Comprehensive implementation method of angle module configuration vehicle electromechanical inerter suspension network

Abstract

The invention discloses a comprehensive implementation method of an angle module configuration vehicle electromechanical inerter suspension network. The method comprises the following steps: step 1, an integer order continuous model approximation method of a fractional order system based on an Oustaloup filter; 2, network comprehensive implementation of five elements of a biquadratic impedance transfer function based on a regular real function; 3, performing comparison simulation verification on frequency characteristics of the integer order approximation circuit system and the fractional order ideal element; and 4, comparing dynamic performance errors of the angular module configuration vehicle fractional order electromechanical inerter suspension and the integer order approximation structure. The method has the beneficial effects that the problem that the fractional order electrical element only exists in theory is solved, and a theoretical reference and a feasible method are provided for network comprehensive implementation of the fractional order electrical element and the angular module configuration vehicle electromechanical inerter suspension based on the fractional order quadratic transfer function.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle suspension vibration isolation, in particular to a method for comprehensively realizing an electromechanical inertia suspension network for a corner module configuration vehicle. Background Art

[0002] The corner module is an integrated module that integrates drive, braking, steering, and suspension functions. Its design aims to reduce mechanical transmission components and optimize vehicle layout space, enabling each wheel to have special driving capabilities such as independent 90-degree steering, on-the-spot U-turns, and lateral translation, thereby improving the vehicle's steering and mobility. However, it also greatly increases the complexity of vehicle design and control. Its drive motor is distributed in the wheel hub, significantly increasing the vehicle's unsprung mass and significantly changing its vertical motion characteristics. This leads to a series of problems such as increased vertical vibration acceleration of the vehicle body, deteriorated wheel ground contact, and the negative effects of unbalanced electromagnetic radial excitation, which seriously affect vehicle handling, ride smoothness, and stability. The traditional suspension system is based on the "spring-damper" two-element structural system, and the dynamic action boundary is constrained by only stiffness impedance and damping impedance, which limits the performance improvement; the introduction of inertia makes it jump to a new three-element mechanical vibration isolation network composed of "spring (k)-damper (c)-inertia (b)", and realizes the complete correspondence of the electromechanical similarity theory based on "force-current", which provides new ideas for the design of passive suspension. The comprehensive concept of passive network in the electrical field is extended to the structural design of vehicle suspension system; the external circuit design of the electromechanical inertia capacitor composed of a ball screw inertia capacitor and a rotating motor can realize complex impedance output with passive electrical components, but with the increase of the order of the integer-order transfer function, while the vibration isolation performance is improved, the complexity of the implementation method is further increased, that is, the number of components required for implementation increases, the implementation conditions are strict, and the vibration isolation performance is improved. The implementation theory is complex; in this context, fractional-order calculus theory brings a new perspective. Currently, some research has focused on fractional-order control theory or the use of fractional-order transfer functions to design the external circuit of vehicle inertial suspension, and some results have been achieved. The integrated approach of fractional-order calculus theory and fractional-order biquadratic transfer functions is used to design the external circuit of the electromechanical inertial device, breaking through the bottleneck of existing research on electromechanical inertial devices, which is limited to fractional-order passive networks with three-element structures. Its structure is simple and can exhibit the characteristics of fractional-order complex impedances, providing new ideas for the structural design methods of vehicle electromechanical inertial suspension. However, these studies are still limited to theoretical research. Although the theoretical research and application potential of fractional-order electrical components are significant, their actual implementation still faces many technical and theoretical challenges, such as complex circuit simulation networks, the introduction of active devices, and difficult material processing. In view of the above situation, it is necessary to introduce the approximation method of fractional-order calculus operators to approximate the integer-order biquadratic transfer function of fractional-order electrical components, so as to realize the network synthesis of the angular module configuration automotive electromechanical inertial suspension, so that it can fit the actual engineering application. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: to address the problem that fractional-order electrical components of a fractional-order angular module configuration vehicle electromechanical inertial suspension cannot be realized, and to propose a comprehensive implementation method for the angular module configuration vehicle electromechanical inertial suspension network, so that it can be implemented in production and life.

[0004] The technical solution of the present invention to achieve the above-mentioned purpose is a method for comprehensively implementing an electromechanical inertia suspension network for an angular module configuration vehicle, comprising the following steps: Step 1: Integer-order continuous model approximation method for fractional-order systems based on Oustaloup filter; Step 2: Network synthesis implementation of five-element biquadratic impedance transfer function based on regular real function; Step 3: Comparative simulation verification of the frequency characteristics of the integer-order approximation circuit system and the fractional-order ideal components; Step 4: Comparison of the dynamic performance error between the corner module configuration vehicle fractional-order electromechanical inertia suspension and the integer-order approximation structure.

[0005] As a further supplement to the present technical solution, the first step proposes an integer-order continuous model approximation method for a fractional-order system, that is, designing an integer-order continuous filter to simulate as closely as possible the fractional-order operator approximating the original fractional-order model when driven by an unknown signal; A fractional-order control system can be described by a transfer function of the following form: Where, a 0 ,… , a n and b 0 ,… , b m are the coefficients of the fractional-order transfer function, s is the Laplace operator, a 0 ,… , a n and ,… , is the order of the Laplace operator; In order to obtain the discrete model of the fractional-order system, the discrete approximation of the transfer function is used using fractional-order calculus to obtain the discrete transfer function of the fractional-order system. G ( z ) is the general expression: Where, Plath operator s The discrete equivalent of , expressed as a complex variable z or shift operator function.

[0006] As a further supplement to the present technical solution, the step 1 is approximated using the Oustaloup method, which is based on the function form: , Where, H ( s ) is the transfer function of the system, where is the fractional calculus operator, s is the Laplace operator, is the order of the fractional-order control system; The standard form of the Oustaloup filter is: Where, is the fractional-order system transfer function Integer-order approximation of , K is the gain constant, N is the order of approximation, s is the Laplace operator, and Respectively k The first and k The frequency corresponding to each zero point is in rad / s.

[0007] To further supplement this technical solution, the Oustaloup filter synthesis formula used in step 1 is: in, is the unity gain frequency and the center frequency of the frequency band geometrically distributed around it; that is, , and are high transition frequency and low transition frequency, respectively. and are the frequencies corresponding to the first zero and the first pole, in rad / s. is the proportionality constant between the zero and pole frequencies, is the geometric sequence scale factor, is the common ratio of the frequency sequence, 、 and Respectively k Zero point, k The angular frequency of the first pole and the last zero is in rad / s. N is the filter order, μ is the order of the fractional-order control system.

[0008] As a further supplement to this technical solution, step 2 uses the concept and properties of regular real functions to solve the problem of passive realization of the five-element biquadratic impedance transfer function. The regular real function is defined as: If a real rational function Z ( s )exist or When it reaches its minimum value, it is called a regular real function; the properties of regular functions can be expressed as: like Z ( s ) is a regular real function, then , , and are all regular; And, when A 、 B 、 C 、 D 、 E 、 F When any one of is 0, the positive real function Z ( s ) is regular, and can be realized by connecting at most two reactive elements and two resistive elements in series or parallel.

[0009] As a further supplement to this technical solution, step 2 uses two types of transformation rules to change the quadrant, specifically including: (1) Dual transformation ( , or dual) is that the types of inductors and capacitors are interchanged, and their values ​​remain fixed; while the types of resistors remain unchanged, their values ​​are reciprocals of each other, and the series and parallel connection relationships of the original network are interchanged.

[0010] (2) Inverse frequency transform ( ) is that the types of inductors and capacitors are interchanged and their values ​​are reciprocals of each other; the resistors remain unchanged.

[0011] As a further supplement to the present technical solution, the step three analyzes the frequency characteristics of the fractional-order capacitors, fractional-order inductors, fractional-order external circuits, and their corresponding integer-order approximation circuit systems, and draws their Bode diagrams.

[0012] To further supplement this technical solution, the specific implementation method of step 4 is as follows: determine the angular module configuration vehicle electromechanical inertia suspension model and suspension parameters of the fractional-order biquadratic transfer function, and drive over a road surface with a roughness coefficient of 256×10 -6 m 3 ·cycle -1 The simulation time is 10 seconds, the sampling interval is 0.001 seconds, and a random road surface model determined by Gaussian white noise with zero mean is selected. The suspension performance indicators of the electromechanical inertial suspension for vehicles with an integer-order approximation structure and an ideal fractional-order angular module configuration are calculated under random road input conditions, including body acceleration, suspension dynamic travel, and tire dynamic load. These indicators are compared and analyzed with the corresponding indicators of the passive suspension of vehicles with a traditional angular module configuration.

[0013] Its beneficial effects are as follows: 1. The present invention applies the approximation method of fractional-order calculus operators to the comprehensive implementation of fractional-order electrical components of a fractional-order angular module-configured automotive electromechanical inertial suspension. An integer-order continuous filter is designed to simulate as closely as possible the fractional-order operator's approximation to the original fractional-order model when driven by an unknown signal, thereby achieving integer-order biquadratic transfer function approximation for a single fractional-order electrical component. This provides a practical path for the engineering application of fractional-order components and promotes the practical application of fractional-order systems in a wider range of fields.

[0014] 2. This invention proposes a network-based integrated implementation method for an electromechanical inertial suspension system for vehicles with an angular modular configuration. This method utilizes regular real functions to solve the problem of passively implementing a five-element biquadratic impedance transfer function. This method passively implements fractional-order electrical components using a five-element network-based integrated implementation, resolving a theoretical challenge for fractional-order electrical components. This method provides a theoretical reference and a practical approach for the network-based integrated implementation of fractional-order electrical components and electromechanical inertial suspension systems for vehicles with an angular modular configuration based on fractional-order quadratic transfer functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a flow chart of a comprehensive implementation method of an electromechanical inertia suspension network for an angular module configuration vehicle; Figure 2 It is a quarter vehicle suspension dynamics model diagram; Figure 3 It is a structural diagram of the electromechanical inertia suspension system; Figure 4 It is one of the five components of the biquadratic admittance function network synthesis; Figure 5 It is the second of the five components of the biquadratic admittance function network synthesis; Figure 6 It is a fractional-order capacitor approximation circuit; Figure 7 It is a fractional-order inductor approximation circuit; Figure 8 is the Bode plot of fractional capacitance and its approximation; Figure 9 is the Bode plot of fractional inductance and its approximation; Figure 10 is the Bode diagram of the fractional-order external terminal circuit and its approximation; Figure 11 This is a comparison chart of suspension performance errors under random road input; In the formula of the present invention: is the sprung mass, is the unsprung mass, is the Laplace operator, k is the stiffness of the suspension support spring, c is the damping coefficient of the suspension; is the equivalent spring stiffness of the tire, is the vertical displacement of the sprung mass, is the vertical displacement of the unsprung mass, is the vertical input displacement of road roughness, 、 、 They are 、 、 The Laplace change of B ( s ) is the velocity impedance expression of the electromechanical inertia vessel, b is the inertia coefficient of the electromechanical inertia vessel, P is the lead of the electromechanical inertia vessel, is the thrust coefficient of the rotating motor, is the electromotive force constant of the rotating motor; Y e ( s ) is the transfer function expression of the external circuit of the rotating motor, A , B , C , D , E , F , G , H are the coefficients of the fractional-order biquadratic transfer function, , is the order of the transfer function. DETAILED DESCRIPTION

[0016] In order to make the technical solution more clear to those skilled in the art, Figure 1-11 Explain the specific structure and principle of each of the above mechanisms: The structure of the fractional-order electromechanical inertia suspension for corner module configuration vehicles is as follows: Figure 2 As shown, the introduction of an inertia capacitor in the traditional two-element "spring-damper" suspension system transforms it into a novel three-element mechanical vibration isolation network consisting of a "spring (k)-damper (c)-inertia capacitor (b)." The electromechanical inertia capacitor used in this invention is composed of a ball screw-type inertia capacitor coupled to a rotating motor. The flywheel and ball screw rotate coaxially with the rotor shaft of the rotating motor through a coupling. When the two ends of the electromechanical inertia capacitor experience relative displacement, it drives the rotating motor to generate an AC terminal voltage, which couples with the electrical network impedance of the external circuit. Increasing the integer-order transfer function of the external circuit can improve the vibration isolation performance of the suspension system, but this also leads to problems such as an increase in the number of components required, stringent implementation conditions, and complex theoretical implementation.

[0017] Fractional-order circuit elements are obtained by expanding the traditional circuit elements using fractional-order calculus theory. They are an extension of integer-order elements. The external circuit of the electromechanical inertial capacitor is designed using the integrated method of fractional-order calculus theory and fractional-order biquadratic transfer functions. Part of the effect of high-order integer-order transfer functions can be achieved through low-order fractional-order transfer functions. However, fractional-order differential equations are complex to solve and rely on numerical methods or special functions. The calculation cost is high, and it is difficult for actual materials to strictly meet the characteristics of fractional-order electrical components. In order to enable fractional-order electrical components to be implemented in production and life, the present invention proposes a comprehensive implementation method for an electromechanical inertial capacitor suspension network with an angular module configuration for vehicles, such as Figure 1 As shown, it is characterized in that it includes the following working steps: Step 1: Integer-order continuous model approximation method for fractional-order systems based on Oustaloup filter; Step 2: Network synthesis implementation of five-element biquadratic impedance transfer function based on regular real function; Step 3: Comparative simulation verification of the frequency characteristics of the integer-order approximation circuit system and the fractional-order ideal components; Step 4: Comparison of the dynamic performance error between the corner module configuration vehicle fractional-order electromechanical inertia suspension and the integer-order approximation structure.

[0018] Step 1 proposes an integer-order continuous model approximation method for fractional-order systems, that is, designing an integer-order continuous filter to simulate as closely as possible the fractional-order operator approximating the original fractional-order model when driven by an unknown signal; A fractional-order control system can be described by a transfer function of the following form: Where, a 0 , … , a n and b0 , … , b m are the coefficients of the fractional-order transfer function, s is the Laplace operator, a 0 ,… , a n and ,… , is the order of the Laplace operator; In order to obtain the discrete model of the fractional-order system, the discrete approximation of the transfer function is used using fractional-order calculus to obtain the discrete transfer function of the fractional-order system. G ( z ) is the general expression: Where, Plath operator s The discrete equivalent of , expressed as a complex variable z or shift operator function.

[0019] The first step is approximated using the Oustaloup method, which is based on the following function: , Where, is the transfer function of the system, which is a fractional calculus operator. s is the Laplace operator, is the order of the fractional-order control system; The standard form of the Oustaloup filter is: Where, is the fractional-order system transfer function Integer-order approximation of , K is the gain constant, N is the order of approximation, s is the Laplace operator, and Respectively k The first and k The frequency corresponding to each zero point is in rad / s.

[0020] The Oustaloup filter synthesis formula used in step 1 is: in, is the unity gain frequency and the center frequency of the frequency band geometrically distributed around it; that is, , and are high transition frequency and low transition frequency, respectively. and are the frequencies corresponding to the first zero and the first pole, in rad / s. is the proportionality constant between the zero and pole frequencies, is the geometric sequence scale factor, is the common ratio of the frequency sequence, 、 and Respectively k Zero point, k The angular frequency of the first pole and the last zero is in rad / s. N is the filter order, μ is the order of the fractional-order control system.

[0021] Step 1 requires first establishing a dynamic model of the fractional-order electromechanical inertia suspension for corner module configuration vehicles. Its structure is as follows: Figure 2 As shown, the fractional order suspension structure is as follows Figure 3 As shown in Figure 1, the structure consists of three resistors, one fractional-order capacitor, and one fractional-order inductor. The parameters of each component are shown in Table 1.

[0022] Table 1 Electrical component parameters In view of the fact that the implementation form of the equivalent circuit and the fractional-order controller is a finite-dimensional integer-order system approximated by a fractional-order or infinite-dimensional system, the present invention uses an integer-order continuous model approximation method for the fractional-order system, and designs an integer-order continuous filter to simulate the fractional-order operator as much as possible when driven by an unknown signal to approximate the original fractional-order model. In step one, the integer-order biquadratic transfer function of a single fractional-order electrical component is approximated by the Oustaloup filtering algorithm, and the integer-order biquadratic transfer function is used to approximate the approximate effect of the fractional-order electrical component. The integer-order biquadratic transfer function corresponding to the fractional-order electrical component can be obtained, which provides a basis for the network synthesis implementation of the subsequent steps. According to the fractional-order electrical component parameters in Table 1, the fractional-order capacitor can be approximated as: According to the fractional-order electrical component parameters in Table 1, the fractional-order capacitor can be approximated as: Where, is the fractional capacitance, is the fractional capacitor order, s is the Laplace operator.

[0023] The fractional-order inductance is approximated as: Where, is the fractional-order inductor, is the order of fractional inductance, s is the Laplace operator.

[0024] After obtaining a specific integer-order biquadratic transfer function, in step 2, the obtained integer-order approximate transfer function is verified to be positive and real, and a five-element network synthesis passive implementation is performed on it under the condition that the approximate transfer function is verified to be positive and real.

[0025] Specifically for the case of admittance function passive network synthesis, the integer-order biquadratic transfer function obtained is rewritten as follows: For the biquadratic admittance function : In the formula, the coefficient A 、 B 、 C 、 D 、 E 、 F ≥ 0, s is the Laplace operator. The necessary and sufficient conditions for being a positive real function are: The product of the numerator and denominator in the biquadratic admittance function is: Combining the concepts and properties of regular real functions, if the biquadratic admittance function Any coefficient in A 、 B 、 C 、 D 、 E 、 F If there is a coefficient of 0, the admittance function is regular and can be realized by a series-parallel structure of at most two reactive elements and two resistive elements.

[0026] If and only if the biquadratic admittance function The admittance function is regular if at least one of the following four conditions is met: Case 1: and ; Case 2: and ; Case 3: CD - AF ≤ 0 and ; Case 4: CD - AF ≤ 0 and ; When the biquadratic admittance function Y ( s ) in any coefficient A 、 B 、 C 、 D 、 E 、 F When both are greater than 0, the admittance function can be rewritten as follows: Where, s is the Laplace operator, U 、 V 、 W are coefficients, all of which are greater than 0, and the expression is: The product of the numerator and denominator in the biquadratic admittance function is rewritten as: Admittance function Y c ( s ) can be realized by using a passive network of two reactive elements and three resistive elements. The specific structure is as follows: Figure 4 and Figure 5 As shown in the quadrant of , Table 2 gives the feasible conditions for network synthesis of this regular real function: Table 2 Network comprehensive implementation conditions Substituting the integer-order approximate biquadratic transfer function of each fractional-order electrical component into the implementation conditions of Table 2 for passive network synthesis, the corresponding electrical network structure and parameters can be obtained, thereby realizing the network synthesis of fractional-order electrical components.

[0027] Substituting the integer-order approximation biquadratic transfer function of the fractional-order capacitor into the implementation conditions of Table 2, the passive network synthesis is performed and the following is obtained: Figure 6 Table 3 shows the values ​​of the corresponding electrical component parameters.

[0028] Table 3 Fractional-order capacitor approximation circuit element parameters Substituting the integer-order approximation biquadratic transfer function of the fractional-order inductor into the realization conditions of Table 2, the passive network synthesis is carried out and the following is obtained: Figure 7Table 4 shows the values ​​of the corresponding electrical component parameters.

[0029] Table 4 Fractional-order inductor approximate circuit element parameters Frequency characteristics analysis is an effective method for translating transfer functions from the complex domain to the frequency domain, where physical concepts are clearly defined. This method establishes a direct relationship between a system's time response and its spectrum, as well as between its unit impulse response and its frequency characteristics. It also bridges the gap between system research and analysis in the time and frequency domains. The effectiveness of the network synthesis implementation method of the present invention can be verified by comparing Bode plots of fractional-order electrical components and their integer-order approximation circuit systems through simulation analysis.

[0030] Step three, comparative simulation verification of the frequency characteristics of the integer-order approximation circuit system and the fractional-order ideal components, analyze the frequency characteristics of the integer-order approximation circuit system and the fractional-order ideal components implemented in step two, and verify the frequency characteristics of the circuit system through Bode diagram simulation.

[0031] The Bode diagrams of fractional capacitors, fractional inductors and fractional external circuits are shown as follows: Figure 8 、 Figure 9 、 Figure 10 As shown, it can be seen that the approximate method is close to the theoretical value in terms of amplitude, but in terms of phase, although it is not close to the theoretical value at the frequency of 10 -2 Hz-10 2 There is a slight difference in the Hz range, but the overall trend remains consistent, indicating that this method can approximately achieve network synthesis of fractional-order electrical components.

[0032] In step 4, the dynamic performance error comparison of the integer-order approximation structure of the fractional-order electromechanical inertia suspension for corner module configuration vehicles is carried out. The inertia suspension with the integer-order approximation structure implemented in step 2 is simulated and compared with the ideal fractional-order inertia suspension under road input to verify the effectiveness of the implementation method. The specific implementation method is as follows: according to Figure 2 The dynamic Lagrangian equation for the electromechanical inertia suspension model of the corner module configuration shown is: In the formula is the sprung mass, is the unsprung mass, is the Laplace operator, k is the stiffness of the suspension support spring, c is the damping coefficient of the suspension; is the equivalent spring stiffness of the tire, is the vertical displacement of the sprung mass, is the vertical displacement of the unsprung mass, is the vertical input displacement of road roughness, 、 、 They are 、 、 The Laplace change of B ( s ) is the velocity impedance expression of the electromechanical inertia container, which is: Where, b is the inertia coefficient of the electromechanical inertia container, is the Laplace operator, P is the lead of the electromechanical inertia vessel, is the thrust coefficient of the rotating motor, is the electromotive force constant of the rotating motor. Y e ( s ) is the transfer expression of the external circuit of the rotating motor, which is: In the formula A , B , C , D , E , F , G , H are the coefficients of the fractional-order biquadratic transfer function, , is the order of the transfer function, s is the Laplace operator.

[0033] Table 5 shows the suspension model parameters.

[0034] The transfer function parameters of the fractional-order biquadratic transfer function of the angular module configuration vehicle electromechanical inertia suspension are shown in Table 6.

[0035] Table 6 Fractional-order transfer function parameters The ideal fractional inertia suspension structure is as follows Figure 3 As shown, the specific component parameters have been given in Table 1 above.

[0036] The simulation is carried out at a speed of 20 m / s and the road surface roughness coefficient is 256×10 -6 m 3 ·cycle -1The simulation time is 10s, the sampling interval is 0.001s, and a random road surface model determined by Gaussian white noise with zero mean is selected. The suspension performance indicators of the electromechanical inertial suspension with an integer-order approximation structure and the ideal fractional-order angular module configuration are calculated under random road input conditions, including body acceleration, suspension dynamic travel, and tire dynamic load. The corresponding indicators are compared and analyzed with the corresponding indicators of the passive suspension of the traditional angular module configuration vehicle, and the root mean square error of the performance indicators of the inertial suspension with an integer-order approximation structure compared with the fractional-order inertial suspension is given.

[0037] Table 7 Comparison of suspension performance errors Figure 11 In the time-domain graphs shown, the vehicle acceleration (a) and tire dynamic load (c) are approximated very well. As shown in Table 7, the RMS errors for these two dynamic performance indicators are less than 1%. However, the approximation of suspension travel is poor, with an RMS error of 7.69%. However, compared to traditional passive suspension, there is still a significant reduction in suspension travel. These results demonstrate the feasibility of the proposed method for the integrated implementation of a corner module-based electromechanical inertia suspension network for vehicles. It can also serve as a theoretical reference for the passive implementation of fractional-order electromechanical inertia suspension for vehicles.

[0038] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Any changes that may be made to certain parts thereof by those skilled in the art all reflect the principles of the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for realizing a comprehensive electromechanical inertia suspension network for an angular module configuration vehicle, characterized in that: The following steps are involved: Step 1: Integer-order continuous model approximation method for fractional-order systems based on Oustaloup filter; Step 2: Network synthesis implementation of five-element biquadratic impedance transfer function based on regular real function; Step 3: Comparative simulation verification of the frequency characteristics of the integer-order approximation circuit system and the fractional-order ideal components; Step 4: Comparison of the dynamic performance error between the corner module configuration vehicle fractional-order electromechanical inertia suspension and the integer-order approximation structure.

2. The method for realizing a comprehensive electromechanical inertia suspension network for a corner module configuration vehicle according to claim 1, characterized in that: The first step proposes an integer-order continuous model approximation method for a fractional-order system, that is, designing an integer-order continuous filter to simulate as closely as possible the fractional-order operator approximating the original fractional-order model when driven by an unknown signal; A fractional-order control system can be described by a transfer function of the following form: Where, a 0 ,… , a n and b 0 ,… , b m are the coefficients of the fractional-order transfer function, s is the Laplace operator, a 0 ,… , a n and ,… , is the order of the Laplace operator; In order to obtain the discrete model of the fractional-order system, the discrete approximation of the transfer function is used using fractional-order calculus to obtain the discrete transfer function of the fractional-order system. G ( z ) is the general expression: Where, Plath operator s The discrete equivalent of , expressed as a complex variable z or shift operator function.

3. The method for realizing a comprehensive electromechanical inertia suspension network for a corner module configuration vehicle according to claim 2, characterized in that: The first step is approximated using the Oustaloup method, which is based on the following function: Where, is the transfer function of the system, which is a fractional calculus operator. s is the Laplace operator, is the order of the fractional-order control system; Where, is the fractional-order system transfer function Integer order approximation of , K is the gain constant, N is the order of approximation, s is the Laplace operator, and Respectively k The first and k The frequency corresponding to each zero point is in rad / s.

4. The method for realizing a comprehensive electromechanical inertia suspension network for a corner module configuration vehicle according to claim 3, characterized in that: The Oustaloup filter synthesis formula used in step 1 is: in, is the unity gain frequency and the center frequency of the frequency band geometrically distributed around it; that is, , and are high transition frequency and low transition frequency, respectively. and are the frequencies corresponding to the first zero and the first pole, in rad / s. is the proportionality constant between the zero and pole frequencies, is the geometric sequence scale factor, is the common ratio of the frequency sequence, 、 and Respectively k Zero point, k The angular frequency of the first pole and the last zero is in rad / s. N is the filter order, is the order of the fractional-order control system.

5. The method for realizing a comprehensive electromechanical inertia suspension network for a corner module configuration vehicle according to claim 1, characterized in that: The second step uses the concept and properties of regular real functions to solve the problem of passive realization of the five-element biquadratic impedance transfer function. The regular real function is defined as: If a real rational function Z ( s )exist or When it reaches its minimum value, it is called a regular real function; the properties of regular functions can be expressed as: like Z ( s ) is a regular real function, then , , and are all regular; And, when A 、 B 、 C 、 D 、 E 、 F When any one of is 0, the positive real function Z ( s ) is regular, and can be realized by connecting at most two reactive elements and two resistive elements in series or parallel.

6. The method for realizing a comprehensive electromechanical inertia suspension network for a corner module configuration vehicle according to claim 5, characterized in that: The second step uses two types of transformation rules to change the quadrant, specifically including: (1) The rules of dual transformation are: the types of inductors and capacitors are interchanged, and their values ​​remain unchanged; while the types of resistors remain unchanged, and their values ​​are reciprocal to each other, and the series and parallel connection relationships of the original network are interchanged. (2) The rule for inverse frequency conversion is: the types of inductance and capacitance components are interchanged, and their values ​​are reciprocal to each other; the resistance component remains unchanged.

7. The method for realizing a comprehensive electromechanical inertia suspension network for a corner module configuration vehicle according to claim 1, characterized in that: The step three analyzes the frequency characteristics of the fractional-order capacitors, fractional-order inductors, fractional-order external circuits, and their corresponding integer-order approximation circuit systems, and draws their Bode diagrams.

8. The method for realizing a comprehensive electromechanical inertia suspension network for a corner module configuration vehicle according to claim 1, characterized in that: The specific implementation method of step 4 is as follows: determine the electromechanical inertia suspension model and suspension parameters of the angular module configuration of the fractional-order biquadratic transfer function, and drive over a road surface with a roughness coefficient of 256×10 -6 m 3 ·cycle -1 The simulation time is 10 seconds, the sampling interval is 0.001 seconds, and a random road surface model determined by Gaussian white noise with zero mean is selected. The suspension performance indicators of the electromechanical inertial suspension for vehicles with an integer-order approximation structure and an ideal fractional-order angular module configuration are calculated under random road input conditions, including body acceleration, suspension dynamic travel, and tire dynamic load. These indicators are compared and analyzed with the corresponding indicators of the passive suspension of vehicles with a traditional angular module configuration.

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