41 is connected to the CAN controller 23. As shown in FIG. 2, the CAN controller 23 is connected to the fuel injection control device 6 of the bench device 21 and the bench control device 33. The communication port 41 of the driving simulator device 22 transmits and receives information required for controlling the engine 7 between the fuel injection control device 6 of the bench device 21 and the bench control device 33 via the CAN controller 23. For example, the communication port 41 of the driving simulator device 22 outputs information on the operating state of the CVT 10 to the fuel injection control device 6. As a result, the same information as in the case where the fuel injection control device 6 is installed in the automobile 1 of FIG. 1 can be input to the fuel injection control device 6 of FIG. 3. The fuel injection control device 6 of FIG. 3 operates in the same way as in the case where the fuel injection control device 6 is installed in the automobile 1 of FIG. 1, and can control the operation of the engine 7 in the same way as in the case where the fuel injection control device 6 is installed in the automobile 1. Furthermore, the communication port 41 of the driving simulator device 22 outputs a command rotation speed to the bench control device 33. As a result, the bench control device 33 rotates and drives the dynamo 30 at the command rotation speed instructed by the driving simulator device 22.

[0033] The timer 45 measures time and date. The timer 45 may measure the elapsed time from the start of the driving simulation, using the start of the driving simulation as a reference.

[0034] The memory 42 records a program 43 for simulating the running of the engine 7 and data for simulating the running of the engine 7. In Fig. 3, speed envelope data 44 is illustrated as an example of the data recorded in the memory 42.

[0035] The speed envelope data 44 is data that indicates, for example, changes in the vehicle speed of the automobile 1 in a running simulation of the engine 7. The speed envelope data 44 may be data that indicates changes in the vehicle speed of the automobile 1 in a standardized run of the automobile 1. The speed envelope data 44 may be data about a standardized run in order to measure the fuel efficiency of the engine 7, for example. The speed envelope data 44 may be composed of data on a plurality of vehicle speeds for each elapsed time, with the start time of the running simulation as the reference time.

[0036] The CPU 46 reads and executes the program 43 recorded in the memory 42. As a result, the CPU 46 functions as a simulation control unit that controls the operation of the driving simulator device 22.

[0037] FIG. 4 is a block diagram of functions implemented in the driving simulation evaluation system 20 of FIG. 2 . When the CPU 46 of the driving simulator device 22 executes the program 43, the driving simulator device 22 implements the following functions as a simulation control unit: an operation model unit 54, a torque converter model unit 59, a CVT model unit 60, a drivetrain and vehicle body model unit 61, a running resistance model unit 62, a TCU model unit 63, a command rotation speed generation module 55, an inertia correction module 56, and an LPF module unit 57. The torque converter model unit 59, the CVT model unit 60, the drivetrain and vehicle body model unit 61, and the TCU model unit 63 are modeled components of the automobile 1 of FIG. 1 that are not provided in the bench device 21 of FIG. 2 . These components constitute a vehicle model unit 58 that is driven by the driving force of the engine 7 in the automobile 1 and corresponds to the load elements of the engine 7 in the automobile 1. The configuration of the vehicle model unit 58 may vary depending on the automobile 1.

[0038] 4, the fuel injection control device 6 is represented by an EGIECU 51 and an EGI memory 52. ​​The EGI memory 52 stores parameters and programs for controlling the operation of the engine 7, such as initial combustion speed data 53. The EGIECU 51 reads and executes the programs from the EGI memory 52. ​​As a result, the EGIECU 51 functions as a fuel injection control unit of the fuel injection control device 6, which controls the operation of the engine 7, including starting and stopping.

[0039] The operation model unit 54 basically generates an accelerator opening command value based on the speed envelope data 44 recorded in the memory 42 for the driving simulation. The operation model unit 54 may generate the accelerator opening command value, for example, by PID control that feeds back the "vehicle speed" output from the simulation model so that the accelerator opening command value follows the speed envelope data 44. This allows the operation model unit 54 to generate an accelerator opening command value corresponding to the amount of operation of the accelerator pedal 3 by the driver 19 during standardized driving of the automobile 1. The operation model unit 54 outputs the generated accelerator opening command value to the EG-ECU 51 of the fuel injection control device 6 of the bench device 21 via the communication port 41 of the driving simulator device 22, the CAN controller 23, and the bench control device 33. At this time, the bench control device 33 may output the input accelerator opening command value directly to the fuel injection control device 6. As a result, the command value of the accelerator opening can be generated by the operation model unit 54 and then input to the EGIECU 51 of the fuel injection control device 6 without excessive delay. The operation model unit 54, which executes such processing, generates an accelerator opening for the fuel injection control device 6 of the bench device 21 in accordance with the speed envelope data 44 and outputs it to the bench device 21.

[0040] The inertia correction module 56 acquires the actual shaft torque detected by the torque sensor 34 of the bench device 21 via the bench control device 33. The inertia correction module 56 acquires the actual engine speed detected by the engine encoder 36 of the bench device 21 or the actual dynamo speed detected by the dynamo encoder 35 via the bench control device 33. The inertia correction module 56 then performs inertia correction on the actual shaft torque in accordance with the amount of fluctuation in the actual engine speed or the actual dynamo speed. This allows the inertia correction module 56 to generate an estimated engine torque for the engine 7 alone as an inertia correction unit.

[0041] The LPF module unit 57 performs low-pass filtering on the estimated engine torque generated by the inertia correction module 56. The LPF module unit 57 performs low-pass filtering to filter at least torque fluctuations that correspond to the rotation angle of the engine 7. As a result, the estimated engine torque processed by the LPF module unit 57 can have a smooth waveform with torque fluctuations that correspond to the rotation angle of the engine 7 suppressed. The estimated engine torque processed by the LPF module unit 57 is suitable as the torque of the engine 7 alone to be used for driving simulation. Then, the LPF module unit 57, as a low-pass filter unit, outputs the filtered estimated engine torque to a torque converter model unit 59, which is the first model that constitutes a vehicle model unit 58 corresponding to the automobile 1.

[0042] In the vehicle model unit 58, the torque converter model unit 59 models the operation of the torque converter 9 of the automobile 1 in FIG. 1. The torque converter model unit may, for example, model the characteristics of the torque converter 9 of the automobile 1 in terms of the torque ratio or capacity coefficient using mathematical expressions or tables. Such a torque converter model unit 59 can take into account losses in the torque converter 9. The torque converter model unit 59 then processes the estimated engine torque after filtering processing, and outputs the value of the processing result to the CVT model unit 60.

[0043] 1 , and outputs instruction signals such as lock-up clutch engagement by torque converter model unit 59 and target pulley ratio by CVT model unit 60 to the torque converter model unit 59 and CVT model unit 60, respectively, by referencing control variables such as accelerator opening and state variables such as wheel rotation speed. In addition, TCU model unit 63 outputs information on the operating state of CVT model unit 60, such as whether the lock-up clutch is engaged, to the EGIECU 51 of the fuel injection control device 6 of the bench device 21 via the communication port 41 of the driving simulator device 22 and the CAN controller 23. This allows the EGIECU 51 of the fuel injection control device 6 to control the operation of the engine 7 in the driving simulator device 22 in the same way as when the fuel injection control device 6 is provided in the vehicle 1.

[0044] The CVT model unit 60 models the continuously variable transmission function of the CVT 10 of the automobile 1 in FIG. 1 , and performs continuously variable transmission based on instructions from the TCU model unit 63. It is desirable to take into account the energy loss of the CVT 10 and the delay in shifting in response to instructions from the TCU 12 using a table, transfer function, or the like. The CVT model unit 60 then processes the values ​​of the torque converter model unit 59 and outputs the processed values ​​to the driveline and vehicle body model unit 61.

[0045] The drivetrain and vehicle body model unit 61 models the operation of the drivetrain and vehicle body 11 of the automobile 1 in FIG. 1 . The drivetrain and vehicle body model unit 61 may, for example, model the inputs and outputs of the propeller shaft, differential gear, drive shaft, wheels, and vehicle body that make up the drivetrain and vehicle body 11 of the automobile 1 using transfer functions or tables. It is desirable that the transfer functions and tables take into account losses and delays in the drivetrain and vehicle body model unit 61. The drivetrain and vehicle body model unit 61 then processes the values ​​of the CVT model unit 60 and generates the processed values ​​as wheel rotation speeds. The wheel rotation speeds can be accurately converted into the speed and acceleration of the automobile 1.

[0046] The running resistance model unit 62 models the running resistance 18 in Fig. 1 that may occur in the automobile 1 when the automobile 1 is actually driven. The running resistance 18 of the automobile 1 when actually driven includes road resistance, air resistance, etc. The running resistance model unit 62 may model the individual resistances of road resistance and air resistance using mathematical formulas or tables.

[0047] Vehicle model unit 58 simulates the behavior of automobile 1 at the same speed as actual time, and periodically calculates state quantities such as engine speed and vehicle speed using the filtered estimated engine torque as an input. Vehicle model unit 58 is composed of model units for the torque converter, CVT, drivetrain, vehicle body, and running resistance, and reflects specifications such as rotational inertia and tire diameter, as well as the influence of controls such as lock-up commands and CVT pulley ratio commands. Vehicle model unit 58 then outputs the calculated vehicle speed to operation model unit 54, and similarly outputs the calculated engine speed to command speed generation module 55.

[0048] The command rotation speed generation module 55 acquires the engine rotation speed output by the vehicle model unit 58 and outputs it as a dynamo rotation speed command to the bench control device 33. The bench control device 33 uses its internal PID feedback controller to output a dynamo command torque to the power panel 32 so as to follow the dynamo rotation speed command, thereby driving the dynamo 30. In this way, the rotation speed of the engine 7 connected to the dynamo 30 is controlled as if it were installed in an actual vehicle. Furthermore, in the operation model unit 54, the vehicle speed output from the vehicle model unit 58 corresponds to the actual vehicle speed relative to the target vehicle speed input from the speed envelope data 44, and the PID feedback controller of the operation model unit 54 determines the target accelerator opening degree at every moment based on the deviation between the target vehicle speed and the actual vehicle speed. Furthermore, this determined target accelerator opening degree is output to the fuel injection control device 6 of the bench device 21.

[0049] 5 is an explanatory diagram of the connection state of the engine 7 and dynamo 30 in the bench apparatus 21 of FIG. 2. As shown in FIG. 5, the crankshaft member 8 of the engine 7 is connected to the dynamo 30 by the connecting shaft member 31. In the bench apparatus 21, the engine 7 and the dynamo 30 rotate together. The crankshaft member 8 of the engine 7, the connecting shaft member 31, and the dynamo 30 are all rotationally driven by the output torque of the engine 7 and the output torque of the dynamo 30.

[0050] At this time, the torsional torque detected by the torque sensor 34 provided on the connecting shaft member 31 differs from the net output torque of the engine 7 alone due to the influence of the rotational inertia of the engine 7, etc., and therefore, if the above-mentioned actual shaft torque is regarded as the above-mentioned engine net output torque and input to the vehicle model unit 58, the calculation accuracy will be reduced.

[0051] The inertia correction module 56 performs inertia correction on the actual shaft torque Tj detected in real time by the torque sensor 34 using the following equation (1). Here, Je is the rotational inertia of the components closer to the engine than the torque sensor 34. Je may be the combined rotational inertia of the connecting shaft member 31, located closer to the engine than the torque sensor 34, the engine crankshaft 8, and components connected to the crankshaft and rotating together, such as the crank pulley and connecting rod. dω / dt is the fluctuation per unit time of the engine 7 rotation speed, i.e., the rotational angular acceleration of the engine. Furthermore, assuming that resonance is avoided, the dynamo rotation speed can be considered equal to the engine rotation speed, and dω / dt can be substituted for the fluctuation per unit time of the dynamo 30 rotation speed, i.e., the rotational angular acceleration of the dynamo 30. This allows the inertia correction module 56 to generate a real-time estimated engine torque Te for the engine 7 alone. As a result, the vehicle model unit 58 for the driving simulation and the command rotation speed generation module 55 are able to perform their respective processes in real time based on the estimated engine torque, which is the real-time torque of the engine 7 alone.

[0052] Te = Je・dω / dt + Tj...Formula 1

[0053] Next, a driving simulation performed by the driving simulation evaluation system 20 shown in FIG. 4 will be described.

[0054] Fig. 6 is a flowchart of the driving simulation control of the driving simulator device 22 of Fig. 4. The CPU 46 of the driving simulator device 22 functions as a simulation control unit and executes the driving simulation control of Fig. 6. The driving simulation control of Fig. 6 is performed when the driving simulation is executed from a state in which the engine 7 is stopped.

[0055] In step ST11, the CPU 46 determines whether or not to start the driving simulation. If a driving start command is received from the driving simulator device 22, the CPU 46 determines that the driving simulation should be started, and proceeds to step ST12. If a driving start command is not received from the driving simulator device 22, the CPU 46 does not start the driving simulation, and therefore ends this control.

[0056] In step ST12, the CPU 46 sets the time in the timer 45. The CPU 46 sets the timer 45 to an elapsed time measured from the current time being 0.

[0057] Starting in step ST13, the CPU 46 begins processing as the operation model unit 54. The CPU 46 first generates a command value that sets the accelerator opening to 0 and begins outputting the accelerator opening command value. The accelerator opening command value output from the CPU 46 is input to the EGIECU 51 of the fuel injection control device 6 via the communication port 41 of the driving simulator device 22, the CAN controller 23, and the bench control device 33. When the accelerator opening command value is input or updated, the EGIECU 51 of the fuel injection control device 6 controls the operation of the engine 7 so as to output a corresponding value. However, because the engine 7 is stopped at the time of step ST13, the EGIECU 51 does not begin significant control of the operation of the engine 7. The EGIECU 51 simulates the behavior of the starter motor 13 in a real vehicle, and after the dynamo 30 raises the engine 7 rotation speed to or above the cranking rotation speed of the real vehicle, controls the operation of the engine 7 in accordance with the input or updated accelerator opening command value. When generating a command value for setting the accelerator opening to 0 in step ST13, the CPU 46 may generate the command value in the generation process itself in step ST13. Alternatively, a speed of 0 may be recorded at the beginning of the speed envelope data 44 recorded in the memory 42, and the CPU 46 may read this data to generate the command value.

[0058] In step ST14, the CPU 46 determines whether or not the starting of the engine 7 has been completed. The CPU 46 may acquire information on the operating state of the engine 7, for example, from the EGIECU 51 of the fuel injection control device 6. If the engine 7 is idling, for example, the CPU 46 determines that the starting of the engine 7 has been completed, and proceeds to step ST15. On the other hand, if the engine 7 is stopped or not idling, the CPU 46 determines that the starting of the engine 7 has not been completed, and repeats this process. The CPU 46 repeats this process until the starting of the engine 7 is completed.

[0059] In step ST15, the CPU 46 determines whether or not there is an instruction to end the simulation. The CPU 46 determines that there is an instruction to end the simulation based on, for example, an instruction to end the simulation input from a user interface device (not shown). If there is an instruction to end the simulation, the CPU 46 ends this control. On the other hand, if there is no instruction to end the simulation, the CPU 46 proceeds to step ST16.

[0060] In step ST16, the CPU 46 acquires, as the target vehicle speed, data on the vehicle speed corresponding to the current elapsed time measured by the timer 45 from the speed envelope data 44 in the memory 42. Note that when processing step ST16, if the target vehicle speed at the processing timing is not included in the speed envelope data 44, the CPU 46 may obtain the current target vehicle speed by interpolation using the target vehicle speeds at timings before and after that included in the speed envelope data 44.

[0061] In step ST17, the CPU 46 acquires the latest vehicle speed, which is generated every moment by the vehicle model unit 58, as an estimated vehicle speed.

[0062] In step ST18, the CPU 46 generates a command value for the accelerator opening by PID control or the like so that the estimated vehicle speed acquired in step ST17 follows the target vehicle speed acquired in step ST16. The CPU 46 then outputs the generated command value for the accelerator opening to the EGIECU 51 of the fuel injection control device 6. Since the engine 7 has started in step ST15, the EGIECU 51 drives the engine 7 to rotate in accordance with the command value for the accelerator opening that is updated each time step ST18 is processed.

[0063] In step ST19, the CPU 46 determines whether the elapsed time measured by the timer 45 has exceeded the sampling time of the speed envelope data 44 in the memory 42. If the sampling time has not yet passed, the CPU 46 waits until the time has passed. If the time has passed, the CPU 46 acquires a new target vehicle speed for the current time in ST16 and an estimated vehicle speed in ST17, and generates and outputs an accelerator opening in ST18, repeating this process until an instruction to end the simulation is issued. Note that the wait time can also be set to zero by calculating and using the target vehicle speed by interpolating it from the data group of the speed envelope data 44 in synchronization with the calculation cycle of the vehicle model unit 58.

[0064] Through this control, the engine 7 incorporated in the bench device 21 is driven to rotate in a manner that changes from moment to moment in accordance with the speed envelope data 44 for the driving simulation. When the engine 7 is driven, the connecting shaft member 31 and the dynamo 30 are driven to rotate together with the crankshaft member 8 of the engine 7. The torque sensor 34 detects the torsional torque of the connecting shaft member 31 as an actual shaft torque in real time. The dynamo encoder 35 detects the actual rotational speed of the dynamo 30, and the engine encoder 36 detects the actual rotational speed of the engine 7 in real time. The actual shaft torque and the actual dynamo rotational speed or actual engine rotational speed are input to the inertia correction module 56 via the bench control device 33. The inertia correction module 56 performs inertia correction on the actual shaft torque Tj in accordance with the amount of change in the actual engine rotational speed or actual dynamo rotational speed, thereby generating a real-time estimated engine torque for the engine 7 alone.

[0065] The estimated engine torque that has been subjected to low-pass filtering is input to a vehicle model unit 58. Based on the estimated engine torque, the vehicle model unit 58 calculates vehicle state quantities such as engine speed, wheel speed, and vehicle speed, of which the engine speed is acquired by a command speed generation module 55 and output to the bench control device 33 as a dynamo speed command value. The vehicle speed is also output to the operation model unit 54 and used to calculate the accelerator opening. As a result, an accelerator opening command and a dynamo speed command can be generated so that the vehicle speed calculated by the vehicle model unit 58 follows the speed envelope data 44.

[0066] Fig. 7 is a flowchart of the command rotation speed generation control by the command rotation speed generation module 55 of Fig. 4. The CPU 46 of the traveling simulator device 22 executes the command rotation speed generation control of Fig. 7 as the command rotation speed generation module 55. The command rotation speed generation control of Fig. 7 may be started simultaneously with the traveling simulation control of Fig. 6 when the engine 7 is stopped.

[0067] In step ST21, the CPU 46, as the command rotation speed generation module 55, first generates 0 as the command rotation speed for the dynamo 30, which rotates together with the engine 7, and begins outputting the command rotation speed to the power panel 32 of the dynamo 30. The command rotation speed output from the CPU 46 is input to the bench control device 33 via the communication port 41 of the driving simulator device 22 and the CAN controller 23. As a result, the dynamo 30 can be rotated and driven by the power panel 32 under the control of the bench control device 33. However, at the time of step ST21, the dynamo 30 is stopped along with the engine 7. Therefore, the dynamo 30 is not rotated and driven by the power panel 32 under the control of the bench control device 33 at this time. The dynamo 30 begins to be rotated and driven in accordance with the input or updated command rotation speed after the engine 7 begins to start in step ST24, which will be described later. As the dynamo 30 is rotated and driven, the load on the engine 7 can increase or decrease. When generating 0 as the command rotation speed in step ST21, the CPU 46 may generate 0 as the command rotation speed through the generation process in step ST21. Alternatively, a speed of 0 may be recorded at the beginning of the speed envelope data 44 recorded in the memory 42. In this case, the CPU 46 may read the speed data at the beginning of the speed envelope data 44 and generate 0 as the command rotation speed.

[0068] In step ST22, the CPU 46 determines whether it is time to start the engine 7. The CPU 46 may determine that it is time to start the engine 7 when, for example, the elapsed time of the timer 45 reaches a predetermined time. Alternatively, if the speed envelope data 44 recorded in the memory 42 includes data on the timing to start the engine 7, the CPU 46 may determine that it is time to start the engine 7 by reading the start timing data. If it is not time to start the engine 7, the CPU 46 repeats this process. On the other hand, if it is time to start the engine 7, the CPU 46 proceeds to step ST23.

[0069] In step ST23, the CPU 46 executes start motoring control to start the engine 7. The CPU 46 initiates motoring by the dynamo 30 to start the engine 7. In the start motoring control, the CPU 46 basically generates a command rotation speed for driving the dynamo 30 at the same rotation speed as the starter 13 of the automobile 1, instead of the starter 13, and outputs this to the bench control device 33. The bench control device 33 generates a control value, for example, by PID control, so that the actual dynamo rotation speed of the dynamo encoder 35 matches the command rotation speed, and outputs this to the power panel 32. As a result, the dynamo 30 is driven to rotate at the command rotation speed together with the engine 7 connected to the dynamo 30. The EGIECU 51 of the fuel injection control device 6 then monitors the rotation speed of the engine 7. When the EGIECU 51 determines that the engine 7 is rotating at a speed equal to or greater than the initial combustion speed data 53 stored in the EGI memory 52, it begins supplying fuel gas to the engine 7 from an injector (not shown). This causes the engine 7 to start and idle. The initial combustion speed data 53 stored in the EGI memory 52 may be set to the rotational speed at which the starter motor 13 drives the engine 7 in the automobile 1, such as 250 rpm. However, if the engine 7 and the dynamo 30 resonate due to their connection via the connecting shaft member 31, the initial combustion speed should be set to a higher rotational speed, such as 600 rpm. This prevents the engine 7 and the dynamo 30 from resonating when the engine 7 is started. When resonance occurs, the rotational speed vibrations of the engine 7 and the dynamo 30 rapidly increase. Furthermore, in the motoring of the start motoring control, the CPU 46 first simulates cranking of an actual vehicle by a starter motor to increase the rotation speed of the stopped engine 7 to 250 rpm, and then executes control to further increase the rotation speed from 250 rpm to 600 rpm. As a result, the operation of the engine 7 at the time of starting in the driving simulation control can be made to mimic the operation of the engine 7 at the time of starting in the automobile 1.In the start motoring control, the CPU 46 may execute control to increase the rotation speed of the stopped engine 7 from 0 rpm to the initial combustion rotation speed in one go.

[0070] In step ST24, the CPU 46 determines whether the start of the engine 7 has been completed. The CPU 46 acquires information on the operating state of the engine 7 from the EGIECU 51 of the fuel injection control device 6, and may determine that the start of the engine 7 has been completed if the engine 7 is idling. If the start of the engine 7 has not been completed, the CPU 46 repeats this process. The CPU 46 repeats this process until it determines that the start of the engine 7 has been completed. Thereafter, once the start of the engine 7 has been completed, the CPU 46 proceeds to step ST25. Note that if it is clear that the engine 7 will be started by the start motoring control in step ST23, the CPU 46 may proceed to step ST25 immediately after the process of step ST23 without executing this step ST24.

[0071] From step ST25, the CPU 46 starts model control. The CPU 46 acquires the latest engine speed, which is generated by the vehicle model unit 58 every moment.

[0072] In step ST26, the CPU 46 outputs the engine speed acquired from the vehicle model unit 58 as a command speed to the bench control device 33 of the bench device 21. As a result, the dynamo 30 is driven by the drive torque and its speed is controlled so as to follow the dynamo command speed under PID control of the bench control device 33. The engine 7 can reproduce a speed equivalent to that when the engine 7 is mounted on the automobile 1 in the running simulation.

[0073] In step ST27, the CPU 46 determines whether or not to end the running simulation. If the running simulation is not to be ended, the CPU 46 returns the process to step ST25. The CPU 46 repeats the processes from step ST25 to step ST27 until it determines that the running simulation is to be ended. As a result, the CPU 46 basically outputs the command rotation speed, which is generated so as to change moment by moment depending on the stage of the running simulation, to the bench control device 33 of the bench device 21.

[0074] FIG. 8 is an explanatory diagram of an example of a speed envelope waveform. The horizontal axis of FIG. 8 represents the elapsed time from the start of the simulation. The vertical axis represents the target vehicle speed. In FIG. 8, the vehicle speed of the speed envelope starts at 0 km / h, increases from elapsed time t1, and becomes a constant speed from elapsed time t2. Elapsed time t0 is the start timing of the simulation. Elapsed time t4 occurs before elapsed time t1 and is the start timing of the engine 7. Then, motoring begins at the start timing t4 of the engine 7. The speed envelope data 44 recorded in the memory 42 of the driving simulator device 22 includes multiple vehicle speed data for each elapsed time according to this speed envelope waveform.

[0075] FIG. 9 is an explanatory diagram showing the accelerator opening degree as a waveform corresponding to the speed envelope waveform of FIG. 8 . The horizontal axis of FIG. 9 represents the elapsed time from the start of the simulation. The vertical axis represents the accelerator opening degree. The CPU 46 of the driving simulator device 22, functioning as the operation model unit 54, acquires the target vehicle speed at the current elapsed time from the speed envelope data 44 in step ST16 of FIG. 6 . Then, the CPU 46, functioning as the operation model unit 54, generates an instruction value for the accelerator opening degree at each elapsed time in step ST18. As shown in FIG. 9 , the waveform of the instruction value for the accelerator opening degree basically follows the waveform of the speed envelope of FIG. 8 . The instruction value for the accelerator opening degree basically starts from a value of 0, increases at elapsed time t1, and changes to a different value at elapsed time t2. The accelerator opening degree during the acceleration period t1 to t2 is generally larger than that during the subsequent constant speed period t2 onward. However, the waveform of the accelerator opening command value output by the CPU 46 as the operation model unit 54 to the bench control device 33 actually involves slight delays and vibrations due to insufficient command values ​​and control delays, compared to the waveform of Figure 9 that follows the waveform of the speed envelope. The waveform of the accelerator opening command value output to the bench control device 33 changes in accordance with the waveform that follows the speed envelope. However, because the estimated engine torque output from the LPF module unit 57 is used, the waveform of the accelerator opening command value output to the bench control device 33 does not continue to fluctuate finely in accordance with the engine rotation angle.

[0076] As described above, in this embodiment, the traveling simulator device 22 is connected to the bench device 21, which connects the engine 7 and the dynamo 30 via the connecting shaft member 31 so that they rotate together. The CPU 46 of the traveling simulator device 22, as a command rotation speed generation module 55, outputs a command rotation speed to the bench device 21 to provide the engine 7 with a rotation speed for the traveling simulation. Furthermore, the CPU 46 of the traveling simulator device 22, as a vehicle model unit 58 of the automobile 1 driven by the driving force of the engine 7, uses an estimated engine torque and an equation of motion when the automobile 1 is traveling to calculate the rotation speed of the wheels of the automobile 1, the speed based on the rotation speed, and the rotation speed of the engine 7. Here, the vehicle model unit 58 calculates the rotation speed of the engine 7 taking into account the current operating state, such as the acceleration / deceleration ratio at the time of processing. The CPU 46, as a command rotation speed generation module 55, also outputs the rotation speed of the engine 7 as a command rotation speed. This command rotation speed changes depending on the speed at which the automobile 1 is traveling. As a result, in this embodiment, it is possible to measure and evaluate the characteristics of the engine 7, such as fuel efficiency, while the automobile 1 is traveling under a traveling simulation. Furthermore, by providing the vehicle model unit 58 for each of multiple types of automobiles 1 using a single engine 7, it is possible to measure and evaluate the characteristics of the engine 7 when installed in each type of automobile 1. Furthermore, in this embodiment, the traveling simulator device 22 also includes an inertia correction module 56. The inertia correction module 56 performs inertia correction on the actual shaft torque detected in the bench device 21 in accordance with the amount of fluctuation per unit time in the actual dynamo rotational speed, thereby generating an estimated engine torque for the engine 7 alone. As a result, the vehicle model unit 58 and the command rotational speed generation module 55 in this embodiment can perform their respective processes using the estimated engine torque for the engine 7 alone, which suppresses errors in the torque of the engine 7 due to the engine 7 being connected to the dynamo 30 by the connecting shaft member 31 in the bench device 21. The characteristics of the engine 7 measured in this embodiment are expected to be as accurate as those obtained when the engine 7 is actually mounted on the automobile 1 and driven.As a result, in this embodiment, the driving simulation evaluation system 20 can reproduce the situation where the engine 7 is mounted on the automobile 1 and driven, and it becomes possible to accurately measure, for example, the fuel efficiency of the engine 7 during standardized driving.

[0077] In particular, in this embodiment, the actual shaft torque detected in real time by the torque sensor 34 is not directly used in the driving simulation, but is instead inertia-corrected by the inertia correction module 56. The inertia correction module 56 performs real-time inertia correction on the actual shaft torque detected in real time by the bench device 21 in accordance with the fluctuation per unit time of the engine rotation speed or the actual dynamo rotation speed. This enables the present embodiment to obtain a real-time estimated engine torque of the engine 7. As a result, the present embodiment can obtain a good and reliable real-time speed of the automobile 1 under standardized driving conditions. As a result, the real-time wheel rotation speed of the automobile 1 in the driving simulation of this embodiment, and the real-time speed of the automobile 1 based on the wheel rotation speed, can be as reliable as the speed measured when the automobile 1 is actually driven. Furthermore, in this embodiment, there is no need to add, for example, an engine 7 cylinder pressure measurement device to the driving simulation evaluation system 20 to measure the torque of the engine 7 alone. In this embodiment, based on the actual axle torque that can be measured in real time by the bench device 21, the real-time speed of the automobile 1, which changes from moment to moment under standardized driving, can be accurately reproduced in the driving simulation, and exhaust gas and fuel efficiency can be measured under the driving simulation.

[0078] In this embodiment, the inertia correction module 56 performs inertia correction on the real shaft torque Tj based on the above-described Equation 1 to generate an estimated engine torque Te for the engine 7 alone. As a result, the inertia correction module 56 can accurately generate a real-time net torque for the engine 7 alone by eliminating the influence of the rotational inertia of the engine 7 from the real shaft torque Tj detected in real time by the bench device 21. The rotational inertia of the engine 7 includes the equivalent inertia of the connecting shaft member 31 located closer to the engine than the torque sensor 34, the engine crankshaft 8, and the crank pulley and connecting rods coupled to the crankshaft and rotating therewith. Therefore, the vehicle model unit 58 in this embodiment can calculate the wheel rotation speed of the automobile 1 when the automobile 1 is traveling under an estimated engine torque equivalent to the torque of the engine 7 alone. Furthermore, the command rotation speed generation module 55 can accurately obtain a real-time speed when the automobile 1 is traveling based on the wheel rotation speed accurately calculated under an estimated engine torque equivalent to the torque of the engine 7 alone. Furthermore, the command rotation speed generation module 55 can change the command rotation speed so that the rotation speed of the running simulation at that speed is given to the engine 7. As a result, in this embodiment, even though the engine 7 of the automobile 1 is actually connected to the dynamo 30 and the connecting shaft member 31, the running of the automobile 1 according to the running simulation can be well reproduced, thereby increasing the reliability of the running simulation results.

[0079] In this embodiment, the driving simulator device 22 includes an LPF module 57 that filters the estimated engine torque generated by the inertia correction module 56 and outputs the filtered result to the vehicle model 58. The LPF module 57 functions as a low-pass filter to filter torque fluctuations corresponding to the rotation angle of the engine 7. Therefore, the vehicle model 58 of this embodiment can calculate the real-time rotation speed of the wheels of the vehicle 1 when the vehicle 1 is traveling under an estimated engine torque in which torque fluctuations corresponding to the rotation angle of the engine 7, included in the actual axle torque detected by the bench device 21, are suppressed. Furthermore, the command rotation speed generation module 55 can reliably obtain the speed at which the vehicle 1 will travel based on the real-time rotation speed of the wheels that is reliably calculated under the estimated engine torque in which torque fluctuations corresponding to the rotation angle of the engine 7 are suppressed. Furthermore, the command rotation speed generation module 55 can change the command rotation speed so as to provide the engine 7 with the rotation speed of the driving simulation at that speed. In this way, the stability of the driving simulation is improved in this embodiment.

[0080] As a result, in this embodiment, it is possible to measure and evaluate the characteristics of the engine while the automobile 1 is running, without actually mounting the engine 7 on the automobile 1 and running it.

[0081] The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes are possible within the scope of the gist of the invention.

[0082] In the above-described embodiment, the vehicle model unit 58 is composed of a torque converter model unit 59, a CVT model unit 60, a drivetrain and vehicle body model unit 61, a TCU model unit 63, and a running resistance model unit 62. The torque converter model unit 59, the CVT model unit 60, the drivetrain and vehicle body model unit 61, and the TCU model unit 63 individually model each load element driven by the driving force of the engine 7 in the automobile 1. The running resistance model unit 62 models the running resistance 18 of the traveling automobile 1. Alternatively, for example, the vehicle model unit 58 may be configured to combine all of the multiple load elements driven by the driving force of the engine 7 in the automobile 1 into a single model. The running resistance model unit 62 may be incorporated into a part of that combined model. The vehicle model unit 58 may be changed depending on the type of automobile 1 equipped with the engine 7, or may be used commonly for multiple types of automobiles.

[0083] In the above-described embodiment, the timing of the command rotation speed generation control and the driving simulation control is synchronized by determining that the engine 7 has started and is in an idling state. Alternatively, if the command rotation speed generation control and the driving simulation control are synchronized, for example, by simultaneously starting each other, the timing can be synchronized without determining that the engine 7 has started and is in an idling state. In this case, step ST14 can be omitted in the driving simulation control, and step ST24 can be omitted in the command rotation speed generation control. Furthermore, by omitting step ST13, the driving simulation control can execute a driving simulation in which the accelerator pedal 3 is operated from a state in which the engine 7 is stopped. In this case, the command rotation speed generation control may determine in step ST22 that the timing of time t0 in FIG. 9 is the engine start timing. Furthermore, if it is not necessary to manage the end of the driving simulation control, step ST15 may be omitted. Furthermore, if it is not necessary to manage the end of the command rotation speed generation control, step ST27 may be omitted and the process may return to step ST25.

[0084] 1...Automobile (vehicle), 3...Accelerator pedal, 4...Operation control device, 6...Fuel injection control device, 7...Engine, 8...Crankshaft member, 9...Torque converter, 10...CVT, 11...Drive system and vehicle body, 12...TCU, 13...Starter motor, 18...Running resistance, 19...Driver, 20...Driving simulation evaluation system, 21...Bench device, 22...Running simulator device, 23...CAN controller, 30...Dynamo, 31...Connecting shaft member, 32...Power panel, 33...Bench control device, 34...Torque sensor, 35...Dynamo encoder, 3 6...engine encoder, 41...communication port, 42...memory, 43...program, 44...speed envelope data, 45...timer, 46...CPU, 47...internal bus, 51...EGIECU, 52...EGI memory, 53...initial combustion RPM data, 54...operation model section, 55...command RPM generation module, 56...inertia correction module, 57...LPF module section, 58...vehicle model section, 59...torque converter model section, 60...CVT model section, 61...drive system and vehicle body model section, 62...running resistance model section, 63...TCU model section

Claims

1. An engine running simulation evaluation system for evaluating an engine used in a vehicle, comprising: a bench device connecting the engine and a dynamo by a connecting shaft member so that they rotate together and having a power panel capable of rotating and driving the dynamo which rotates together with the engine; and a running simulator device connected to the bench device, wherein the bench device has a torque sensor which detects the actual shaft torque acting on the connecting shaft member, and a rotation speed sensor which detects the engine rotation speed and the dynamo rotation speed of the dynamo, and the running simulator device has: a command rotation speed generation unit which outputs a command rotation speed to the bench device in order to reproduce the same rotation speed as when the engine is mounted on the vehicle in the running simulation; an inertia correction unit which performs inertia correction on the actual shaft torque detected by the bench device in accordance with the amount of fluctuation in the engine rotation speed or the dynamo rotation speed, and generates an estimated engine torque for the engine alone; and a vehicle model unit which models load elements in the vehicle which are driven by the driving force of the engine, and wherein the vehicle model unit an engine running simulation evaluation system that calculates a speed based on the rotation speed of the wheels of the vehicle when the vehicle runs under the estimated engine torque, and an engine rotation speed that changes depending on the operating state of the vehicle when the vehicle runs at the rotation speed of the wheels; and the command rotation speed generation unit outputs the engine rotation speed generated by the vehicle model unit to the bench device, and drives the dynamo to rotate at the command rotation speed.

2. The engine running simulation evaluation system according to claim 1, wherein the inertia correction unit performs inertia correction on the real shaft torque Tj based on the following equation 1 to generate the estimated engine torque Te for the engine alone, and the vehicle model unit and the command rotation speed generation unit perform their respective processes based on the estimated engine torque, which is the torque of the engine alone: ​​Te = Je dω / dt + Tj Equation 1 where Je is the rotational inertia on the engine side relative to the torque sensor, and dω / dt is the rotational angular acceleration of the engine. dω / dt may be substituted for the rotational angular acceleration of a dynamo, provided that resonance is avoided.

3. An engine running simulation evaluation system according to claim 1 or 2, wherein the driving simulator device has a low-pass filter section that filters the estimated engine torque generated by the inertia correction section and outputs the filtered estimated engine torque to the vehicle model section, the low-pass filter section filtering torque fluctuations according to the rotation angle of the engine, and the vehicle model section performs processing using the estimated engine torque after filtering by the low-pass filter section, in which torque fluctuations according to the rotation angle of the engine have been suppressed.

4. An engine running simulation evaluation system as claimed in claim 3, wherein the bench device has a fuel injection control device that is provided on the vehicle together with the engine, and the running simulator device has: a memory that records speed envelope data for the engine running simulation; and an operation model unit that generates an accelerator opening for the fuel injection control device of the bench device and outputs it to the bench device so that the speed calculated by the vehicle model unit is a speed in accordance with the speed envelope data.

Images