JPH05341709A - Control method for road simulation device - Google Patents

Abstract

PURPOSE:To surely obtain an exciting signal in an early stage by correcting successively the exciting signal until an arithmetic error enters into a threshold, and repeating an excitation by the corrected exciting signal. CONSTITUTION:By using a test signal determined in advance as an exciting signal, a test vehicle is excited, a measurement of acceleration and distortion is executed by accelerometers C1, C2 and a strain gage C3, and from the measured acceleration signal and distortion signal, and the exciting signal, a transfer function is calculated. Subsequently, an excitation by an arithmetic exciting signal is executed, an error between outputs of the detectors C1-C3 and repeated correction process target data caused by the excitation is calculated, and with respect to a block in which an arithmetic error does not enter into a threshold, the arithmetic error and an inverse transfer function and a correction valve consisting of the product being common to all blocks are added to the exciting signal as a new exciting signal, and the exciting signal is corrected successively until the arithmetic error enters into the threshold. By the corrected exciting signal, the excitation is repeated, and the converged block is excluded from the next excitation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a road simulation apparatus capable of reproducing an actual road load on a vehicle on a test bench.

[0002]

2. Description of the Related Art When a road simulation is carried out by a road simulation device, output from a detector provided on a vehicle, that is, actual traveling data is collected by actual traveling of a vehicle in a field, and target data is obtained based on the actual traveling data. To generate. On the other hand, the test vehicle is test-excited by an exciter to calculate a transfer function, and an inverse transfer function is calculated based on the calculated transfer function. Fourier transform the generated target data, multiply the Fourier transform target data by the inverse transfer function, perform Fourier inverse transform of the multiplication output to calculate the excitation signal, and drive the exciter with the calculated excitation signal. Road simulation is performed by.

When there are three detectors, the arithmetic expression is matrix
Indicated by Target signal is d₁, D ₂, D₃And then
Fourier transform target signal is D₁, D₂, D₃And then reverse transmission
Function matrix [G]^-1, Fourier excitation signal
V₁, V₂, V₃And when

[0004]

[Equation 1]

The excitation signals v ₁ , v ₂ , v ₃ are obtained by subjecting the Fourier excitation signal obtained by this calculation to the inverse Fourier transform.

In this case, when the actual traveling distance is long, the actual traveling data becomes a considerable number and the target data number also becomes a considerable number. However, as described above, in the road simulation, the Fourier transform of the target data is necessary, and further the inverse Fourier transform is necessary for the calculation of the excitation signal,
The Fourier transform and the inverse Fourier transform are performed by a fast Fourier transform process and a Fourier inverse transform process by digital processing. However, in the case of this processing, the number of data that can be processed is limited to 2 to the n-th power (n is an integer). If the number of data due to this limitation is 1024, the number of detection points of the actual traveling data is large, and the target data to be reproduced is 10
It often exceeds 24 data.

When the target number of data is large as described above,
The total target data is divided into a plurality of blocks so that the number of data that can be processed is the n-th power and overlaps with the adjacent block at the end over the predetermined number of data. This process focuses on the first block, calculates the excitation signal for the target data of the first block, performs excitation with the calculated excitation signal, and detects the error between the excitation result and the target data. Then, the excitation signal is corrected and repeated until the detection error falls within the predetermined range,
When the error falls within the specified range, the excitation signal for the first block is stored, the process proceeds to the next block that is continuous, the same processing is performed for all blocks, and when the excitation signal is stored over all blocks. , In the overlapping range of the blocks, the excitation signals are combined at a level difference to generate one continuous excitation signal over all the blocks.

[0008]

However, according to the above-mentioned conventional method, the error is easily converged because the processing is performed for each block sequentially from the first block to the next block. Since it is necessary to sequentially perform correction, there is a problem that it takes a lot of time and labor to obtain an excitation signal when the number of target data is large, that is, when the number of blocks is large.

An object of the present invention is to provide a control method for a road simulation device that can obtain an excitation signal reliably and early.

[0010]

A method for controlling a road simulation apparatus according to the present invention is a method for controlling a road simulation apparatus in which a vehicle is forcibly vibrated by vibrating means so as to obtain an actual road surface load. The output data obtained from the detector provided on the vehicle by actual traveling is divided into a plurality of blocks so that the number of data is within a predetermined range and overlaps with the adjacent block at the end over the predetermined number of data. And a first step of obtaining target data for the iterative correction process, and a transfer function is calculated based on the output of the detector when the vehicle is vibrated by a predetermined test signal by the road simulation device, and the calculated transfer function is calculated from the calculated transfer function. Second calculation of inverse transfer function
And the inverse transfer function calculated in the second step and the iterative correction process target data obtained in the first step, the initial excitation signal is calculated, and excitation is performed by the calculated excitation signal, The difference between the output of the detector due to the vibration and the target data for the iterative correction process is calculated as an error, and the calculation error, the inverse transfer function, and a predetermined coefficient set in advance for a block in which the calculation error does not fall within the threshold value. A correction value consisting of the product of and is added to the previous excitation signal, and the excitation signal is sequentially corrected as a new excitation signal until the calculation error reaches the threshold value.
And the excitation signals for the blocks in which all the calculation errors are within the threshold value are sequentially stored, and when this storage is completed for all the blocks, the adjacent excitation signals in the overlapping portion with the adjacent block are stored. And a fourth step of connecting the excitation signal at the same position as the total excitation signal.

The leading end of each iterative-correction-process target data portion which overlaps the iterative-correction-process target data of an adjacent block has a leading end of "0" and monotonically increases from the "0". A multiplication process with a window function whose end is “1” may be performed. Further, the connection with the addition signal of each block may be performed in an overlapping portion of the target data for the iterative correction process and in a unit other than the multiplication processing unit with the window function. Furthermore, the coefficient used for the calculation of the correction value may be a value that exceeds 0 and is within 1.

[0012]

According to the method for controlling a road simulation apparatus of the present invention, a detector provided in a vehicle so that the number of data is within a predetermined range and overlaps with the adjacent block at the end over the predetermined number of data. The output data obtained from the actual running of the vehicle is divided into a plurality of blocks to obtain the target data for the iterative correction process, and the initial excitation signal is calculated based on the calculated inverse transfer function and the target signal for the iterative correction process. , The excitation by the calculation excitation signal is performed,
The difference between the output of the detector due to the excitation and the target data for the iterative correction process is calculated as an error, and the calculation error and the inverse transfer function are common to all blocks for which the calculation error does not fall within the threshold value. A correction value consisting of the product of the coefficient and is added to the previous excitation signal, and the excitation signal is sequentially corrected as a new excitation signal until the calculation error reaches the threshold, and the excitation is repeated with the corrected excitation signal. Be done.

In this case, the block in which the calculation error has converged is excluded from the next excitation, so that the calculation error can be converged earlier. Further, the coefficient can be set by paying attention to a block having a large calculation error, and the speed at which the calculation error converges within the threshold value becomes faster. The excitation signals for the blocks in which the calculation error is within the threshold value are sequentially stored, and when this storage is completed over all blocks, in the overlap portion with the adjacent block, the same as the excitation signal of the adjacent block, The excitation signal having no step is connected to the excitation signals of the adjacent blocks to obtain the total excitation signal.

[0014]

EXAMPLES The present invention will be described below with reference to examples.

FIGS. 1 and 2 are flowcharts of the first embodiment of the present invention, FIGS. 3 and 4 are schematic explanatory diagrams of target data generation in the first embodiment of the present invention, and FIG. It is a side view showing an example of a road simulation device to which the invention is applied, and illustrates a case of a motorcycle.

In FIG. 5, reference numeral 1 indicates a motorcycle to be excited, and the front and rear wheels of the vehicle have been removed in advance. Reference numeral 2 is a front axle rotatably supported by a vehicle body frame (not shown) of the motorcycle, and the axle 2 is supported by a telescopic type telescopic front suspension 3. Reference numeral 5 is a rear axle, and the axle 5 is attached to a rear fork 6 which is swingably supported by a rear cushion (not shown) combined with a link mechanism.

Reference numeral 10 is an axle vibrating means for directly vibrating the front and rear axles 2 and 5 of the motorcycle 1. The axle vibrating means 10 is actually used for the axles 2, 5
And a controller 12 for controlling the mechanical part 11.

Mechanical part 11 of axle vibrating means 10
Is a first vibrator 14 that vertically vibrates the rear axle 5 of the motorcycle 1, a second vibrator 15 that vertically vibrates the front axle 2, and a front axle 15. And a third vibration exciter 16 that vibrates 2 in the front-rear direction. The first, second, and third shakers 14, 15, 16
For this purpose, a reciprocating hydraulic cylinder that can apply both tension and compression force is used.

Connecting rods 14b and 15b are provided at the tips of the piston rods 14a and 15a of the first and second vibrators 14 and 15, respectively.
One end of each of them is pin-coupled, and the connecting rods 14b,
The other end of 15b is pin-connected to the axles 2 and 5, respectively. In addition, the piston rod 16 of the third vibrator 16
One end 18b of the oscillating plate 18 is pin-connected to the tip of a via a link 16aa. The swing plate 18 is formed in a triangular shape in a side view, and has a central base end portion 18a.
Is rotatably supported on the upper part of the support body 19. The other end 18c of the oscillating plate 18 is pin-coupled to one end of a vibrating rod 20 extending in a substantially horizontal direction, and the other end of the vibrating rod 20 is pin-coupled to the front axle 2.

That is, when the piston rod 16a of the third vibrator 16 expands and contracts in the vertical direction, the front axle 2 of the motorcycle 1 is moved through the link 16aa, the rocking plate 18, and the vibration rod 20. It has a structure that is excited in the front-back direction. A load detecting means 21 is provided on the vibrating rod 20.

Reference numeral 25 is a rigid reaction force jig for restricting the movement of the motorcycle 1 in the front-rear direction. The axle 5 on the rear side of the motorcycle is connected to the reaction jig 25 via a link rod 26.

In order to obtain the output vibration accompanying the vibration of the first vibration exciter 14 and the output signal at the time of actual traveling, the accelerometer C is placed at a position above the axle 5 on the rear fork 6.
1 is attached, and the behavior of the rear fork 6 is measured by the output of the accelerometer C1. Further, in order to obtain an output signal accompanying the vibration of the second shaker 15 or the third shaker 16 and an output signal at the time of actual traveling, an accelerometer C2 is attached at a position above the front axle 2. , The inner pipe 3 below the bottom bridge of the front suspension 3
The strain gauge C3 is attached to a, and the behavior of the axle 2 and the strain of the inner pipe 3a are measured by the output signals of the accelerometer C2 and the strain gauge C3.

Next, this embodiment will be described with reference to the flowchart of FIG. When performing a road simulation of a vehicle, first, actual traveling is performed, acceleration and strain are measured by accelerometers C1 and C2 and strain gauge C3 during actual traveling, an actual traveling signal is obtained, and the actual traveling signal is converted into a digital signal. The actual travel data is obtained by conversion (step S1).
FIG. 3A schematically shows actual traveling data obtained by actual traveling.

The actual traveling data obtained in step S1 is a number of data within a range capable of being processed at one time, and a plurality of all the actual traveling data are provided so as to overlap the adjacent block at the end over a predetermined number of data. Is divided into blocks. The divided blocks are as schematically shown in FIG. A so-called window function in which the tip of the block is “0”, the monotonically increasing from the tip of “0”, and the other end side is “1” is multiplied by the portion overlapping with the block next to each block, Target data for the iterative correction process is generated from each actual traveling data divided into blocks (step S2). FIG. 3C schematically shows the generated iterative correction process target data, and FIG. 4 schematically shows one block of the iterative correction process target data subjected to the window function multiplication processing.

Next, the test vehicle is vibrated by the road simulation device using a predetermined test signal as a vibration signal, and acceleration and strain are measured by the accelerometers C1 and C2 and the strain gauge C3 and measured. A transfer function is calculated from the acceleration signal, the distortion signal, and the vibration signal (step S3). An inverse transfer function is calculated from the transfer function calculated in step S3 (step S4).

Subsequent to step S4, the iterative calculation count n is initialized to an initial value = 0 (step S5), and an excitation signal is calculated (step S6). The operation of the first excitation signal in step S6 is, for example, Fourier transforming the target data for each iterative correction process in the block, and the inverse transfer function and the Fourier-transformed target data for the iterative correction process are multiplied to obtain a multiplication output. It is obtained by performing an inverse Fourier transform and multiplying the inverse Fourier transform output by a constant C (0 <C ≦ 1). This operation is performed over the target data for the iterative modification process of all blocks. Therefore, if the number of blocks is α and the number of target data for iterative correction process of each block is β, the number of excitation signals is αβ. Here, the constant C is common to all blocks.

The excitation signal obtained in step S6 excites all blocks (step S7). As a result of the vibration in step S7, the accelerometer C
1, the difference between each output of C2 and strain gauge C3 and the target data for each iterative correction process, that is, the error Er for each target data for each iterative correction process is calculated (step S
8) It is determined whether or not there is a block in which all the calculated error Er in the block is within the threshold value (step S9).

Error Er calculated in step S9
When it is determined that no block is within the threshold,
The correction value (= K · Er · inverse transfer function) is calculated (step S10). Here, K represents a coefficient, and (0 <
It is a value of K ≦ 1) and is arbitrarily selected in common for each block. Subsequent to step S10, the iterative calculation count n is incremented by 1 (step S11). Here, the coefficient K is set paying attention to a block having a large error Er.

Subsequent to step S11, the nth excitation signal is calculated by the calculation of (excitation signal of step S6 + correction value at the previous excitation) (step S11).
6) and then again from step S7. The excitation signal is sequentially corrected by repeating steps S6 to S11, the error Er decreases, and some blocks have the error Er calculated in step S9 within the threshold. When it is determined that there is a block in which all the error Er calculated in step S9 is within the threshold, the excitation signal at that time is stored in the block in which the calculated error Er is within the threshold. Be heard (step S1
2).

Subsequent to step S12, blocks in which the calculation error is within the threshold value are excluded from the iterative calculation (step S13), and all blocks are excluded until step S14.
Then, step S10 is executed. Therefore, when step S10 is executed after step S14, it is easy to set the correction value because there is a block for which the correction value need not be calculated, and the vibration in step S7 is not excluded in step S13. The calculation is performed on the remaining blocks, and the error Er is calculated on the target data for each iterative correction process of the remaining blocks as well. Therefore, the number of calculations and the number of vibrations are reduced, and the execution speed of this loop is substantially increased.

In the calculation of the correction value in step S10, the coefficient K is usually set by paying attention to a block having a large error Er as described above. Therefore, the error Er of the block having the target data for the iterative correction process with large fluctuations converges quickly, and the error Er of the block with the target data for the iterative correction process with gentle fluctuations converges with the iterative correction with large fluctuations. The error Er is faster than the convergence of the block having the process target data.
Will come within the threshold. As a result, the error Er
Is accelerated, the number of blocks in which the error Er is equal to or larger than the threshold value is reduced at a high speed, and the excitation signal over all blocks can be obtained quickly.

When it is determined in step S14 that all blocks have been excluded, the excitation signals are stored in all the blocks, and the excitation signals are connected in the order of blocks (step S15). Here, since the target data for the iterative correction process is set to "0" by the window function at the end of each block, the excitation signal for the end of each block becomes "0", and in this part Not excited.

The excitation signals are not concatenated by the window function in the overlap portion of each block.
The connection is made where the excitation signals coincide with each other within the range of the portion L in, that is, where there is no step in the excitation signal. By connecting in this way, the expansion of the time axis caused by blocking the target data disappears and the time axis of the excitation signal does not become long.

The actual vibration of the motorcycle 1 is simulated by applying the vibration signals obtained as described above to the vibration exciters 14, 15 and 16 and vibrating them. Excitation of the test vehicle will be described with reference to the road simulation apparatus shown in FIG.

Memory 12-embedded in controller 12
3 stores the excitation signal obtained by the procedure shown in FIG. 1, and the memory 12-
The first, second, and third vibration exciters 14, 15 and 16 are actuated based on the vibration signal stored in 3 and the piston rods 14a, 15a and 16a are driven to actually drive the motorcycle 1. Road load can be applied.

[0036]

As described above, according to the present invention, the target data for the iterative correction process divided into a plurality of blocks is obtained and calculated based on the output data obtained from the detector provided in the vehicle by the actual running of the vehicle. An initial excitation signal is calculated based on the inverse transfer function and the target signal for the iterative correction process, the excitation is performed by the calculated excitation signal, and the output of the detector by the excitation and the target data for the iterative correction process are generated. Error is calculated, and for a block in which the calculation error does not fall within the threshold value, a correction value consisting of the product of the calculation error and the inverse transfer function and the coefficient common to all blocks is added to the previous excitation signal to obtain a new value. As the excitation signal, the excitation signal is sequentially corrected until the calculation error reaches the threshold value, and the excitation is repeated with the corrected excitation signal. Therefore, the block in which the calculation error converges is excluded from the next excitation. thing It is the effect of convergence is early calculation error.

Further, the coefficient can be set by paying attention to a block having a large error, and the coefficient can be set easily, and the speed at which the calculation error converges within the threshold value is increased. Therefore, there is an effect that the efficiency of generating the excitation signal for the long target signal is improved.

Furthermore, according to the present invention, since the excitation and the correction calculation of the excitation signal can be performed in parallel, that is, simultaneously for different blocks, there is an effect that the generation efficiency of the excitation signal is further improved. is there.

Further, the first excitation signal is calculated for all blocks, the excitation signals of consecutive blocks are connected to each other at a level difference, and the same as the target signal generated based on the actual traveling data. A method is also conceivable in which, as a length excitation signal, excitation is performed by the excitation signal and correction is performed so that the error converges over all blocks. But,
In this case, a general road surface component with a long cycle of unevenness tends to have a large fluctuation width (amplitude), and a short cycle component tends to have a small amplitude, and a continuous block corresponds to an excitation signal corresponding to a large amplitude of the road surface. Regarding the connection of low frequency components of
Even if there is a slight phase shift between the two, a large step is generated in the connecting part, so the excitation signals are rarely completely coincident in the overlap part, and therefore the error of the low frequency component does not converge. Will increase. On the other hand, in the case of the present invention, the iterative correction process does not require the process of connecting the calculation excitation signals of the adjacent blocks at the excitation level other than zero,
It is easy to converge the error for the low frequency component.

Furthermore, in the case where the excitation signal having the same length as the above-mentioned target signal is applied to all the blocks and the correction is performed so that the error converges over all the blocks,
Even if the converged block is in the middle, it is not possible to omit the excitation of that block. On the other hand, in the case of the present invention, there is an effect that the vibration for the converged block can be omitted.

[Brief description of drawings]

FIG. 1 is a flow chart showing the method of the present invention.

FIG. 2 is a flow chart showing the method of the present invention.

FIG. 3 is a schematic diagram showing blocking of target data for an iterative correction process in the method of the present invention.

FIG. 4 is a schematic diagram showing one block of the target data for the blocked iterative correction process in the present invention.

FIG. 5 is a side view showing an example of a road simulation device for carrying out an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Motorcycle 2 ... Front axle 3 ... Front suspension 5 ... Rear axle 6 ... Rear fork 14, 15, 16 ... 1st, 2nd, 3rd vibrators C1, C2 ... Accelerometer C3 ... Strain gauge

Claims (4)

[Claims] 1. A control method of a road simulation apparatus for forcibly exciting a vehicle by an oscillating means so as to obtain an actual road surface load, wherein output data obtained from a detector provided on the vehicle by actual vehicle running. Is a number of data within a predetermined range and is divided into a plurality of blocks so as to overlap a neighboring block at an end over a predetermined number of data, and a first step of obtaining target data for the iterative correction process, A second step of calculating a transfer function based on an output of the detector when the vehicle is vibrated by a predetermined test signal by the road simulation device, and calculating an inverse transfer function from the calculated transfer function; The initial excitation signal is reproduced based on the inverse transfer function calculated in the process and the target data for the iterative correction process obtained in the first process. Then, the excitation is performed by the operation excitation signal, and the difference between the output of the detector due to the excitation and the target data for the iterative correction process is calculated as an error, and the operation error is calculated for the block whose operation error does not fall within the threshold value. And a correction value consisting of the product of the inverse transfer function and a predetermined coefficient set in advance, is added to the previous excitation signal to sequentially correct the excitation signal as a new excitation signal until the calculation error reaches the threshold value. And the excitation signals for the blocks in which all the calculation errors are within the threshold value are stored in sequence, and when this storage is completed for all blocks, the adjacent excitation signals in the overlapping part with the adjacent block are stored. And a fourth step of connecting the excitation signals at the same position as the total excitation signal, and controlling the road simulation apparatus. 2. The method according to claim 1, wherein the tip of each iterative-correction-process target data portion which overlaps with the iterative-correction-process target data of an adjacent block has a tip of "0", and A method for controlling a load simulation apparatus, wherein a multiplication process is performed with a window function that monotonically increases from "0" and the other end becomes "1". 3. The method according to claim 1, wherein the excitation signals of the respective blocks are connected to each other in an overlapping portion of the target data for the iterative correction process and in a portion other than the multiplication processing portion with the window function. A method for controlling a characteristic road simulation device. 4. The method of controlling a road simulation device according to claim 1, wherein the coefficient used for calculating the correction value is a value that is greater than 0 and less than 1.