the first data processor calculates the estimated value using a vehicle behavior database stored in the first data processor.
In the test, each simulated machine has to operate in real time on the basis of data acquired from an actual machine operating in another location. FIG. 1 is a diagram schematically illustrating a test system according to related art in which an actual machine A1 and a simulated machine B1 are installed in a place (location 1), a simulated machine B2 and an actual machine A2 are installed in another place (location 2), the simulated machine B1 and the actual machine A1 are mechanically coupled to each other, and the actual machine A2 and the simulated machine B2 are mechanically coupled to each other.
The simulated machine B1 simulates the operation of the actual machine A2 and the simulated machine B2 simulates the operation of the actual machine A1. Accordingly, the simulated machine B1 and the actual machine A2 are connected to each other via a network and the simulated machine B2 and the actual machine A1 are connected to each other via the network.
FIG. 17 is a block diagram schematically illustrating an electrical configuration of the vehicle test apparatus DMS.
Hereinafter, a first embodiment of the invention will be described with reference to the accompanying drawings. FIG. 2 is a diagram schematically illustrating a test system 1 according to the invention in which an actual machine A1 and a simulated machine B1 are installed in location 1, a simulated machine B2 and an actual machine A2 are installed in another place (location 2), the actual machine A2 and the simulated machine B2 are mechanically coupled to each other, and the simulated machine B1 and the actual machine A1 are mechanically coupled to each other. In the embodiment of the invention, for example, it is assumed that the actual machine A2 is an electronic-control coupling mechanism which can continuously vary a ratio between driving forces of front and rear wheels from front wheels 100: rear wheels 0 in a front wheel drive to front wheels 50: rear wheels 50 by electronic control in a front wheel drive-based 4WD vehicle, and the actual machine A1 is a prime mover coupled to the coupling mechanism.
The simulated machine B2 is a motor simulating the prime mover, and the simulated machine B1 is a motor simulating the electronic-control coupling mechanism. The simulated machine B1 and the actual machine A1 are mechanically coupled to each other by a shaft, and the simulated machine B2 and the actual machine A2 are mechanically coupled to each other by a shaft. The mechanical elements in the invention are not limited to such specific examples, and arbitrary mechanical elements of a vehicle coupled to each other may be selected as the actual machine A2 and the actual machine A1.
The simulated machine B1 and the actual machine A2 are connected to each other via a network, and one or both of a rotation speed and a rotation torque of the shaft is/are transmitted as measurement data. The simulated machine B2 and the actual machine A1 are connected to each other via a network, and one or both of the rotation speed and the rotation torque (hereinafter, referred to as a “torque or rotation speed”) of the shaft is/are transmitted as measurement data via the network. A model C1 and a model C2 that estimate operations of the actual machine A2 and the actual machine A1, respectively, and that provide data on the estimated values are installed. The model C1 is connected to the simulated machine B1 and the simulated machine B1 receives data on the estimated value of the model C1. The model C2 is connected to the simulated machine B2 and the simulated machine B2 receives data on the estimated value of the model C2.
A specific configuration of the test system 1 will be described below. First, the configuration of a test system 1a according to related art will be described with reference to FIGS. 3A and 3B. FIG. 3A is a block diagram illustrating an actual machine A1 and a simulated machine B1 installed in location 1, a data processor 11 that receives data on a torque or rotation speed from an actual machine A2 and that provides the simulated machine B1 with a control target value of a torque or a control target value of a rotation speed, a propeller shaft 12 that couples the actual machine A1 and the simulated machine B1 to each other, and a measuring apparatus 13 that measures a torque or rotation speed of the propeller shaft 12. The actual machine A1 is the prime mover as described above and the simulated machine B1 is the motor.
FIG. 3B is a block diagram illustrating a simulated machine B2 and an actual machine A2 installed in location 2, a data processor 21 that receives data on a torque or rotation speed from the actual machine A1 via a network and that provides the simulated machine B2 with a control target value of a torque or a control target value of a rotation speed, a propeller shaft 22 that couples the simulated machine B2 and the actual machine A2 to each other, and a measuring apparatus 23 that measures a torque or rotation speed of the propeller shaft 22. The actual machine A2 is the electronic-control coupling mechanism as described above and the simulated machine B2 is the motor. A flywheel 25 simulating a rear wheel tire is coupled to the actual machine A2.
In this configuration, a test procedure which is performed by the data processor 11 connected to the simulated machine B1 according to the related art will be described with reference to FIG. 4 illustrating a flowchart. When receiving data on a torque or rotation speed from the actual machine A2 via the network in each communication cycle (the communication cycle is not limited, and is set to, for example, 10 msec) (step S1), the data processor 11 calculates the control target value of the torque or rotation speed on the basis of the received data (step S2). The data processor 11 updates the control target value previously calculated and stored in a memory of the data processor 11 using the calculated control target value (step S3). The data processor 11 performs motor driving control on the simulated machine B1 using the updated control target value (step S4). The acquired control target value is recorded on the memory.
The test procedure which is performed by the data processor 21 connected to the simulated machine B2 is similarly performed. FIG. 5 is a graph illustrating a temporal variation of measurement data on a torque or rotation speed acquired from the actual machine A2, the control target value for the simulated machine B1, and measurement data on a torque or rotation speed measured by a measuring apparatus 13. The measurement data on the actual machine A2 is indicated by a thin solid line, the control target value is indicated by a thick step-like dotted line, and the measurement data measured by the measuring apparatus 13 is indicated by a curved solid line. The communication cycle is indicated by a vertical dotted line.
As can be seen from FIG. 5, the measurement data on the actual machine A2 continuously varies. However, since the communication cycle of the network is present as described above, the timing of receiving the measurement data on the actual machine A2, which is used by the data processor 11 as a basis for calculating the control target value for the simulated machine B1, is confined to the communication cycle. Accordingly, when the measurement data on the actual machine A2 finely varies, the variation is not followed appropriately and the control target value for the simulated machine B1 varies in a step-like shape. That is, until the next communication cycle, the measurement data on the torque or the rotation speed of the actual machine A2 is fixed and the control target value calculated on the basis of the measurement data at the time of the start of the current communication cycle is held as the calculated value. Depending on details of the control performed on the simulated machine B1 by the data processor 11, the overshoot of the measurement data measured by the measuring apparatus 13 is observed at the timing at which the step rises.
FIG. 6 is an enlarged view of one communication cycle extracted from FIG. 5. Both ends (cross marks) of one communication cycle represent the time point at which the measurement data on the actual machine A2 is received, and each control cycle of the data processor 11 in the communication cycle is indicated by a circle mark. The control target value for the simulated machine B1 does not vary in the communication cycle, corresponds to the flat part of a step, and is fixed to a constant value even when the measurement data on the actual machine A2 varies. Therefore, the real-machine reproduction accuracy of the simulated machine B1 cannot be said to be good. When the overshoot increases, the measurement data may be out of control in the end and may diverge. It is preferable to shorten the communication cycle, but the communication speed allowed for the network is limited.
Therefore, in the invention, a configuration of a test system 1 in which a simulation estimating device 14 is added to the data processor 11 and a simulation estimating device 24 is added to the data processor 21 is employed as illustrated in FIGS. 7A and 7B. FIG. 7A illustrates the configuration in location 1, and FIG. 7B illustrates the configuration in location 2. The configuration other than the simulation estimating devices 14 and 24 is the same as that illustrated in FIGS. 3A and 3B. The simulation estimating device 14 estimates a variation of measurement data in each control cycle until the data processor 11 receives the next measurement data after receiving the measurement data on the actual machine A2 in each communication cycle. Then, the data processor 11 calculates the control target value on the basis of the measurement data on the actual machine A2 received in each communication cycle and data on a model state quantity (a model state value) (hereinafter, referred to as an “estimated value”) estimated in each control cycle. The simulation estimating device 24 similarly estimates a variation of measurement data until the data processor 21 receives the next measurement data after receiving the measurement data on the actual machine A1, and calculates the control target value on the basis of the received measurement data and the estimated value in each control cycle.
FIG. 8 is a flowchart illustrating a test procedure according to the invention which is performed by the data processor 11 connected to the simulated machine B1. When the data processor 11 receives data on a torque or rotation speed from the actual machine A2 via a network in each communication cycle (step T1), the simulation estimating device 14 calculates the estimated value of the torque or rotation speed in each control cycle (it is assumed that the control cycle is shorter than the communication cycle and, for example, the communication cycle is 10 msec and the control cycle is 2 msec), on the basis of the received data (step T2), and transmits the calculated estimated value to the data processor 11. The data processor 11 calculates the control target value for the simulated machine B1 using the calculated estimated value (step T3). The control target value previously calculated and stored in the memory in the data processor 11 is updated in each control cycle, by using the control target value (step T4). The simulated machine B1 is controlled using the updated control target value (step T5).
The test procedure, which is performed by the data processor 21 connected to the simulated machine B2 and the simulation estimating device 24, is performed in the same way. Thus, the variation of the torque or rotation speed of the actual machine is estimated using the simulation estimating device, and the control target value for the simulated machine is calculated using the estimated data in each control cycle, instead of using the data on the torque or rotation speed, which is received from the actual machine via the network in each communication cycle, without changing the data in the corresponding communication cycle.
FIG. 9 is a graph illustrating the data on the torque or rotation speed measured in the actual machine and the estimated value of the simulation estimating device. The measurement data on the actual machine is indicated by a thin solid line, and the estimated value is indicated by a thick dotted line having a polygonal curve shape. The communication cycles are indicated by vertical dotted lines. FIG. 10 is an enlarged view of one communication cycle extracted from FIG. 9. Both ends (cross marks) of one communication cycle represent time points at which the measurement data on the actual machine is received, and each control cycle of the data processor in the communication cycle is indicated by a circle mark. Thus, since the control target value is calculated on the basis of the estimated value, the control target value appropriately follows the measurement data on the actual machine (in other words, the followability of the control target value with respect to the measurement data on the actual machine is appropriate). As a result, the amount of rising of a step as illustrated in FIG. 5 decreases, and the overshoot also decreases accordingly. It is possible to improve the real-machine reproduction accuracy of the simulated machine.
Abnormal operation correcting control according to a modified example of the invention will be described. In the above-mentioned test procedure according to the invention, the simulation estimating device estimates the measurement data on the actual machine by performing a simulation estimating process. For example, when the measurement data on the actual machine peculiarly varies, it is considered that the estimated value may be different from the measurement data on the actual machine. For example, FIG. 11 is an enlarged view illustrating this case where measurement data Xa on the actual machine greatly varies in adjacent communication cycles (cross marks) and is greatly different from the estimated value Xm calculated in each control cycle (circle marks). In this case, when the control target value is calculated on the basis of the estimated value, the control target value calculated on the basis of the estimated value used hitherto and the control target value calculated on the basis of the measurement data on the actual machine are greatly different from each other at the time point at which the measurement data on the actual machine is received in the next communication cycle.
Therefore, as illustrated in the flowchart of FIG. 12, for example, when the data processor 11 for the simulated machine B1 receives data Xa that is the measurement data on the actual machine A2 via the network in each communication cycle (step T1), the data processor 11 compares the received data Xa with the estimated value Xm and determines whether the absolute value of the difference therebetween is greater than an abnormal state correction threshold value Xc (step T11). When it is determined that the absolute value of the difference is equal to or smaller than the abnormal state correction threshold value Xc, an abnormal state correction flag is turned off (step T12). Then, the data processor 11 determines whether an abnormal state correction flag of another location transmitted from the other location is on (step T13). When the abnormal state correction flag is off, the data processor 11 calculates the estimated value as illustrated in steps T2 to T5 in FIG. 8 (step T2), calculates the control target value for the simulated machine B1 using the calculated estimated value (step T3), updates the control target value previously calculated and stored in the memory of the data processor 11 in each control cycle (step T4), and controls the simulated machine B1 using the updated control target value (step T5).
When it is determined in step T13 that the abnormal state correction flag of the other location is on, the data processor sets a normal-state control target value transmitted from the other location as the control target value for the simulated machine B1 without using the estimated value (step T14), and controls the simulated machine B1 using the control target value (steps T3 to T5). In this way, the normal-state control target value for the simulated machine B2 processed in the other location and transmitted from the other location is employed. In order to reduce a communication load, the normal-state control target value is transmitted, instead of transmitting the measurement data, such as the torque or the rotation speed of the actual machine A2 measured in the other location.
When it is determined in step T11 that the absolute value of the difference between the data Xa and the estimated value Xm is greater than the abnormal state correction threshold value Xc, the abnormal state correction flag is turned on in step T15 (step T15). Then, the control target value is calculated on the basis of the measurement data Xa on the actual machine A2 instead of the estimated value Xm (step T16). This control target value is referred to as the “normal-state control target value” with a meaning of a control target value corrected and calculated to correct and return the state to a normal state.
The data processor 11 transmits the normal-state control target value to the data processor 21 in the other location (step T17), in order to set the flag so that both simulated machines are regarded as being in an abnormal state when either one of the simulated machines is deviated. The data processor 21 sets the normal-state control target value as the control target value for the simulated machine B2 without using the estimated value and controls the simulated machine B2 using the control target value (steps T3 to T5).
By notifying the data processor in the other location that the measurement data on the actual machine is different from the estimated value estimated by simulation in the one location, it is possible to prevent the control target value for the simulated machine B2 and the measurement data on the actual machine A1 from being greatly different from each other by correction in the other location. The invention is not limited to the above-mentioned embodiment, and various modifications may be made to the embodiment without changing the scope of the invention. For example, the actual machine A2 may be a steering system and the actual machine A1 may be a tire system. In this case, the simulated machine B1 is a motor for rotationally driving a tire and the simulated machine B2 is a motor for applying a reaction force of the tire to the rotation of a steering shaft. The actual machine A2 may be a wheel-in motor of a vehicle and the actual machine A1 may be a tire system.
Hereinafter, a second embodiment of the invention will be described with reference to the accompanying drawings. FIG. 13 is a diagram schematically illustrating a vehicle test system 100 according to the second embodiment of the invention in which a driving simulator DS is installed in a certain place (location 1), a vehicle test apparatus DMS is installed in another place (location 2), and the vehicle test apparatus DMS and the driving simulator DS are connected to each other via a communication line 9 such as an optical cable, a coaxial cable, and the like. In FIG. 13, COM1 represents a computer of the driving simulator DS and COM2 represents a computer of the vehicle test apparatus DMS.
In the embodiment of the invention, in the driving simulator DS, input devices such as a steering wheel 91, an accelerator pedal 92, a brake pedal 93, and a shift lever 94 are mounted, and a monitor 95 that displays a landscape appearing through a vehicle window is also mounted, as illustrated in FIG. 14. The steering wheel 91 is connected to a reaction force motor (not illustrated) for simulatively applying a reaction force which a driver receives from a road surface. Actuators (not illustrated) for applying various motions of rolling, pitching, and yawing are provided for a driver's seat.
Data pieces such as a steering angle θ of the steering wheel 91, a depression amount A of the accelerator pedal 92, and a depression force B of the brake pedal 93 are input to the computer COM1 of the driving simulator DS. The driving simulator DS is connected to a reaction force motor driver 63 (see FIG. 16) that simulatively creates reaction force data which the driver receives from the road surface and that drives the reaction force motor (not illustrated) on the basis of the reaction force data, in response to a command from the computer COM1. The computer COM1 of the driving simulator DS is connected to a motion controller 64 (see FIG. 16) that drives actuators to realize motions such as a roll angle r, a pitch angle p, and a yaw angle y (these three parameters are referred to as “posture parameters”) at the time of acceleration and deceleration, cornering, and braking. An image driver 67 (see FIG. 16) is also provided which controls driving of the monitor 95 so as to move and rotate a landscape depending on a traveling distance. The landscape displayed on the monitor 95 moves on the basis of an instruction of the image driver 67. The directions in which the landscape moves depending on the roll angle r, the pitch angle p, and the yaw angle y are indicated by arrows on the monitor 95 of FIG. 14.
FIG. 15 is a perspective view schematically illustrating an appearance of the vehicle test apparatus DMS. The vehicle test apparatus DMS includes a test piece-mounting vehicle body 2 on which four axles 21S, 22S, 23S, and 24S (where 21S and 22S are hidden due to other members and thus are not illustrated) corresponding to four vehicle wheels of a front-left wheel, a front-right wheel, a rear-left wheel, and a rear-right wheel are mounted and test pieces are mounted, a first motion base 3 that supports the test piece-mounting vehicle body 2 and that causes the test piece-mounting vehicle body 2 to move with 6 degrees of freedom, and four second motion bases 4, 5, 6, and 7 that support the axles 21S, 22S, 23S, and 248, respectively, and that causes the axles 21S, 22S, 23S, and 24S to move with 6 degrees of freedom.
In FIG. 15, a front end of the test piece-mounting vehicle body 2 is denoted by reference sign 2f, and a rear end of the test piece-mounting vehicle body 2 is denoted by reference sign 2r. The outer end parts of four axles 21S, 22S, 23S, and 24S of the test piece-mounting vehicle body 2 are connected to output shafts of four electric motors (hereinafter, referred to as “external force applying motors”) 31, 32, 33, and 34 that apply a rotational force to the axles. The electric motors 31, 32, 33, and 34 are configured to individually apply the same rotational forces as the rotational forces (external forces), which are applied to the axles from the outside when a real vehicle travels, to the corresponding axles 21S, 22S, 23S, and 24S. Examples of the external forces include rotational loads applied to the axles due to road friction when a real vehicle travels and rotational forces applied to the axles via the road surface when the real vehicle descends down a slope.
Test pieces which are various mechanical elements of a vehicle are mounted on the test piece-mounting vehicle body 2. In this embodiment, an electric power steering (EPS) system 40 and a rear wheel driving module 50 that drives the axle 23S for the rear-left wheel and the axle 24S for the rear-right wheel by the use of an electric motor are mounted as test pieces on the test piece-mounting vehicle body 2. In this embodiment, the EPS 40 is a column assist type EPS. As known well, the EPS 40 includes a steering wheel 81, a turning mechanism (not illustrated) that turns the front wheels by in accordance with the rotation of the steering wheel 81, and a steering assist mechanism 83 that assists a driver's steering. The steering wheel 81 and the turning mechanism 82 are mechanically connected to each other via a steering shaft.
The turning mechanism includes a rack and pinion mechanism having a pinion disposed at the lower end of the steering shaft and a rack shaft provided with a rack fitted to the pinion. The ends of the rack shaft are connected to the front wheels via tie rods, knuckle arms, and the like. The steering assist mechanism 83 includes an electric motor (hereinafter, referred to as an “assist motor”) that generates a steering assist force and a speed reduction mechanism that transmits an output torque of the assist motor to the steering shaft.
The EPS 40 further includes an electronic control unit (ECU) (hereinafter, referred to as an “EPS ECU”) that controls the assist motor and a linear displacement sensor that detects a displacement in the axial direction of the rack shaft. The rear wheel driving module 50 includes an electric motor (hereinafter, referred to as a “rear wheel driving motor”) that rotationally drives the axles 23S and 24S for the rear wheels, a transmission mechanism that transmits the rotational force of the rear wheel driving motor to the axles 23S and 24S for the rear wheels, an ECU (hereinafter, referred to as a “rear wheel driving-motor ECU”) that controls the rear wheel driving motor, and a rotation angle sensor that detects the rotation angle(s) of one or both of the axles 23S and 24S for the rear wheels. The transmission mechanism includes a clutch and a reduction mechanism. The transmission mechanism may include one of the clutch and the reduction mechanism.
The motion bases 3, 4, 5, 6, and 7 are fixed to a plate 10 placed on the floor. As known well, each of the motion bases 3, 4, 5, 6, and 7 includes a fixed base 110 fixed to the plate 10, a moving base 120 disposed above the fixed base 110, a piston-like actuator 130 that is connected between the fixed base 110 and the moving base 120 and that causes the moving base 120 to move with 6 degrees of freedom (in forward, rearward, rightward, leftward, upward, downward, roll, pitch, and yaw directions), and a motion controller (not illustrated) that controls the driving of the actuator 130. The actuator 130 includes six electric cylinders. The motion controller includes a driver circuit that applies a drive current to a drive motor provided in the actuator 130 in response to an input of a signal corresponding to each of the motions of the 6 degrees of freedom.
The test piece-mounting vehicle body 2 is fixed to the moving base of the first motion base 3 in a state where the central part of the test piece-mounting vehicle body 2 is mounted thereon. That is, the central part of the bottom surface of the test piece-mounting vehicle body 2 is attached to the top surface of the moving base of the first motion base 3. That is, the test piece-mounting vehicle body 2 is supported by the first motion base 3. The motor bodies of the external force applying motors 31, 32, 33, and 34 are fixed to the moving bases 120 of the second motion bases 4, 5, 6, and 7, respectively, with elastic sheet members 30 interposed therebetween. That is, the motor bodies of the external force applying motors 31, 32, 33 and 34 are supported by the second motion bases 4, 5, 6, and 7, respectively, with the elastic sheet members 30 interposed therebetween. In other words, the axles 21S, 22S, 23S, and 24S are supported by the second motion bases 4, 5, 6, and 7, respectively, with the elastic sheet members 30 and the corresponding external force applying motors 31, 32, 33, and 34 interposed therebetween. Motor controllers 35, 36, 37, and 38 (see FIG. 17) that control the external force applying motors 31, 32, 33, and 34, respectively, are mounted on the test piece-mounting vehicle body 2.
The same rotational forces as the rotational forces (external forces), which are applied to the axles from the outside when a real vehicle travels, can be individually applied to the corresponding axles 21S, 22S, 23S, and 24S by the use of the external force applying motors 31, 32, 33, and 34. Accordingly, it is possible to reproduce driving loads and suspension behavior based on the real driving condition. In the vehicle test apparatus DMS, various vehicle postures can be reproduced by controlling the driving of the actuator 130 for the first motion base 3 and individually controlling the driving of the actuators 130 for the second motion bases 4, 5, 6, and 7. Therefore, by controlling the actuators 130 for the motion bases 3, 4, 5, 6, and 7 as a whole, it is possible to reproduce various vehicle traveling postures including rolling, pitching, and yawing.
FIG. 16 is a block diagram schematically illustrating an electrical configuration of the driving simulator DS. As illustrated in FIG. 16, the data pieces such as the steering angle θ of the steering wheel 91, the depression amount A of the accelerator pedal 92, and the depression force B of the brake pedal 93 are input to a network terminal 61 in the computer COM1 and are transmitted to the vehicle test apparatus DMS therefrom. The data pieces θ, A, and B are also input to a vehicle behavior database 62 installed in the computer COM1.
The vehicle behavior database 62 reads reaction force data corresponding to the steering angle θ input to the vehicle behavior database in response to an instruction of a calculation unit (not illustrated) of the computer COM1 and supplies the read reaction force data to the reaction force motor driver 63. The vehicle behavior database 62 reads the traveling distance, the roll angle r, the pitch angle p, and the yaw angle y based on the data pieces θ, A, and B and supplies the read data pieces to the motion controller 64 and the image driver 67.
FIG. 17 is a block diagram schematically illustrating an electric configuration of the vehicle test apparatus DMS. The vehicle test apparatus DMS includes a computer COM2 and a body portion 1000 of the vehicle test apparatus DMS. The assist motor 41, the EPS ECU 42 that controls the assist motor 41, the rear wheel driving motor 51, a rear wheel driving motor ECU 52 that controls the rear wheel driving motor 51, the motion controllers 3C, 4C, 5C, 6C, and 7C that drive the motion bases 3, 4, 5, 6, and 7, respectively, and the motor controllers 35, 36, 37, and 38 are mounted on the body portion 1000 of the vehicle test apparatus DMS. The motor controllers 35, 36, 37, and 38 are devices that drive the external force applying motors 31, 32, 33, and 34, respectively.
The computer COM2 connected to the computer COM1 (see FIG. 13) of the driving simulator DS via the communication line 9 is a device that controls the motion controllers 3C, 4C, 5C, 6C, and 7C for the motion bases 3, 4, 5, 6, and 7 of the vehicle test apparatus DMS and the motor controllers 35, 36, 37, and 38 mounted on the vehicle test apparatus DMS. The control function of the computer COM2 is implemented by a program installed in the computer.
The EPS ECU 42 includes a linear displacement sensor (not illustrated) that detects a displacement in the axial direction of the rack shaft. The rear wheel driving motor ECU 52 includes a rotation angle sensor (not illustrated) that detects both or one rotation angle of the axles 23S and 24S of the rear wheels. The data pieces such as the steering angle θ, the depression amount A of the accelerator pedal, and the depression force B of the brake pedal corresponding to the driver's driving operation are input to a network terminal 73 from the driving simulator DS via the communication line 9. The data on the steering angle θ is supplied to the EPS ECU 42 mounted on the vehicle test apparatus DMS. The data on the depression amount A of the accelerator pedal is supplied to the rear wheel driving motor ECU 52 mounted on the vehicle test apparatus DMS. The data piece on the depression force B of the brake pedal is supplied to a vehicle behavior calculating unit 71 of the computer COM2.
The EPS ECU 42 determines the steering torque on the basis of the data on the steering angle θ supplied from the driving simulator DS and controls the driving of the assist motor 41 on the basis of the determined steering torque. The EPS ECU 42 measures a displacement of the rack shaft included in the EPS 40 in the axial direction (hereinafter, referred to as a “rack shaft displacement”) and a displacement speed of the rack shaft in the axial direction (hereinafter, referred to as a “rack shaft displacement speed”) on the basis of the output signal of the linear displacement sensor and sends the measured values to the computer COM2.
The rear wheel driving motor ECU 52 determines a torque command value for the rear wheel driving motor 51 on the basis of the data on the depression amount A of the accelerator pedal supplied from the driving simulator DS and controls the driving of the rear wheel driving motor 51 on the basis of the determined torque command value. The rear wheel driving motor ECU 52 measures the rotation speeds (hereinafter, referred to as an “axle rotation speed”) of the axles 23S and 24S of the rear wheels on the basis of the output signal of the rotation angle sensor and sends the measured values to the computer COM2.
The computer COM2 includes the network terminal 73, the vehicle behavior calculating unit 71, a command value generating unit 72, and a vehicle behavior database 74. The vehicle behavior calculating unit 71 performs a calculating operation using software such as a vehicle model 75. Here, the vehicle model 75 is software configured to simulate the behavior of a real vehicle having the test pieces mounted thereon, and is a model that generates position and posture of the vehicle body, position and posture of the vehicle wheels and the external forces applied to the axles, which correspond to the driving condition, on the basis of the data pieces such as the depression force B of the brake pedal, the rack shaft displacement, the rack shaft displacement speed, and the axle rotation speed acquired from the driving simulator DS.
The brake depression force information acquired from the network terminal 73, the rack shaft displacement and the rack shaft displacement speed sent from the EPS ECU 42, and the axle rotation speed sent from the rear wheel driving motor ECU 52 are input to the vehicle behavior calculating unit 71. The vehicle behavior calculating unit 71 generates the position and posture of the vehicle body, the position and posture of the vehicle wheels, and the external forces applied to the axles, which correspond to the driving condition simulated by the driving simulator DS, on the basis of the input information using the vehicle model 75.
The command value generating unit 72 generates posture command values for the motion bases 3, 4, 5, 6, and 7 on the basis of the data on the position and posture of the vehicle body and the position and posture of the vehicle wheels generated by the vehicle behavior calculating unit 71 in each predetermined cycle. The command value generating unit 72 generates the torque command values for the external force applying motors 34, 35, 36, and 37 on the basis of the external forces applied to the axles and generated by the vehicle behavior calculating unit 71.
The vehicle behavior database 74 is a storage device that stores the output data such as the posture command values and the torque command values generated by the command value generating unit 72 as a database. The posture command values for the motion bases 3, 4, 5, 6, and 7 generated by the command value generating unit 72 are sent to the vehicle behavior database 74. The posture command values are also sent to the motion controllers 3C, 4C, 5C, 6C, and 7C for the corresponding motion bases 3, 4, 5, 6, and 7. The motion controllers 3C, 4C, 5C, 6C, and 7C control the corresponding actuators 130 on the basis of the posture command values sent from the command value generating unit 72. Accordingly, the moving bases 120 of the motion bases 3, 4, 5, 6 and 7 move so as to be in postures corresponding to the posture command values.
The torque command values for the external force applying motors 31, 32, 33, and 34 generated by the command value generating unit 72 are sent to the vehicle behavior database 74. The torque command values are also sent to the corresponding motor controllers 35, 36, 37, and 38. The motor controllers 35, 36, 37, and 38 control the corresponding external force applying motors 31, 32, 33, and 34 on the basis of the torque command values sent from the command value generating unit 72. Accordingly, motor torques corresponding to the torque command values are generated from the external force applying motors 31, 32, 33, and 34.
According to the embodiment of the invention, in the driving simulator DS, the input devices such as the steering wheel 91, the accelerator pedal 92, the brake pedal 93, and the shift lever 94 are operated, and a preliminary behavior estimating test is performed so as to estimate the vehicle behavior in all steering input patterns. The output data such as the posture command values or the torque command values generated by the command value generating unit 72 are stored and accumulated in the vehicle behavior database 74 of the vehicle test apparatus DMS in correspondence with the plural operation data pieces such as the brake depression force B, the rack shaft displacement, the rack shaft displacement speed, and the axle rotation speed, which indicate contents of the vehicle operation signal.
In the preliminary behavior estimating test, (1) a driver in the driving simulator DS may actually operate the input devices, and the data such as the steering angle θ, the depression amount A of the accelerator pedal, and the brake depression force B based on the driver's driving operation may be transmitted to the vehicle test apparatus DMS via the communication line 9; or (2) the computer COM1 of the driving simulator DS may simulatively generate the signals to be output if the input devices are operated and the generated signals may be transmitted to the vehicle test apparatus DMS.
When the preliminary behavior estimating test ends, the data pieces such as the posture command values or the torque command values have been accumulated in the vehicle behavior database 74, and thus, these data pieces are transmitted to the vehicle behavior database 62 installed in the computer COM1 illustrated in FIG. 16. The transmission method is not particularly limited. For example, the data in the vehicle behavior database 74 may be transmitted or copied via the communication line 9 or via a portable memory when the preliminary behavior estimating test ends, or two vehicle behavior databases 74 and 62 may be interactively synchronized via the communication line 9 during the preliminary behavior estimating test.
Therefore, the driving simulator DS can be operated using the vehicle behavior database 62 regardless of whether the driving simulator and the vehicle test apparatus perform data communication therebetween in real time during operation of the driving simulator. In order to operate the driving simulator to collect test data pieces on the test pieces, the output data such as the posture command values or the torque command values generated by the command value generating unit 72 may be stored and accumulated in the vehicle behavior database 74 by performing data communication between the driving simulator and the vehicle test apparatus in real time.
According to the invention, the driving simulator is operated using the vehicle behavior database 62 of the driving simulator instead of feeding back and using the vehicle behavior data in real time during operation the driving simulator. As a result, even in a state where a considerable delay occurs in the data communication between the driving simulator DS and the vehicle test apparatus DMS, it is possible to improve followability of data, and thus the driving simulator DS can accurately simulate the state of the test piece-mounting vehicle body 2 including the test pieces.