CN110296848B - Pavement excitation output system and method based on measured data reconstruction - Google Patents

Abstract

The invention discloses a road excitation output system and method based on actual measurement data reconstruction in the technical field of vehicle dynamics. A road excitation signal generating unit is calculated by an inertia link correction type coherent transfer function calculation module and an inertia link correction type incoherent transfer function calculation module Module, non-stationary filter transfer function calculation module, first, second, third white noise module, first, second, third non-stationary filter transfer function module, first, second inertia link correction type incoherent transfer function The non-stationary filter model can be used for road excitation dynamics modeling when the road surface fluctuation index is not equal to 2, and can be easily used in real-time On-line generation of non-stationary road excitation signal generation enables the left and right wheel rut road excitation heads of the vehicle bench test bench to provide dual rut non-stationary road excitation consistent with the measured road surface calculated power spectrum and coherent transfer function.

Description

Pavement excitation output system and method based on measured data reconstruction

technical field

The invention belongs to the technical field of vehicle dynamics, and relates to dynamic simulation and bench test, in particular to an output system and method for generating dual-rut non-stationary road surface excitation of vehicles on-line in real time.

Background technique

Dynamic simulation and bench testing are important tools for automotive research and development, which can greatly reduce R&D costs and shorten R&D time. Road excitation is an unavoidable external disturbance that the car cannot avoid, and it has an important impact on the ride comfort, durability and rollover stability of the car. The modeling of pavement excitation is mainly divided into two aspects: single-track modeling and double-track modeling. For single wheel rut modeling, both the international standard ISO/TG 108/SC2N67 and the national standard GB 7031-2005 suggest that the pavement power spectral density (or power spectrum) G _q is expressed by formula (1):

In the formula, n ₀ is the reference pavement spatial frequency, and the recommended value of the national standard GB/T 7031-2005 is 0.1m ^-1 ; n is the pavement spatial frequency; G _q (n ₀ ) is the roughness coefficient under the reference pavement spatial frequency ; W is the road surface fluctuation index. If and only when W is 2, the smooth Gaussian model of the following equation (2) can be used to express the road surface excitation. At this time, MATLAB/Simulink software can be used to generate the road surface excitation in real time, which is very convenient to provide real-time road excitation for the real-time simulation of vehicle dynamics. Signals and real-time road excitation signals are provided for the road excitation exciter head of the vehicle bench test bench:

为q(I)的导数；I为道路走向长度；n_min为不平路面的下截止频率，国标GB/T 7031-2005的推荐取值为0.011m^-1；ω(I)为标准白噪声信号。where q(I) is the road excitation,

is the derivative of q(I); I is the length of the road; n _min is the lower cut-off frequency of the uneven road, the recommended value of the national standard GB/T 7031-2005 is 0.011m ^-1 ; ω(I) is the standard white noise signal .

However, the pavement fluctuation index W in the calculation formula of the pavement power spectral density G _q calculated according to the measured pavement excitation data is often not equal to 2, and it changes most of the time, that is, the actual pavement excitation is non-stationary. Therefore, in order to improve the modeling accuracy of single-track non-stationary pavement excitation, non-stationary Gaussian model, stationary Laplace model, non-stationary Laplace model, Gauss-Laplace mixture model, autoregressive (AR) model are proposed. ) model, autoregressive moving average (ARMA) model, inverse Fourier transform method, harmonic superposition method, wavelet analysis modeling method, etc. However, these methods all need to generate data offline in advance, and cannot directly use MATLAB/Simulink software to generate road excitation in real time, and have the disadvantages of computational workload and prior storage.

At present, the double-rut modeling is to fit the coherent transfer function model according to the coherent transfer function calculated from the actual detection of the left and right rut road surface excitation data, and then obtain the other one based on the single-rut road surface excitation signal. Rutted road surface excitation signal. Commonly used coherent transfer function models mainly include Ammon model, polyline model, exponential function model, quadratic model, isotropic single/multi-parameter model, rational factor reciprocal model, etc. At present, the most accurate fitting of the actual coherent transfer function is the Ammon model, which is expressed by the following formula (3):

In the formula, n is the road space frequency; ρ is the wheelbase; a is the wheelbase index; Ω ₀ is the reference space angular frequency; W is the road surface fluctuation index; p is the reference coefficient.

The other coherent transfer function models mentioned above have a common disadvantage with the Ammon model, that is, the model expressions all contain the pavement spatial frequency n, so it is impossible to use MATLAB/Simulink software to output the left and right rut pavement excitations in real time. Therefore, it is proposed to simulate and approximate the coherent transfer function by using the transfer function with the same number of upper and lower terms in the following equation (4). This model requires many parameters to be fitted, and positive points are easily formed during the fitting process. Another rut road surface excitation obtained by this transfer function, the calculated left and right rut road surface excitation signals can not meet the specified power spectrum and coherent transfer function requirements:

In the formula, S=j2πn, j is a unit imaginary number; λ ₀ , λ ₁ , ..., λ _k , η ₀ , η ₁ , ..., η _k are all model fitting parameters.

SUMMARY OF THE INVENTION

Aiming at the problem that the calculated power spectrum of the existing measured road surface does not match the coherent transfer function, and the coherent transfer function model and the non-stationary road excitation model cannot generate the dual-track non-stationary road excitation online in real time, the invention provides a method based on the measured data. The pavement excitation output system and method are constructed to realize the real-time generation of dual-track non-stationary pavement excitation whose calculated power spectrum of the measured pavement is consistent with the coherent transfer function.

The technical scheme adopted by the road surface excitation output system based on actual measurement data reconstruction according to the present invention is: including a road surface roughness acquisition system and a vehicle road simulation test system, the road surface roughness acquisition system is composed of a multi-functional laser road detector and a GPS The receiver is composed. The output end of the GPS receiver is connected to the input end of the multi-function laser road detector. The GPS receiver collects the longitudinal coordinates of the road. R and output the measured data L ₁ (I) and R ₁ (I) of the left and right rut road surface roughness; the vehicle road simulation test system consists of a control system, a left exciter head, a right exciter head, and the control system is excited by the road surface. The signal generating unit, the left exciter head servo control unit and the right exciter head servo control unit are composed. The output end of the multi-function laser road detector is connected to the input end of the road excitation signal generation unit, and the output end of the road surface excitation signal generation unit is respectively connected to The input end of the left exciter head servo control unit and the right exciter head servo control unit, the output end of the left exciter head servo control unit is connected to the input end of the left exciter head, and the output of the left exciter head is the simulated road excitation L ( t), the output end of the right exciter head servo control unit is connected to the input end of the right exciter head, and the right exciter head outputs the simulated road surface excitation R(t).

The road excitation signal generating unit is composed of an inertia link correction type coherent transfer function calculation module, an inertia link correction type incoherent transfer function calculation module, a non-stationary filter transfer function calculation module, a first, second, third white noise module, The first, second and third non-stationary filter transfer function modules, the first and second inertial link correction type incoherent transfer function modules, the inertia link correction type coherent transfer function module and the first and second summation modules are composed; The output terminals of the multi-function laser path detector described above are respectively connected to the input terminals of the inertia link correction type coherent transfer function calculation module, the inertia link correction type incoherent transfer function calculation module, the non-stationary filter transfer function calculation module, and the inertia link correction type coherent transfer function calculation module. The output end of the transfer function calculation module is connected to an input end of the inertia link correction type coherent transfer function module, and the output end of the inertia link correction type incoherent transfer function module is respectively connected to the first inertia link correction type incoherent transfer function module and the second inertia link correction type incoherent transfer function module. Each input end of the inertia link correction type incoherent transfer function module, and the output end of the non-stationary filter transfer function calculation module are respectively connected to the first non-stationary filter transfer function module, the second non-stationary filter transfer function module and the third non-stationary filter transfer function module. The respective input ends of the stationary filter transfer function module; the output end of the first white noise module is connected to the first non-stationary filter transfer function module, the output end of the second white noise module is connected to the second non-stationary filter transfer function module, the first The output end of the three-white noise module is connected to the third non-stationary filter transfer function module, the output end of the first non-stationary filter transfer function module is connected to the other input end of the first inertia link correction type incoherent transfer function module, and the second non-stationary filter transfer function module The output terminal of the filter transfer function module is connected to the other input terminal of the inertial link correction type coherent transfer function module, and the output terminal of the third non-stationary filter transfer function module is connected to the other input terminal of the second inertia link correction type incoherent transfer function module. , the output terminals of the first inertial link correction type incoherent transfer function module and the inertia link correction type coherent transfer function module are connected to the input terminal of the first summation module, and the output terminal of the first summation module is connected to the left excitation head servo control The input end of the unit, the output end of the second inertia link correction type incoherent transfer function module and the inertia link correction type coherent transfer function module are all connected to the input end of the second summation module, and the output end of the second summation module is connected to the right excitation The input terminal of the vibration head servo control unit.

The technical scheme adopted by the road surface excitation output method of the road surface excitation output system reconstructed based on the measured data according to the present invention is that it includes the following steps:

Step A: The first inertia link correction type coherent transfer function calculation module processes the measured data L ₁ (I) and R ₁ (I) of the left and right rut road surface roughness to obtain the inertia link correction type coherent transfer function H ₁ ( S), input H ₁ (S) into the inertia link correction type coherent transfer function module; the inertia link correction type incoherent transfer function calculation module calculates the measured data L ₁ (I) and R ₁ of the left and right rut road surface roughness (1) carry out processing to obtain the inertial link correction type incoherent transfer function H ₂ (S), and input H ₂ (S) to the first inertia link correction type incoherent transfer function module and the second inertia link correction type incoherent transfer function module In the function module, the non-stationary filter transfer function calculation module processes the measured data L ₁ (I) and R ₁ (I) of the left and right rut road surface roughness to obtain the non-stationary filter transfer function H ₀ (S), The transfer function H ₀ (S) is respectively input into the first, second and third non-stationary filter transfer function modules;

Step B: The first white noise module generates white noise ω ₁ (t) and inputs it to the first non-stationary filter transfer function module. The output of the first non-stationary filter transfer function module is the non-stationary road excitation q ₁ (t) and is input to the first non-stationary filter transfer function module. In the first inertial link correction type incoherent transfer function module; the second white noise module generates white noise ω ₂ (t) and inputs it to the second non-stationary filter transfer function module, the output of the second non-stationary filter transfer function module is non-stationary The road excitation q ₂ (t) is input to the inertia link correction type coherent transfer function module; the third white noise module generates white noise ω ₃ (t) and inputs it to the third non-stationary filter transfer function module, the third non-stationary filter The output of the transfer function module is the non-stationary road excitation q3(t) and input to the second inertial link correction type incoherent transfer function module:

Step C: The first inertial link correction type incoherent transfer function module processes the non-stationary road surface excitation q ₁ (t) to obtain the left wheel rutting disturbance road surface excitation qLi(t) and inputs it into the first summation module; the inertia link correction type The coherent transfer function module processes the input non-stationary road excitation q ₂ (t) and the inertial link correction type coherent transfer function H ₁ (S) to obtain the remaining road excitation q _c (t), which are respectively input to the first summation module and In the second summation module, the second inertia link correction type incoherent transfer function module processes the input non-stationary road excitation q ₃ (t) signal to obtain the right wheel rutting disturbance road excitation q _Ri (t), which is input to the second summation module. In the summation module;

Step D: The first summation module sums the input road excitations q _Li (t) and q _c (t) to obtain the left-wheel rut road excitation L ₁ (t) and inputs it into the left exciter head servo control unit, the second The summation module sums the input road excitations q _Ri (t) and q _c (t) to obtain the right wheel rut road excitation R ₁ (t) and inputs it into the right exciter head servo control unit;

Step E: The servo control unit _of the left and right exciters controls the left and right exciters to output the simulated road excitation L( _t ) and R( t).

After the present invention adopts the above-mentioned technical scheme, the beneficial effects it has are:

1. Using the present invention, the left and right wheel rut road excitation excitation heads of the vehicle bench test bench can provide double rut non-stationary road excitation consistent with the measured road surface calculated power spectrum and coherent transfer function.

2. The non-stationary filter model provided by the present invention can be used for the dynamic modeling of road surface excitation when the road surface fluctuation index is not equal to 2, and can be conveniently used for real-time online generation of non-stationary road excitation signal generation.

3. The left and right wheel rut non-stationary road surface excitation data generated by the present invention has less computational workload and high precision.

Description of drawings

Fig. 1 is the system block diagram that realizes the present invention;

FIG. 2 is a structural block diagram of the road excitation signal generating unit in FIG. 1 .

Detailed ways

Referring to FIG. 1, the road surface excitation output system reconstructed based on the measured data of the present invention adopts the road road surface roughness acquisition system to measure the left and right rut road surface roughness L ₁ (I), R ₁ (I) data of the vehicle. L ₁ (I) and R ₁ (I) are input to the vehicle road simulation test system, and are processed by the vehicle road simulation test system to generate simulated road excitation L(t) and R(t). Among them, the road surface roughness acquisition system is composed of a multi-function laser road detector and a GPS receiver. The output end of the GPS receiver is connected to the input end of the multi-function laser road detector, and the output end of the multi-function laser road detector is connected to the vehicle road. Simulation test system. The multi-function laser road detector and GPS receiver are both arranged on the top beam of the car. The GPS receiver obtains the road longitudinal coordinate I of the collection point on the road length at a certain length interval, and inputs the road longitudinal coordinate I to the multi-function laser. road tester. The multi-function laser road detector actually measures the excitation heights of the left and right rut road surfaces at the collection point, which are the excitation height L of the left rut road and the excitation height R of the right rut road respectively. The multi-function laser road detector combines the measured heights L and R of the road surface excitation with the road longitudinal coordinate I, and fuses the measured data L ₁ (I) and R ₁ (I) of the left and right rut road surface roughness in the road space domain. , and then sent to the vehicle road simulation test system.

The vehicle road simulation test system is composed of a control system, a left exciter head and a right exciter head, wherein the control system is composed of a road excitation signal generating unit, a left exciter head servo control unit, and a right exciter head servo control unit. . The output end of the multifunctional laser road detector is connected to the input end of the road excitation signal generating unit, and the output end of the road surface excitation signal generating unit is respectively connected to the input end of the left exciter head servo control unit and the right exciter head servo control unit. The output end of the left exciter head servo control unit is connected to the input end of the left exciter head, the left exciter head outputs the simulated road excitation L(t), and the output end of the right exciter head servo control unit is connected to the right exciter head. At the input end, the output of the right exciter head is the simulated road excitation R(t).

Referring to Fig. 2, the road excitation signal generating unit is composed of an inertia link correction type coherent transfer function calculation module 12, an inertia link correction type incoherent transfer function calculation module 13, a non-stationary filter transfer function calculation module 14, the first, second, third White noise modules 1, 2, 3, first, second, and third non-stationary filter transfer function modules 4, 5, 6, first and second inertial link correction type incoherent transfer function modules 7, 9, inertial link correction It consists of a coherent transfer function module 8 and first and second summation modules 10 and 11.

Among them, the output end of the multi-function laser path detector is respectively connected to the input end of the inertia link correction type coherent transfer function calculation module 12, the inertia link correction type incoherent transfer function calculation module 13, and the non-stationary filter transfer function calculation module 14. , the measured data L ₁ (I) and R ₁ (I) of the road surface roughness of the right rut are input into the inertia link correction type coherent transfer function calculation module 12, the inertia link correction type incoherent transfer function calculation module 13 and the non-stationary filter transfer function calculation module 14. The output end of the inertia link correction type coherent transfer function calculation module 12 is connected to an input end of the inertia link correction type coherent transfer function module 8, and the output ends of the inertia link correction type incoherent transfer function calculation module 13 are respectively connected to the first inertia link correction type. One input terminal of the incoherent transfer function module 7 and the second inertial link correction type incoherent transfer function module 9 respectively. The output terminals of the non-stationary filter transfer function calculation module 14 are respectively connected to the respective input terminals of the first non-stationary filter transfer function module 4 , the second non-stationary filter transfer function module 5 and the third non-stationary filter transfer function module 6 . The output terminals of the three independent white noise modules 1, 2, and 3 are respectively connected to the other input terminals of a corresponding non-stationary filter transfer function module 4, 5, and 6, that is, the output terminal of the first white noise module 1 is connected to the third input terminal. A non-stationary filter transfer function module 4, the output terminal of the second white noise module 2 is connected to the second non-stationary filter transfer function module 5, and the output terminal of the third white noise module 3 is connected to the third non-stationary filter transfer function module 6. The output end of the first non-stationary filter transfer function module 4 is connected to the other input end of the first inertia link correction type incoherent transfer function module 7, and the output end of the second non-stationary filter transfer function module 5 is connected to the inertia link correction type coherent transfer function module. The other input end of the function module 8 and the output end of the third non-stationary filter transfer function module 6 are connected to the other input end of the second inertia link correction type incoherent transfer function module 9 . The output terminals of the first inertial link correction type incoherent transfer function module 7 and the inertia link correction type coherent transfer function module 8 are both connected to the input terminal of the first summation module 10, and the output terminal of the first summation module 10 is connected to the left excitation Input of the head servo control unit. The outputs of the second inertial link correction type incoherent transfer function module 9 and the inertial link correction type coherent transfer function module 8 are both connected to the input terminal of the second summing module 11 , and the output terminal of the second summing module 11 is connected to the right excitation Input of the head servo control unit.

Wherein, the first inertia link correction type coherent transfer function calculation module 12 calculates and processes the received actual measurements L ₁ (I) and R ₁ (I) to obtain the inertia link correction type coherent transfer function H ₁ (S), ₁ (S) is input into the inertia link correction type coherent transfer function module 8 to complete the construction of the inertia link correction type coherent transfer function module 8 . The inertial link correction type incoherent transfer function calculation module 13 calculates and processes the received measured data L ₁ (I) and R ₁ (I) to obtain the inertia link correction type incoherent transfer function H ₂ (S), and the H ₂ (S) Input into the first inertial link correction type incoherent transfer function module 7 and the second inertial link correction type incoherent transfer function module 9 to complete the first inertial link correction type incoherent transfer function module 7 and the second inertial link. Construction of Corrected Incoherent Transfer Function Module 9. The non-stationary filter transfer function calculation module 14 performs calculation processing on the received measured data L ₁ (I) and R ₁ (I) to obtain the non-stationary filter transfer function H ₀ (S), and the filter transfer function H ₀ (S) Input to the first, second, and third non-stationary filter transfer function modules 4, 5, and 6, respectively, to complete the construction of the first, second, and third non-stationary filter transfer function modules 4, 5, and 6.

Wherein, the first white noise module 1 generates white noise ω ₁ (t), and the white noise ω ₁ (t) is input to the first non-stationary filter transfer function module 4, and the output of the first non-stationary filter transfer function module 4 is non-stationary The road excitation signal q ₁ (t) and the non-stationary road excitation signal q ₁ (t) are input to the first inertial link correction type incoherent transfer function module 7 . The second white noise module 2 generates white noise ω ₂ (t), and inputs the white noise ω ₂ (t) to the second non-stationary filter transfer function module 5, and the output of the second non-stationary filter transfer function module 5 is non-stationary road excitation The signal q ₂ (t) and the non-stationary road excitation signal q ₂ (t) are input to the inertial link correction type coherent transfer function module 8 . The third white noise module 3 generates white noise ω ₃ (t), and the white noise ω ₃ (t) is input to the third non-stationary filter transfer function module 6, and the output of the third non-stationary filter transfer function module 6 is non-stationary road excitation The signal q ₃ (t) and the non-stationary road excitation signal q ₃ (t) are input to the second inertial link correction type incoherent transfer function module 9 .

The first inertia link correction type incoherent transfer function module 7 processes the input non-stationary road excitation q ₁ (t) signal to obtain the left wheel rutting disturbance road excitation q _Li (t) signal, and the q _Li (t) signal input into the first summation module 10 . The inertia link correction type coherent transfer function module 8 processes the input non-stationary road excitation q ₂ (t) signal and the inertia link correction type coherent transfer function H ₁ (S) to obtain the remaining road excitation q _c (t) signal, and The q _c (t) signal is input to the first summation module 10 and the second summation module 11, respectively. The second inertial link correction type incoherent transfer function module 9 processes the input non-stationary road excitation q ₃ (t) signal to obtain the right wheel rutting disturbance road excitation q _Ri (t) signal, and converts the q _Ri (t) The signal is input into the second summation block 11 .

The first summation module 10 sums up the input road excitations q _Li (t) and q _c (t) to obtain the left-wheel rut road excitation L ₁ (t), and the left-wheel rut road excitation L ₁ (t) is input to the left-wheel rut road excitation L 1 (t). Vibrating head servo control unit. The second summation module 11 sums up the input road excitations q _Ri (t) and q _c (t) to obtain the right wheel rut road excitation R ₁ (t), and the right wheel rut road excitation R ₁ (t) is input to In the right exciter head servo control unit.

The left and right exciter heads are respectively fixed on the upper end of the piston rod of the hydraulic cylinder of the vertically upward vehicle, and the left and right exciter head servo control units are controlled according to the excitation L ₁ (t) and R ₁ (t) of the left and right wheel rutting road surfaces. The left and right excitation heads output different simulated road excitation L(t) and R(t) in real time to simulate road excitation.

Referring to Figure 1-2, before the vehicle road simulation test system works, first use the road surface roughness acquisition system to measure the roughness data of the left and right rut road surfaces at least 2 kilometers long, and calculate the excitation self-power of the left and right rut road surfaces. spectral density and coherent transfer function, and then construct a non-stationary filter transfer function module, an inertial link-corrected coherent transfer function module, an inertial link-corrected non-inertial link-corrected coherent transfer function module, and then based on the vehicle speed v( m/s) to determine the input parameters of the white noise module. When the vehicle road simulation test system is working, the left and right wheels of the test vehicle are respectively fixed on the corresponding left and right exciter heads, and the left and right exciter head servo control units are based on the left and right wheel rutting road surfaces output by the summation module. The excitation L ₁ (t) and R ₁ (t) control the left and right piston rods to output different heights in real time, that is, to simulate the road excitation L(t) and R(t). The simulated road excitation input corresponding to the left and right rut road surface excitation real-time signals. The specific process is as follows:

为采样间隔，其中n_max为不平路面上的截止频率，国标GB/T 7031-2005的推荐取值为2.83m^-1，确定各路面不平度采集点的道路纵向坐标I，并输入至多功能激光路检测仪，多功能激光路检测仪在道路坐标点实测左轮辙路面激励高度L和右轮辙路面激励高度R，采集完成后生成左、右轮辙路面不平度L₁(I)、R₁(I)，然后发送至控制系统。Step 1: Use the road surface roughness acquisition system to measure the road surface roughness, and measure the road surface roughness data of left and right wheel ruts at least 2 kilometers long. On the longitudinal coordinate I of the measured road, the GPS receiver uses twice the reciprocal of the cutoff frequency on the uneven road

is the sampling interval, where n _max is the cut-off frequency on the uneven road, the recommended value of the national standard GB/T 7031-2005 is 2.83m ^-1 , determine the road longitudinal coordinate I of each road roughness collection point, and input it to the multi-function laser The road detector and the multi-function laser road detector actually measure the excitation height L of the left rut road and the excitation height R of the right rut road at the road coordinate points, and generate the left and right rut road surface roughness L ₁ (I), R ₁ (I), and then sent to the control system.

Step 2: The inertia link correction type coherent transfer function calculation module 12 and the inertia link correction type incoherent transfer function calculation module 13 process the left and right rut road surface roughness L ₁ (I), R ₁ (I), using Matlab The mscohere() function provided by the software first obtains the coherence function square vector Coh2 _LR according to the formula (5), and then obtains the coherence function Coh _LR in the spatial domain of L ₁ (I) and R ₁ (I) according to the formula (6). , Coh _LR is a one-to-one correspondence with the road surface spatial frequency vector n _R .

[Coh2 _LR n _R ]=mscohere(L ₁ (I),R ₁ (I), 256, [], 1024, 2n _max ) (5)

Among them, Coh2 _LR is the square vector of the coherence function vector Coh _LR ; n _R is the pavement space frequency vector corresponding to the Coh _LR data; [] means to use the default value.

Then, the inertia link correction type coherent transfer function calculation module 12 uses the lsqcurvefit() tool provided by the MATLAB software to fit the following equation (7) to obtain the fitting parameters α ₀ , α ₁ , α ₂ , β ₀ , β ₁ and β _2. When fitting, iterate through each value in the vector n _R :

Among them, j is the unit imaginary number; α ₀ , α ₁ , α ₂ , β ₀ , β ₁ and β ₂ are all non-negative fitting parameters; n is the road space frequency.

Different from the fitting method of the inertia link correction type coherent transfer function calculation module 12, the inertia link correction type incoherent transfer function calculation module 13 uses the lsqcurvefit() tool provided by the MATLAB software to fit the following equation (8). Combine the values of the parameters ψ ₀ , ψ ₁ , ψ ₂ , ξ ₀ , ξ ₁ and ξ ₂ , and take each value in the vector n _R during fitting:

Among them, ψ ₀ , ψ ₁ , ψ ₂ , ξ ₀ , ξ ₁ and ξ ₂ are all non-negative fitting parameters.

The inertia link correction type coherent transfer function calculation module 12 constructs the transfer function of the inertia link correction type coherent transfer function model according to the fitting parameters α ₀ , α ₁ , α ₂ , β ₀ , β ₁ , β ₂ as follows: H ₁ (S).

where S is the Laplace operator.

The inertia link correction type incoherent transfer function calculation module 13 constructs the inertia link correction type incoherent transfer function model according to the fitting parameters ψ ₀ , ψ ₁ , ψ ₂ , ξ ₀ , ξ ₁ , ξ ₂ as follows: Transfer function H ₂ (S).

和

为惯性环节趋势项，描述惯性环节校正型相干传递函数模型和惯性环节校正型不相关函数模型的大致形态；

和

为拟合精度校正项，在趋势项确定相干传递函数模型和不相关函数模型大致形态基础上，根据具体数值的不同进行模型精度校正来提高建模精度，校正项越多拟合精度越高，校正项数可根据实际拟合精度要求进行增减。In formula (9) and formula (10),

and

is the inertial link trend term, describing the approximate shape of the inertial link-corrected coherent transfer function model and the inertial link-corrected uncorrelated function model;

and

In order to fit the accuracy correction term, on the basis of determining the approximate shape of the coherent transfer function model and the uncorrelated function model by the trend term, the model accuracy is corrected according to the specific values to improve the modeling accuracy. The more correction terms, the higher the fitting accuracy. The number of correction items can be increased or decreased according to the actual fitting accuracy requirements.

Step 3: Simultaneously with step 2, the non-stationary filter transfer function calculation module 14 processes the measured data L ₁ (I) and R ₁ (I) of the left and right rut road surface excitation, and uses the pwelch (I) provided by the MATLAB software. ) function to obtain the self-power spectral densities GL and GR in the spatial domain of _{L 1} (I) and _{R 1} (I) according to formulas (11) and (12), respectively, _GL and _GR are both related to the road surface space Frequency vector n _R one-to-one correspondence vector:

[G _L n _R ]=pwelch(L ₁ (I),1024,[],[],2n _max ) (11)

[G _R n _R ]=pwelch(R ₁ (I),1024,[],[],2n _max ) (12)

Then, the non-stationary filter transfer function calculation module 14 uses the mean() function provided by the MATLAB software to obtain the estimated road excitation coefficient that needs to generate road excitation according to formula (13).

In the formula, n is the spatial frequency of the road surface, and each value in the vector n _R is taken during fitting.

Then, the non-stationary filter transfer function calculation module 14 uses the lsqcurvefit() tool provided by the MATLAB software to obtain fitting parameters χ ₀ , χ ₁ , χ ₂ , χ ₃ , μ ₁ , μ ₂ and μ by fitting according to equation (13). The value of ₃ :

In the formula, _ns is the frequency point with the largest error after the initial correction; _{χ 0} , χ ₁ , χ ₂ , χ ₃ , μ ₁ , μ ₂ and μ ₃ are all fitting parameters greater than 0; lower cutoff frequency.

作为车辆道路模拟试验系统左右轮辙路面激励激振头提供实时的时域内预估路面激励系数，并按下式(14)构建非平稳滤波传递函数H₀(S)：When the vehicle speed to be simulated by the vehicle road simulation test system is vm/s, the

As the vehicle road simulation test system, the left and right rut road surface excitation exciters provide real-time estimated road excitation coefficients in the time domain, and the non-stationary filter transfer function H ₀ (S) is constructed as follows:

为由式(13)求取出的需要生成路面激励的预估路面激励系数；

为基准滤波项，它对应路面波动指数W等于2，

为路面波动指数初次修正项，χ₁＞μ₁对应W＜2，

是针对初次修正后误差最大频率点n_s的特征频率点修正项，χ₀为预估不平度系数修正项，特征频率点修正项越多拟合精度越高，它的项数可根据实际拟合精度要求进行增减。Among them, v is the speed of the car;

is the estimated pavement excitation coefficient that needs to generate pavement excitation obtained from equation (13);

is the reference filtering term, which corresponds to the road surface fluctuation index W equal to 2,

is the first correction term of the road surface fluctuation index, χ ₁ >μ ₁ corresponds to W < 2,

It is the feature frequency point correction term for the maximum error frequency point _ns after the initial correction, χ ₀ is the estimated roughness coefficient correction term, the more feature frequency point correction terms, the higher the fitting accuracy, and the number of its terms can be adjusted according to the actual fit. Increase or decrease according to the accuracy requirements.

Step 4: Input the transfer function H ₁ (S) in step 2 to the inertial link correction type coherent transfer function module 8 , and input the transfer function H ₂ (S) to the first inertia link correction type incoherent transfer function module 7 respectively In the second inertia link correction type incoherent transfer function module 9, the non-stationary filter transfer function H ₀ (S) in step 3 is input into the three non-stationary filter transfer function modules 4 , 5 and 6 .

t为时间变量，种子分别设定为23341、23343和23347，此时，按采用频率2vn_max计算ω_i(t)(i＝1,2,3)在[0 vn_max]频率范围内的功率谱密度G_ωi等于2。白噪声信号ω₁(t)输入至第一非平稳滤波传递函数模块4中，白噪声信号ω₂(t)输入至第二非平稳滤波传递函数模块5中，白噪声信号ω₃(t)输入至第三非平稳滤波传递函数模块6中。Three independent white noise signals ω ₁ (t), ω ₂ (t) and ω ₃ (t) are generated by the three white noise modules 1, 2 and 3 respectively. Spectral value and sampling time are set to 1 and

t is a time variable, and the seeds are set to 23341, 23343 and 23347 respectively. At this time, the power of ω _i (t) (i=1,2,3) in the frequency range of [0 vn _max ] is calculated according to the frequency 2vn _max The spectral density _Gωi is equal to 2. The white noise signal ω ₁ (t) is input into the first non-stationary filter transfer function module 4, the white noise signal ω ₂ (t) is input into the second non-stationary filter transfer function module 5, the white noise signal ω ₃ (t) Input to the third non-stationary filter transfer function module 6 .

然后对

和H₀(S)的乘积进行傅里叶逆变换，得到非平稳路面激励

其中

与

分别为傅里叶变换运算符和傅里叶逆换变换运算符，计算时拉普拉斯算子S＝j2πn。The first non-stationary filter transfer function module 4 processes the input white noise signal ω ₁ (t) to obtain a non-stationary road excitation signal q ₁ (t). The second non-stationary filter transfer function module 5 processes the input white noise signal ω ₂ (t) to obtain a non-stationary road excitation signal q ₂ (t). The third non-stationary filter transfer function module 6 processes the input white noise signal ω ₃ (t) to obtain a non-stationary road excitation signal q ₃ (t). The three non-stationary filter transfer function modules 4, 5, and 6 process the input signals in the same way. Taking the first non-stationary filter transfer function module 4 as an example, the specific process is: first, the white noise signal ω ₁ (t) is processed. Fourier transform to get

then right

The product of and H ₀ (S) is inverse Fourier transformed to obtain the non-stationary road excitation

in

and

They are the Fourier transform operator and the inverse Fourier transform operator, respectively, and the Laplace operator S=j2πn during calculation.

惯性环节校正型相干传递函数模块8对输入的非平稳路面激励信号q₂(t)得到剩余路面激励q_c(t)信号，

第二惯性环节校正型不相干传递函数模块9对输入的非平稳路面激励q₃(t)进行处理，得到右轮辙扰动路面激励q_Ri(t)，

The first inertia link correction type incoherent transfer function module 7 processes the input non-stationary road excitation q ₁ (t) signal to obtain the left wheel rutting disturbance road excitation q _Li (t) signal,

The inertial link correction type coherent transfer function module 8 obtains the remaining road excitation q _c (t) signal from the input non-stationary road excitation signal q ₂ (t),

The second inertia link correction type incoherent transfer function module 9 processes the input non-stationary road excitation q ₃ (t) to obtain the right wheel rutting disturbance road excitation q _Ri (t),

The first inertia link correction type incoherent transfer function module 7 and the inertia link correction type coherent transfer function module 8 respectively output the left wheel rutting disturbance road excitation q _Li (t) and the remaining road excitation q _c (t) to the first summation module 10 , the first summation module 10 calculates the rutted road surface excitation L ₁ (t) according to the formula L ₁ (t)=q _Li (t)+q _c (t). The second inertia link correction type incoherent transfer function module 9 and the inertia link correction type coherent transfer function module 8 respectively output the right wheel rutting disturbance road excitation q _Ri (t) and the remaining road excitation q _c (t) to the second summation module In 11, the second summation module 11 calculates the left-wheel rutted road surface excitation R ₁ (t) according to the formula R ₁ (t)=q _Ri (t)+q _c (t).

Step 5: The exciter head servo control unit receives the left and right rut road surface excitations L ₁ (t) and R ₁ (t) generated in step 4, and drives the corresponding left and right exciters respectively. Road excitation and left and right rut road excitation determined by simulated vehicle speed. The left and right wheels of the test vehicle are respectively fixed on the corresponding left and right exciter heads, and the left and right exciter head servo control units receive the left and right wheel rutting road surface excitations L ₁ (t) and R ₁ (t) in step 4, Control the left and right piston rods to output different heights in real time. At this time, the values of the actual simulated road surface excitation L(t) and R(t) are respectively equal to the left-wheel rutted road surface excitation signal L ₁ (t) and the right-wheel rutted road surface excitation signal R ₁ (t).

In the present invention, the complex expressions of the left-wheel rut road excitation signal L ₁ (t) and the right-wheel rut road road excitation signal R ₁ (t) in the time domain are shown in the following equations (15) and (16) respectively. :

L ₁ (j2πn)=H ₂ (j2πn)q ₁ (j2πn)+H ₁ (j2πn)q ₂ (j2πn) (15)

R ₁ (j2πn)=H ₂ (j2πn)q ₃ (j2πn)+H ₁ (j2πn)q ₂ (j2πn) (16)

的数值与路面激励空间域内相干传递函数Coh_LR相等，但

和

对应的频率向量由n_R在车速v的作用下转变成了vn_R。Since the specified value of the coherent transfer function in the time domain is

The value of is equal to the coherent transfer function Coh _LR in the pavement excitation space domain, but

and

The corresponding frequency vector is transformed from n _R to vn _R under the action of the vehicle speed v.

和相干传递函数

分别由式(17)、(18)和(19)表示。Self-power spectral density of left and right rutted road excitation signals L ₁ (t) and R ₁ (t) in time domain

and the coherent transfer function

are represented by equations (17), (18) and (19), respectively.

和

分别为时域内L₁(t)、R₁(t)、q₁(t)、q₂(t)和q₃(t)的自功率谱密度；

和

分别为时域内q₁(t)、q₂(t)和q₃(t)的互功率谱密度；

和

分别为时域内L₁(t)和R₁(t)的互功率谱密度。in,

and

are the self-power spectral densities of L ₁ (t), R ₁ (t), q ₁ (t), q ₂ (t) and q ₃ (t) in the time domain, respectively;

and

are the cross-power spectral densities of q ₁ (t), q ₂ (t) and q ₃ (t) in the time domain, respectively;

and

are the cross-power spectral densities of L ₁ (t) and R ₁ (t) in the time domain, respectively.

Since the self-power spectral densities of q ₁ (t), q ₂ (t) and q ₃ (t) are equal, they can be known from q _i (t)=H ₀ ω _i (t) (i=1,2,3) Since the power spectral density is

In the formula, G _ωi is the power spectral density of the frequency-octave half-unit white noise signal ω _i (t) in the time domain, which is equal to 2.

Putting (13) and (14) into equation (21), we have:

和

均等于零，式(17)、(18)和(19)可以化简为：Since q ₁ (t), q ₂ (t) and q ₃ (t) are independent of each other, so

and

are equal to zero, equations (17), (18) and (19) can be simplified as:

相吻合，式(24)表明使用本发明提供的方法可以使实时生成左右轮辙路面激励的相干传递函数与模拟汽车以速度v行驶在步骤1中实测路面上的相干传递函数模型

相吻合。Since the values of the actual simulated road excitation L(t) and R(t) are respectively equal to the left-wheel rutted road excitation signals L ₁ (t) and R ₁ (t), equations (22) and (23) indicate that the use of the present invention provides The method can make the product of the real-time generated power spectral density of the left and right rut road surface excitation and the power spectral density of the simulated car driving at the speed v on the measured road surface in step 1.

Consistent, formula (24) shows that using the method provided by the present invention can make the real-time generation of the coherent transfer function of the left and right rut road excitation and the coherent transfer function model of the simulated car driving at the speed v on the road measured in step 1.

match.

Claims (5)

1. The utility model provides a road surface excitation output system based on measured data reconsitution, including road surface roughness collection system and vehicle road analogue test system, road surface roughness collection system comprises multi-functional laser way detector and GPS receiver, the input of multi-functional laser way detector is connected to the output of GPS receiver, the GPS receiver gathers road longitudinal coordinate, multi-functional laser way detector is at the height L, R of the left, right wheel rut road surface excitation of collection point actual measurement, and output left, right wheel rut road surface roughness measured data L₁(I) And R₁(I) (ii) a The vehicle road simulation test system comprises a control system, a left excitation head and a right excitation head, wherein the control system comprises a road excitation signal generating unit, a left excitation head servo control unit and a right excitation head servo control unit, the output end of the multifunctional laser path detector is connected with the input end of the road excitation signal generating unit, the output end of the road excitation signal generating unit is respectively connected with the input ends of the left excitation head servo control unit and the right excitation head servo control unit, the output end of the left excitation head servo control unit is connected with the input end of the left excitation head, the left excitation head outputs a simulated road surface excitation L (t), the output end of the right excitation head servo control unit is connected with the input end of the right excitation head, and the right excitation head outputs a simulated road surface excitation R (t), and is characterized in that: the road surface excitation signal generating unit is corrected by an inertia link to form a coherent transfer functionThe device comprises a calculation module (12), an inertial link correction type incoherent transfer function calculation module (13), a non-stationary filtering transfer function calculation module (14), a first white noise module, a second white noise module, a third white noise module (1, 2,3), a first non-stationary filtering transfer function module, a second non-stationary filtering transfer function module, a third non-stationary filtering transfer function module (4, 5, 6), a first inertial link correction type incoherent transfer function module, a second inertial link correction type incoherent transfer function module (7, 9), an inertial link correction type coherent transfer function module (8) and a first summation module (10, 11); the output end of the multifunctional laser path detector is respectively connected with the input ends of an inertia link correction type coherent transfer function calculation module (12), an inertia link correction type incoherent transfer function calculation module (13) and a nonstationary filtering transfer function calculation module (14), the output end of the inertia link correction type coherent transfer function calculation module (12) is connected with one input end of an inertia link correction type coherent transfer function module (8), the output end of the inertia link correction type incoherent transfer function calculation module (13) is respectively connected with 1 input end of a first inertia link correction type incoherent transfer function module (7) and 1 input end of a second inertia link correction type incoherent transfer function module (9), and the output end of the nonstationary filtering transfer function calculation module (14) is respectively connected with the first nonstationary filtering transfer function module (4), 1 input of each of a second non-stationary filter transfer function module (5) and a third non-stationary filter transfer function module (6); the output end of the first white noise module (1) is connected with a first non-stationary filtering transfer function module (4), the output end of the second white noise module (2) is connected with a second non-stationary filtering transfer function module (5), the output end of the third white noise module (3) is connected with a third non-stationary filtering transfer function module (6), the output end of the first non-stationary filtering transfer function module (4) is connected with the other input end of the first inertia link correction type incoherent transfer function module (7), the output end of the second non-stationary filtering transfer function module (5) is connected with the other input end of the inertia link correction type coherent transfer function module (8), the output end of the third non-stationary filtering transfer function module (6) is connected with the other input end of the second inertia link correction type incoherent transfer function module (9), the first inertia link correction type incoherent transfer function module (7) and the inertia correction type coherent transfer function module (8) ) Output of (2)The output ends of the first summing module (10) are connected with the input end of the left excitation head servo control unit, the output ends of the second inertia link correction type incoherent transfer function module (9) and the inertia link correction type coherent transfer function module (8) are connected with the input end of the second summing module (11), and the output end of the second summing module (11) is connected with the input end of the right excitation head servo control unit.

2. The method for outputting road surface excitation of a road surface excitation output system based on measured data reconstruction as claimed in claim 1, comprising the steps of:

step A: the first inertia link correction type coherent transfer function calculation module (12) is used for measuring the left and right track road surface unevenness actual measurement data L₁(I) And R₁(I) Processing to obtain an inertial link correction type coherent transfer function H₁(S) reacting H₁(S) inputting the data into an inertial link correction type coherent transfer function module (8); an inertia link correction type incoherent transfer function calculation module (13) measures the left and right wheel track road surface unevenness actual measurement data L₁(I) And R₁(I) Processing to obtain an inertial link correction type incoherent transfer function H₂(S) reacting H₂(S) is input into a first inertia link correction type incoherent transfer function module (7) and a second inertia link correction type incoherent transfer function module (9), and a nonstationary filtering transfer function calculation module (14) performs actual measurement data L on the left and right wheel track road surface unevenness₁(I) And R₁(I) Processing to obtain a non-stationary filter transfer function H₀(S), filtering the transfer function H₀(S) are respectively input into a first, a second and a third non-stationary filter transfer function module (4, 5, 6);

and B: the first white noise module (1) generates white noise omega₁(t) and input to a first non-stationary filter transfer function module (4), the output of the first non-stationary filter transfer function module (4) is a non-stationary road excitation q₁(t) and inputting the data into a first inertia link correction type incoherent transfer function module (7); the second white noise module (2) generates white noise omega₂(t) and input toA second non-stationary filter transfer function module (5), the output of the second non-stationary filter transfer function module (5) is non-stationary road surface excitation q₂(t) and inputting the signal into an inertial link correction type coherent transfer function module (8); the third white noise module (3) generates white noise omega₃(t) and input to a third non-stationary filter transfer function module (6), the third non-stationary filter transfer function module (6) outputting a non-stationary road excitation q₃(t) and inputting the data into a second inertia element correction type incoherent transfer function module (9):

and C: the first inertia link correction type incoherent transfer function module (7) excites the non-stable road surface q₁(t) processing to obtain left track disturbed road excitation q_Li(t) and input into a first summing module (10); an inertia link correction type coherent transfer function module (8) excites the input non-stable road surface q₂(t) and inertial element correction type coherent transfer function H₁(S) processing to obtain residual road surface excitation q_c(t) and respectively input into a first summation module (10) and a second summation module (11), and a second inertia element correction type incoherent transfer function module (9) excites the input non-smooth road surface q₃(t) processing the signal to obtain right track disturbance road surface excitation q_Ri(t) and input into a second summing module (11);

step D: a first summation module (10) sums an input road excitation q_Li(t)、q_c(t) summing to obtain left wheel rut road surface excitation L₁(t) and input into the left excitation head servo control unit, and a second summation module (11) excites the input road surface q_Ri(t)、q_c(t) summing to obtain right wheel rut road surface excitation R₁(t) and inputting the signal into a right excitation head servo control unit;

step E: the left and right excitation head servo control units excite L according to the rut road surface of the left and right wheels₁(t)、R₁(t) controlling the left and right excitation heads to output simulated road surface excitations L (t) and R (t) in real time.

3. The road surface excitation output method according to claim 2, characterized in that: in step A, an inertial element correction type coherent transfer functionThe number calculation module (12) and the inertia element correction type incoherent transfer function calculation module (13) firstly according to the formula [ Coh2 ]_LRn_R]＝mscohere(L₁(I),R₁(I)，256，[],1024,2n_max) Finding Coh2 a square vector of the coherence function_LRThen according to formula

Find L₁(I) And R₁(I) Coh in the spatial domain_LR，n_RIs and Coh_LRThe data corresponding road surface space frequency vector [ phi ]]Indicating the use of default values;

then an inertia link correction type coherent transfer function calculation module (12) is used for calculating a coherent transfer function according to the formula

Obtaining a fitting parameter alpha₀、α₁、α₂、β₀、β₁And beta₂J is a unit imaginary number; n is the spatial frequency of the pavement; an inertial link correction type incoherent transfer function calculation module (13) is a formula according to

Deriving a fitting parameter psi₀、ψ₁、ψ₂、ξ₀、ξ₁And xi₂A value of (d);

finally, an inertial element correction type coherent transfer function calculation module (12) is according to formula

Obtaining an inertial element correction type coherent transfer function H₁(S), wherein S is a Laplace operator; an inertial link correction type incoherent transfer function calculation module (13) is a formula according to

Obtaining an inertial link correction type incoherent transfer function H₂(S)。

4. The road surface excitation output method according to claim 2, characterized in that: in the step A, the non-stationary filter transfer function calculation module (14) firstly finds out L₁(I) And R₁(I) Self-power spectral density G in the spatial domain of_LAnd G_RAccording to formula (I)

Calculating the estimated road surface excitation coefficient

n is the spatial frequency of the pavement; then according to formula

Obtaining a fitting parameter χ₀、χ₁、χ₂、χ₃、μ₁、μ₂、μ₃；n_sThe frequency point with the maximum error after the initial correction is obtained; n is_minThe lower cut-off frequency of the uneven road surface; finally according to formula

Obtaining a non-stationary filter transfer function H₀(S)。

5. The road surface excitation output method according to claim 2, characterized in that: in step D, the first summation module (10) is based on the formula L₁(t)＝q_Li(t)+q_c(t) calculating left wheel rut road surface excitation L₁(t) the second summing module (11) is according to the formula R₁(t)＝q_Ri(t)+q_c(t) calculating left wheel rut road surface excitation R₁(t)。

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