CN106379127A - Electro-hydraulic integrated type self-energy supplying active suspension actuator and control method thereof - Google Patents

Abstract

The invention discloses an electro-hydraulic integrated type self-energy supplying active suspension actuator which comprises an actuator main body and an actuator controller, wherein the actuator main body comprises a piston barrel, a piston, an upper piston rod, a lower piston rod, an upper lug ring, a lower lug ring, an upper piston barrel end cover, a lower piston barrel end cover, an upper sleeve, an upper guide base, an upper oil seal, a first sealing ring, a lower sleeve, a lower guide base, a lower oil seal, a second sealing ring and a hydraulic oil; a check valve set, a hydraulic motor module and a brushless direct current motor are embedded into the piston; the check valve set comprises a flow valve, a compression valve, a compensation valve and a rebound valve; the hydraulic motor module comprises a hydraulic motor shell, a shaft sleeve, a first gear, a second gear and a third gear. The invention also discloses a control method for the electro-hydraulic integrated type self-energy supplying active suspension actuator. The electro-hydraulic integrated type self-energy supplying active suspension actuator is novel and reasonable in design, convenient in realization and low in cost; the suspension actuator can be under the optimal vibration attenuation state; the driving smoothness and the operation stability of the vehicle can be more effectively promoted.

Description

Hydro-electric integrated self-powered active suspension actuator and control method thereof

Technical Field

The invention belongs to the technical field of automobile suspension systems, and particularly relates to a hydro-electric integrated self-powered active suspension actuator and a control method thereof.

Background

During running of the vehicle, the sprung mass and the unsprung mass of the vehicle are displaced relative to each other due to road surface unevenness and the like, so that the vehicle vibrates. The suspension system is a key component determining the dynamic performance of the vehicle operation, and determines the ride comfort and ride comfort of the vehicle. The current vehicle suspension system mainly comprises a passive suspension, a semi-active suspension and an active suspension. Because the parameters such as rigidity and damping are fixed and unchangeable, the vibration damping effect of the traditional passive suspension is greatly limited, the vibration damping performance of the suspension can not be changed timely along with the excitation change of a road surface, and because the semi-active suspension can only change the rigidity or the damping, the semi-active suspension can only ensure that the automobile can reach the optimal performance under a specific road state and driving speed, so that the driving smoothness and riding comfort of the automobile are influenced to a certain extent, and the active suspension can timely adjust the parameters of the suspension according to the motion state and the road surface condition of the automobile to ensure that the suspension is in the optimal vibration damping state, so that the active suspension has better vibration damping effect compared with the passive suspension and the semi-active suspension and is more and more widely concerned by people, but the traditional active suspension needs to consume a large amount of energy, and high energy consumption is one of main factors for limiting the popularization of the active suspension in the, and the energy feedback type active suspension provides a scientific method for solving the problem. At present, an energy feedback type active suspension mainly comprises: rack and pinion type, ball screw type, linear motor type, and electrohydraulic type. The energy recovery system of the gear rack type or the ball screw type which adopts the mechanical device to convert the linear motion into the rotary motion has the defects of being influenced by the internal clearance of the transmission system, being easy to wear and have poor stability, and the motor and the transmission system are in solid connection, so that the motor can continuously change the rotating direction along with the system vibration, the generator is enabled to continuously rotate positively and negatively, a large amount of inertia loss can be caused, the system energy feedback efficiency is low, the service life of the generator can be shortened, and the system reliability is poor. The linear motor type active suspension has the defects of complex support structure, large leakage magnetic flux, low energy feedback efficiency, relatively high manufacturing cost and the like, while the electrohydraulic type active suspension has the advantages of stable response, low cost, stable performance, high reliability and the like, but the integration degree is low due to the fact that the conventional electrohydraulic type active suspension comprises a hydraulic pipeline, an energy accumulator, a motor and other components, and the popularization and the application of the electrohydraulic type active suspension in the market are limited. For example, chinese patent application No. 201510330250.6 discloses a hydraulic-electric energy feedback type shock absorber using two check valve pipelines, which mainly comprises a hydraulic working cylinder, a first check valve, a second check valve, an energy accumulator, a hydraulic motor, a generator, a hydraulic pipeline, and an oil supplementing device comprising an oil storage cylinder, a compression valve, and a compensation valve.

Meanwhile, the current electrohydraulic energy feedback shock absorber only considers the energy recovery efficiency and neglects the shock absorption effect of the suspension system, so that the control effect is poor. For example, chinese patent application No. 201010108889.7 discloses a hydraulic-electric energy feedback type shock absorber, which includes a hydraulic circuit, a working chamber and a piston, wherein the working chamber is divided into a piston working chamber and an energy storage and power generation chamber by a partition plate, wherein: the piston is positioned in the piston working cavity and is connected with an external upper mounting base through a piston push rod; the hydraulic motor is positioned in the energy storage power generation cavity and is connected with an external rotary power generator through a transmission shaft; the energy accumulator is positioned in the energy storage and power generation cavity and below the partition plate; the hydraulic circuit and a plurality of one-way valves form a hydraulic rectifier bridge, and the hydraulic circuit is in a form that an external pipeline is arranged outside the piston or the piston is designed into an inner cavity and an outer cavity. This hydraulic electricity is presented can formula shock absorber and only can work under the mode of energy repayment, through the electric current of adjustment generator, and then the electromagnetic resistance moment of adjustment generator to adjust whole suspension system's damping force, what its essence was accomplished is the control process of semi-active suspension, owing to do not have the output of active control power, shock attenuation effect and control law design receive the restriction, also will influence the ride comfort that the vehicle went and the improvement degree of handling stability simultaneously.

Disclosure of Invention

The invention aims to solve the technical problem of providing a liquid-electricity integrated self-powered active suspension actuator which has the advantages of simple structure, novel and reasonable design, convenient implementation, low cost, capability of enabling the suspension actuator to be in the optimal vibration damping state, better improvement of the smoothness and the operation stability of vehicle running, strong practicability, good use effect and convenience for market popularization, and aims to overcome the defects in the prior art.

In order to solve the technical problems, the invention adopts the technical scheme that: the utility model provides a hydroelectricity integrated form self-powered initiative suspension actuator which characterized in that: the actuator comprises an actuator body and an actuator controller, wherein the actuator body comprises a piston cylinder, a piston, an upper piston rod, a lower piston rod, an upper lug ring and a lower lug ring, the upper part of the piston cylinder is connected with an upper end cover of the piston cylinder, the lower part of the piston cylinder is connected with a lower end cover of the piston cylinder, the lower lug ring is connected with a lower end cover of the piston cylinder, the piston is arranged at the middle upper part in the piston cylinder, the lower end of the upper piston rod is connected with the piston, the upper end of the lower piston rod is connected with the piston, the upper end of the upper piston rod penetrates out of the upper end cover of the piston cylinder and is connected with the upper lug ring, the upper part in the piston cylinder is fixedly connected with an upper bushing, an upper guide seat which is sleeved on the upper piston rod and used for guiding the up-and-down movement of the upper piston rod is connected through an upper snap ring, an upper, the upper oil seal is sleeved with a first sealing ring positioned between the upper end cover of the piston cylinder and the upper bushing; the lower middle part in the piston cylinder is fixedly connected with a lower bushing, a lower guide seat which is sleeved on the lower piston rod and used for guiding the up-and-down movement of the lower piston rod is connected in the lower bushing in a clamping manner through a lower clamping ring, a lower oil seal sleeved on the lower piston rod is arranged at the lower part of the lower guide seat, and a second sealing ring positioned at the lower part of the lower bushing is sleeved on the lower oil seal; a cavity positioned among the upper bushing, the upper guide seat and the piston in the piston cylinder is an upper piston cylinder cavity, a cavity positioned among the lower bushing, the lower guide seat and the piston in the piston cylinder is a lower piston cylinder cavity, and hydraulic oil is arranged in the upper piston cylinder cavity and the lower piston cylinder cavity; a one-way valve group, a hydraulic motor module and a brushless direct current motor are embedded in the piston, the one-way valve group comprises a flow valve, a compression valve, a compensation valve and an extension valve, the hydraulic motor module comprises a hydraulic motor shell and a shaft sleeve fixedly connected inside the hydraulic motor shell, a first bearing, a second bearing and a third bearing are arranged in the shaft sleeve, a first gear shaft is supported and installed on the first bearing, a second gear shaft is supported and installed on the second bearing, a third gear shaft is supported and installed on the third bearing, a first gear is fixedly connected to the first gear shaft, a second gear is fixedly connected to the second gear shaft, a third gear is fixedly connected to the third gear shaft, the second gear is respectively meshed with the first gear and the third gear, and the second gear shaft is fixedly connected with an output shaft of the brushless direct current motor; the hydraulic motor shell is provided with an upper oil outlet and a lower oil inlet which are positioned between a first gear and a second gear, and a lower oil outlet and an upper oil inlet which are positioned between the second gear and a third gear, the circulation valve is arranged on the upper oil outlet, the compression valve is arranged on the lower oil inlet, the compensation valve is arranged on the lower oil outlet, and the expansion valve is arranged on the upper oil inlet; the cavity that is located between lower bushing, lower guide holder and the piston cylinder lower extreme cap in the piston cylinder is the electric control chamber, be provided with control box and super capacitor group in the electric control chamber, the actuator controller sets up in the control box, still be provided with rectifier bridge, three-phase full-bridge inverter circuit, DC/DC converting circuit and motor drive in the control box to and first relay, second relay, third relay and fourth relay, the input termination of actuator controller has the road surface irregularity displacement sensor who is used for carrying out real-time detection to road surface irregularity displacement, the unsprung mass displacement sensor who is used for carrying out real-time detection to unsprung mass displacement, the spring loaded mass displacement sensor who is used for carrying out real-time detection to spring loaded mass displacement, the piston rod speedtransmitter who is used for carrying out real-time detection to the speed of piston rod and the hydraulic oil speedtransmitter who is used for carrying out real-time detection to the velocity of flow of hydraulic oil, the first relay is connected between the brushless direct current motor and the rectifier bridge, the second relay is connected between the brushless direct current motor and the three-phase full-bridge inverter circuit, the third relay is connected between the rectifier bridge and the DC/DC conversion circuit, the fourth relay is connected between the three-phase full-bridge inverter circuit and the DC/DC conversion circuit, and the super capacitor bank is connected with the DC/DC conversion circuit; the motor driver, the three-phase full-bridge inverter circuit, the first relay, the second relay, the third relay and the fourth relay are all connected with the output end of the actuator controller, and the brushless direct current motor is connected with the output end of the motor driver.

The hydro-electric integrated self-powered active suspension actuator is characterized in that: the upper end cover of the piston cylinder is connected to the upper part of the piston cylinder in a threaded mode, and the lower end cover of the piston cylinder is connected to the lower part of the piston cylinder in a threaded mode.

The hydro-electric integrated self-powered active suspension actuator is characterized in that: and the upper ear ring is fixedly connected with a dust cover covering the upper part of the piston cylinder.

The hydro-electric integrated self-powered active suspension actuator is characterized in that: the lower end of the upper piston rod is welded with the piston, the upper end of the lower piston rod is welded with the piston, and the upper end of the upper piston rod penetrates out of the upper end cover of the piston cylinder to be welded with the upper earring.

The hydro-electric integrated self-powered active suspension actuator is characterized in that: and a third sealing ring is arranged between the piston cylinder and the piston.

The hydro-electric integrated self-powered active suspension actuator is characterized in that: the first bearing, the second bearing and the third bearing are ball bearings, and the number of the first bearings, the number of the second bearings and the number of the third bearings are two.

The hydro-electric integrated self-powered active suspension actuator is characterized in that: the first gear is fixedly connected to the first gear shaft through a first key, the second gear is fixedly connected to the second gear shaft through a second key, and the third gear is fixedly connected to the third gear shaft through a third key; and the second gear shaft is fixedly connected with an output shaft of the brushless direct current motor through a coupler.

The hydro-electric integrated self-powered active suspension actuator is characterized in that: the lower piston rod is of a hollow structure, and a connecting wire when the brushless direct current motor is connected with the output end of the motor driver penetrates through the lower piston rod of the hollow structure.

The invention also provides a control method of the hydro-electric integrated self-powered active suspension actuator, which has simple method steps and convenient realization, can ensure that the suspension actuator is in the optimal vibration damping state, and better improves the smoothness and the operation stability of vehicle running, and is characterized by comprising the following steps:

step I, a road surface irregularity displacement sensor detects road surface irregularity displacement in real time, an unsprung mass displacement sensor detects unsprung mass displacement in real time, a sprung mass displacement sensor detects sprung mass displacement in real time, a piston rod speed sensor detects the speed of a piston rod in real time, a hydraulic oil speed sensor detects the flow rate of hydraulic oil in real time, and an actuator controller periodically samples the road surface irregularity displacement, the unsprung mass displacement, the sprung mass displacement, the speed of a lower piston rod and the flow rate of the hydraulic oil respectively;

step II, firstly, the actuator controller calls an LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator during the ith sampling_iThe actuator controller is then based on the formula P_i＝U_i·V_iCalculating to obtain the instantaneous power value P of the suspension actuator at the ith sampling_iWherein V is_iThe value of i is a natural number which is not 0 for the speed of the lower piston rod obtained by the ith sampling; then, the actuator controller judges the instantaneous power value P of the suspension actuator at the ith sampling_iPositive and negative of (b), when P is_iWhen the load is negative, the actuator controller does not output a control signal to the brushless direct current motor, the suspension actuator works in an energy feedback mode, and the specific working process is as follows: the vehicle body vibrates to drive the upper piston rod to move, the upper piston rod drives the piston and the lower piston rod to move, when the upper piston rod moves upwards, the piston moves upwards, the flow valve is closed under the action of hydraulic oil in the upper cavity of the piston cylinder, the expansion valve is opened, the hydraulic oil enters the upper oil inlet through the expansion valve, the second gear is pushed to rotate anticlockwise under the action of the hydraulic oil, the third gear rotates clockwise, the hydraulic oil flows into the lower cavity of the piston cylinder through the lower oil outlet jacking compensation valve, the second gear rotates anticlockwise to drive the second gear shaft to rotate, the second gear shaft rotates to drive the brushless direct current motor to rotate to generate electricity, at the moment, the actuator controller outputs signals to control the first relay and the third relay to be electrified, the second relay and the fourth relay are not electrified, so that the electric energy generated by the brushless direct current motor converts alternating current into unidirectional direct current through the rectifier bridge, then the alternating current is boosted through the DC/DC conversion circuit and then, the recovery of vibration energy is realized; when the upper piston rod moves downwards, the pistonThe hydraulic oil enters a lower oil inlet through the compression valve, the second gear is pushed to rotate anticlockwise under the action of the hydraulic oil, the first gear rotates clockwise, the hydraulic oil flows into an upper cavity of the piston cylinder through an upper oil outlet jacking circulation valve, the second gear rotates anticlockwise to drive a second gear shaft to rotate, the second gear shaft rotates to drive the brushless direct current motor to rotate to generate electricity, at the moment, the actuator controller outputs signals to control the first relay and the third relay to be electrified, the second relay and the fourth relay are not electrified, so that electric energy generated by the brushless direct current motor is converted into unidirectional direct current through a rectifier bridge, and then the unidirectional direct current is boosted through a DC/DC conversion circuit and then is charged into the super capacitor bank, and the recovery of vibration energy is realized;

when P is present_iIn order to be correct, firstly, the actuator controller calls an LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator during the ith sampling_iThe actuator controller further calculates a hydraulic pressure balance equation of the suspension actuator according to the ith sampling timeDeducing the pressure difference of the oil inlet and the oil outlet of the hydraulic motor module when the ith sampling is obtainedWherein the ith sampling of the hydraulic total pressure loss of the suspension actuatorA is the cross-sectional area of the piston, zeta is the local resistance coefficient, rho is the density of the hydraulic oil, v_iThe flow rate of the hydraulic oil during the ith sampling is shown; then, the actuator controller firstly uses the formulaCalculating to obtain the output torque of the second gear shaft of the hydraulic motor moduleWherein q is the displacement of the hydraulic motor module, η_mFor the mechanical efficiency of the hydraulic motor module, the actuator controller is then based on the formulaCalculating to obtain a torque control signal which needs to be output to the brushless direct current motor during the ith samplingThen, the actuator controller controls the actuator according to the torque control signalOutput PWM control signal control three-phase full-bridge inverter circuit work to output signal controls second relay and fourth relay circular telegram, and first relay and third relay do not circular telegram, and super capacitor bank discharges this moment, and output voltage supplies power for brushless DC motor through three-phase full-bridge inverter circuit after stepping up through DC/DC converting circuit, the integrated form of liquid electricity is from energy supply initiative suspension actuator work under the initiative mode, and specific course of work is: when a downward active output force needs to be provided, the actuator controller drives the brushless direct current motor to rotate anticlockwise through the motor driver, the brushless direct current motor drives the second gear shaft to rotate anticlockwise, the second gear shaft rotates anticlockwise to drive the second gear to rotate anticlockwise, the second gear rotates anticlockwise to drive the first gear and the third gear to rotate clockwise, hydraulic oil flows into the upper piston cylinder cavity from the lower piston cylinder cavity through the compression valve and the circulation valve, the oil pressure of the upper piston cylinder cavity rises, the piston is pushed to move downwards, the piston moves downwards to drive the upper piston rod to move downwards, so that a downward active control force is provided and is transmitted to the vehicle body, and active control of the suspension actuator is achieved;

when the ware controller passes through motor drive brushless DC motor clockwise rotation, brushless DC motor drives second gear shaft clockwise rotation, and second gear shaft clockwise rotation drives second gear clockwise rotation, and second gear clockwise rotation drives first gear and third gear anticlockwise rotation, hinders hydraulic oil and flows to increase damping coefficient improves the damping force, realizes suspension actuator's semi-active control.

The above method is characterized in that: in the step II, the actuator controller calls an LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator during the ith sampling_iThe specific process comprises the following steps:

step one, the actuator controller is used for controlling the actuator according to the spring load mass m of the single wheel of the vehicle_sVehicle single-wheel unsprung mass m_uSuspension spring stiffness k_sTire stiffness k_tInherent damping coefficient c of vehicle suspension system_sIdeal active control force U of the suspension actuator at the ith sampling_iUnsprung mass displacement x₁And sprung mass displacement x₂(ii) a Taking the road surface unevenness displacement z as input excitation; using Newton's law of motion, establishingThe differential equation of the vehicle running vibration is as follows:

$\left\{\begin{array}{c}{m}_s{\stackrel{\·\·}{x}}_2+k_s(x_2-x_1)+c_s({\stackrel{\·}{x}}_2-{\stackrel{\·}{x}}_1)=U_i\\ m_u{\stackrel{\·\·}{x}}_1-k_s(x_2-x_1)-c_s({\stackrel{\·}{x}}_2-{\stackrel{\·}{x}}_1)+k_t(x_1-z)=-U_i\end{array}\right.;$

step two, the actuator controller establishes a vehicle vibration state equation as follows:

$\left\{\begin{array}{c}\stackrel{\·}{X}=AX+{\mathrm{BU}}_i+G\stackrel{\·}{z}\\ Y=CX+{\mathrm{DU}}_i\end{array}\right.$

thirdly, the actuator controller selects the vibration speed of the vehicle bodyWheel vibration speedDynamic deflection (x) of suspension₂-x₁) Dynamic deformation of tire (x)₁-z) is a state variable, resulting inThe specific forms of the system matrix A, the control matrix B and the disturbance input matrix G are obtained as follows:

$A=\left[\begin{array}{cccc}0& 1& 0& -1\\ -\frac{k_s}{m_s}& -\frac{c_s}{m_s}& 0& \frac{c_s}{m_s}\\ 0& 0& 0& 1\\ \frac{k_s}{m_u}& \frac{c_s}{m_u}& -\frac{k_t}{m_u}& -\frac{c_s}{m_u}\end{array}\right],B=\left[\begin{array}{c}0\\ \frac{1}{m_s}\\ 0\\ -\frac{1}{m_u}\end{array}\right],G=\left[\begin{array}{c}0\\ 0\\ -1\\ 0\end{array}\right]$

fourthly, the actuator controller selects the vertical acceleration of the vehicle bodyDynamic deflection (x) of suspension₂-x₁) Dynamic deformation of tire (x)₁-z) as an output variable, obtainingThe output matrix C and the transfer matrix D are then of the form:

$C=\left[\begin{array}{cccc}-\frac{k_s}{m_s}& -\frac{c_s}{m_s}& 0& \frac{c_s}{m_s}\\ 1& 0& 0& 0\\ 0& 0& 1& 0\end{array}\right],D=\left[\begin{array}{c}{\frac{1}{m}}_s\\ 0\\ 0\end{array}\right]$

step five, the actuator controller outputs an equation Y which is CX + DU_iSubstituting into formulaIn the method, the obtained quadratic performance indexes are as follows:and has:Q＝C^TqC，N＝C^TqD，R＝r+D^TqD; wherein t is time, q₁As a vehicle body acceleration weighting factor, q₂Weighting factor q for dynamic deflection of suspension₃The dynamic deformation weighting coefficient of the tire, and r is an energy consumption weighting coefficient; q is a semi-positive definite symmetric weighting matrix of the state variable, N is a weighting matrix of the relevance of the two variables, and R is a positive definite symmetric weighting matrix of the control variable;

step six, the actuator controller obtains the optimal control feedback gain matrix K at the ith sampling time by applying an LQR function provided in Matlab software according to the system matrix A and the control matrix B determined in the step three and the weighting matrix Q, the weighting matrix N and the weighting matrix R determined in the step five_i；

Seventhly, the actuator controller is controlled according to a formulaCalculating to obtain the suspension dynamic deflection (x) during the ith sampling₂-x₁)ⁱAccording to the formulaCalculating to obtain the sprung mass velocity at the ith samplingAccording to the formulaCalculating to obtain the tire dynamic displacement (x) at the ith sampling₁-z)ⁱAccording to the formulaCalculating to obtain the unsprung mass velocity at the ith samplingWherein,for the sprung mass displacement obtained for the ith sample,for the sprung mass displacement obtained for the i-1 th sample,for the unsprung mass displacement obtained for the ith sample,unsprung mass displacement, z, obtained for sample i-1ⁱThe displacement of the road surface unevenness obtained by the ith sampling is obtained, and t is time;

step eight, the actuator controller determines the suspension dynamic deflection (x) at the ith sampling according to the step seven₂-x₁)ⁱSpeed of sprung massDynamic displacement (x) of tyre₁-z)ⁱAnd unsprung mass velocityAccording to the formulaObtaining the state variable X at the ith sampling_i；

Ninthly, the actuatorThe controller feeds back the gain matrix K according to the optimal control at the ith sampling determined in the step six_iAnd the state variable X at the ith sampling determined in the step eight_iAccording to the formulaCalculating to obtain the ideal optimal active control force U of the suspension actuator during the ith sampling_i。

Compared with the prior art, the invention has the following advantages:

1. the hydro-electric integrated self-powered active suspension actuator has the advantages of simple structure, novel and reasonable design, convenience in implementation, low cost and high integration degree, and lays a foundation for market popularization.

2. The invention provides a novel suspension actuator control strategy, wherein an actuator controller is used as a coordination switching point according to the positive and negative of an instantaneous power value, when the electric energy generated by a system is enough to supply the system to operate in an energy feedback mode, redundant electric energy is recovered into a super capacitor, when the system needs to consume the electric energy, the system operates in an active mode, and the electric energy recovered into the super capacitor in the energy feedback mode is supplied to the active mode, so that the self-energy supply of the system is realized on the premise of ensuring the driving smoothness of a vehicle.

3. The hydro-electric integrated self-powered active suspension actuator can realize self-power supply under the condition of meeting the energy balance condition, namely when the energy fed back under the energy feedback mode is more than or equal to the energy consumed under the active control model, the average power of the suspension is a negative value or zero, which is the energy balance condition for realizing the self-power supply function of the active suspension; the energy consumed and recovered by the system is determined by the actual instantaneous power P_iAnd (3) integrating the time t, namely the total energy of the final charge and discharge of the system to the super capacitor is as follows:when the vehicle runs for a period of time under a certain road condition, the system can realize self-operation when the system meets the energy balance condition W less than or equal to 0The energy supply and the redundant energy are used by other electric equipment of the automobile.

4. When the hydro-electric integrated self-powered active suspension actuator is used and works in an energy feedback mode, no matter the suspension actuator makes a stretching stroke or a compression stroke, due to the reasonable arrangement of the one-way valve group and the adoption of the principle of the three-gear externally-meshed cycloid hydraulic motor, the second gear always makes anticlockwise rotation and drives the second gear shaft to always rotate anticlockwise, so that the brushless direct current motor always rotates in one direction to generate electricity, a large amount of inertia loss is avoided, the power generation efficiency is improved, the service life of the brushless direct current motor is prolonged, and the working stability and reliability of the suspension actuator can be improved.

5. The hydro-electric integrated self-powered active suspension actuator has high working stability and reliability, is not easy to break down, and does not need frequent maintenance and repair.

6. When the hydro-electric integrated self-powered active suspension actuator is used, when a fault occurs, the system works in a passive mode, the function of the actuator is the same as that of the traditional common suspension, the damping force is viscous damping force, and the phenomenon that the driving smoothness and the operation stability of a vehicle are deteriorated due to the fact that a damping system is broken down caused by system failure is prevented.

7. The rigidity and the pretightening force of the spring of the expansion valve are larger than those of the compression valve, and under the action of the same oil pressure, the sum of the channel sectional areas of the expansion valve and the corresponding normally open gap is smaller than that of the compression valve and the corresponding normally open gap, so that the damping force generated by the suspension actuator in the expansion stroke is larger than that generated in the compression stroke, the vibration damping effect of the suspension actuator is better exerted, and the running smoothness of a vehicle is better improved.

8. The method for controlling the hydro-electric integrated self-powered active suspension actuator has the advantages of simple steps, convenient realization, and capability of enabling the suspension actuator to be in the optimal vibration damping state and better improving the smoothness and the operation stability of vehicle running.

9. The invention has strong practicability and good use effect, and is convenient for market popularization.

In conclusion, the suspension actuator is novel and reasonable in design, convenient to implement and low in cost, can enable the suspension actuator to be in the optimal vibration damping state, improves the smoothness and the operation stability of vehicle running better, and is high in practicability, good in using effect and convenient to popularize in the market.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural diagram of an electrohydraulic integrated self-powered active suspension actuator according to the present invention.

Fig. 2 is a longitudinal sectional view of the piston of the present invention.

Fig. 3 is a transverse cross-sectional view of the piston of the present invention.

FIG. 4 is a schematic diagram of the electrical connections between the actuator controller and other components of the actuator controller of the present invention.

Description of reference numerals:

1-upper earring; 2-a dust cover; 3-upper end cover of piston cylinder;

4-1-oil sealing; 4-2-lower oil seal; 5-1-a first seal ring;

5-2-a second seal ring; 6-1-upper snap ring; 6-2-lower snap ring;

7-1-upper guide seat; 7-2-lower guide seat; 8-1-upper liner;

8-2-lower liner; 9-upper piston rod; 10-a piston cylinder;

11-piston cylinder upper chamber; 12-a piston; 13-hydraulic oil;

14-piston cylinder lower chamber; 15-lower piston rod; 16-a fourth relay;

17-a motor driver; 18-a control box; 19-piston cylinder lower end cover;

20-lower earring; 21-1-a road surface irregularity displacement sensor;

21-2-unsprung mass displacement sensor; 21-3-sprung mass displacement sensor;

21-4-piston rod speed sensor; 21-5-hydraulic oil speed sensor;

22-a supercapacitor bank; 23-a flow-through valve; 24-a first gear;

25-a third seal ring; 26-a compression valve; 27-a compensation valve;

28-a second gear; 29-a third gear; 30-a stretch valve;

31-a hydraulic motor housing; 32-1-a first bearing; 32-2-second bearing;

32-3-a third bearing; 33-shaft sleeve; 34-1-first bond;

34-2-second bond; 34-3-third bond; 35-a first gear shaft;

36-a brushless dc motor; 37-a coupler; 38-second gear shaft;

39-third gear shaft; 41-actuator controller; 42-a rectifier bridge;

43-three-phase full-bridge inverter circuit; 44-DC/DC conversion circuit;

45-oil outlet; 46-a lower oil inlet; 47-lower oil outlet;

48-upper oil inlet; 49-electrically controlled cavity; 50-a first relay;

51-a second relay; 52-third relay.

Detailed Description

As shown in fig. 1, 2, 3 and 4, the hydro-electric integrated self-powered active suspension actuator of the present invention comprises an actuator body and an actuator controller 41, wherein the actuator body comprises a piston cylinder 10, a piston 12, an upper piston rod 9, a lower piston rod 15, an upper ear ring 1 and a lower ear ring 20, an upper end cover 3 of the piston cylinder 10 is connected to an upper portion of the piston cylinder 10, a lower end cover 19 of the piston cylinder 10 is connected to a lower portion of the piston cylinder 10, the lower ear ring 20 is connected to the lower end cover 19 of the piston cylinder, the piston 12 is disposed at a middle upper portion of the piston cylinder 10, a lower end of the upper piston rod 9 is connected to the piston 12, an upper end of the lower piston rod 15 is connected to the piston 12, an upper end of the upper piston rod 9 penetrates through the outer portion of the upper end cover 3 of the piston cylinder to be connected to the upper ear ring 1, an upper bushing 8-1 is fixedly connected to an upper portion of the piston cylinder 10, and a snap-on upper piston rod 9 is An upper guide seat 7-1 for guiding the up-and-down movement of the upper piston rod 9, an upper oil seal 4-1 sleeved on the upper piston rod 9 is arranged between the upper end cover 3 of the piston cylinder and the upper guide seat 7-1, and a first sealing ring 5-1 positioned between the upper end cover 3 of the piston cylinder and an upper bushing 8-1 is sleeved on the upper oil seal 4-1; the middle lower part in the piston cylinder 10 is fixedly connected with a lower bushing 8-2, a lower guide seat 7-2 which is sleeved on the lower piston rod 15 and used for guiding the up-and-down movement of the lower piston rod 15 is connected in the lower bushing 8-2 in a clamping manner through a lower clamping ring 6-2, a lower oil seal 4-2 sleeved on the lower piston rod 15 is arranged at the lower part of the lower guide seat 7-2, and a second sealing ring 5-2 positioned at the lower part of the lower bushing 8-2 is sleeved on the lower oil seal 4-2; a cavity positioned among the upper bushing 8-1, the upper guide seat 7-1 and the piston 12 in the piston cylinder 10 is a piston cylinder upper cavity 11, a cavity positioned among the lower bushing 8-2, the lower guide seat 7-2 and the piston 12 in the piston cylinder 10 is a piston cylinder lower cavity 14, and hydraulic oil 13 is arranged in both the piston cylinder upper cavity 11 and the piston cylinder lower cavity 14; a check valve set, a hydraulic motor module and a brushless direct current motor 36 are embedded in the piston 12, the check valve set comprises a circulation valve 23, a compression valve 26, a compensation valve 27 and an extension valve 30, the hydraulic motor module comprises a hydraulic motor shell 31 and a shaft sleeve 33 fixedly connected inside the hydraulic motor shell 31, a first bearing 32-1, a second bearing 32-2 and a third bearing 32-3 are arranged in the shaft sleeve 33, a first gear shaft 35 is supported and installed on the first bearing 32-1, a second gear shaft 38 is supported and installed on the second bearing 32-2, a third gear shaft 39 is supported and installed on the third bearing 32-3, a first gear 24 is fixedly connected on the first gear shaft 35, a second gear 28 is fixedly connected on the second gear shaft 38, and a third gear 29 is fixedly connected on the third gear shaft 39, the second gear 28 is meshed with the first gear 24 and the third gear 29 respectively, and the second gear shaft 38 is fixedly connected with an output shaft of the brushless direct current motor 36; the hydraulic motor shell 31 is provided with an upper oil outlet 45 and a lower oil inlet 46 which are positioned between the first gear 24 and the second gear 28, and a lower oil outlet 47 and an upper oil inlet 48 which are positioned between the second gear 28 and the third gear 29, the flow valve 23 is arranged on the upper oil outlet 45, the compression valve 26 is arranged on the lower oil inlet 46, the compensation valve 27 is arranged on the lower oil outlet 47, and the extension valve 30 is arranged on the upper oil inlet 48; the cavity between the lower bushing 8-2, the lower guide seat 7-2 and the lower end cover 19 of the piston cylinder 10 is an electric control cavity 49, a control box 18 and a super capacitor set 22 are arranged in the electric control cavity 49, the actuator controller 41 is arranged in the control box 18, a rectifier bridge 42, a three-phase full-bridge inverter circuit 43, a DC/DC conversion circuit 44 and a motor driver 17 are further arranged in the control box 18, a first relay 50, a second relay 51, a third relay 52 and a fourth relay 16 are further arranged in the control box 18, the input end of the actuator controller 41 is connected with a road surface irregularity displacement sensor 21-1 for detecting road surface irregularity displacement in real time, an unsprung mass displacement sensor 21-2 for detecting unsprung mass displacement in real time, and a sprung mass displacement sensor 21-3 for detecting sprung mass displacement in real time, The system comprises a piston rod speed sensor 21-4 for detecting the speed of a piston rod 15 in real time and a hydraulic oil speed sensor 21-5 for detecting the flow rate of hydraulic oil 13 in real time, wherein a first relay 50 is connected between a brushless direct current motor 36 and a rectifier bridge 42, a second relay 51 is connected between the brushless direct current motor 36 and a three-phase full-bridge inverter circuit 43, a third relay 52 is connected between the rectifier bridge 42 and a DC/DC conversion circuit 44, a fourth relay 16 is connected between the three-phase full-bridge inverter circuit 43 and the DC/DC conversion circuit 44, and a super capacitor bank 22 is connected with the DC/DC conversion circuit 44; the motor driver 17, the three-phase full-bridge inverter circuit 43, the first relay 50, the second relay 51, the third relay 52 and the fourth relay 16 are all connected with the output end of the actuator controller 41, and the brushless direct current motor 36 is connected with the output end of the motor driver 17.

In this embodiment, the piston cylinder upper end cap 3 is screwed on the upper portion of the piston cylinder 10, and the piston cylinder lower end cap 19 is screwed on the lower portion of the piston cylinder 10.

In this embodiment, as shown in fig. 1, a dust cover 2 covering the upper portion of the piston cylinder 10 is fixedly connected to the upper ear ring 1. In specific implementation, the dust cover 2 is welded with the upper earring 1.

In this embodiment, the lower end of the upper piston rod 9 is welded to the piston 12, the upper end of the lower piston rod 15 is welded to the piston 12, and the upper end of the upper piston rod 9 penetrates through the outer portion of the upper end cover 3 of the piston cylinder and is welded to the upper earring 1.

In this embodiment, as shown in fig. 1 and 2, a third seal ring 25 is disposed between the piston cylinder 10 and the piston 12.

In this embodiment, the first bearing 32-1, the second bearing 32-2 and the third bearing 32-3 are all ball bearings, and the number of the first bearings 32-1, the number of the second bearings 32-2 and the number of the third bearings 32-3 are all two.

In this embodiment, as shown in fig. 4, the first gear 24 is fixedly connected to the first gear shaft 35 by a first key 34-1, the second gear 28 is fixedly connected to the second gear shaft 38 by a second key 34-2, and the third gear 29 is fixedly connected to the third gear shaft 39 by a third key 34-3; the second gear shaft 38 is fixedly connected with the output shaft of the brushless dc motor 36 through a coupling 37.

In this embodiment, the lower piston rod 15 has a hollow structure, and a connection line when the brushless dc motor 36 is connected to the output end of the motor driver 17 passes through the lower piston rod 15 having the hollow structure.

The invention discloses a control method of a liquid-electricity integrated self-powered active suspension actuator, which comprises the following steps of:

step I, a road surface irregularity displacement sensor 21-1 detects road surface irregularity displacement in real time, an unsprung mass displacement sensor 21-2 detects unsprung mass displacement in real time, a sprung mass displacement sensor 21-3 detects sprung mass displacement in real time, a piston rod speed sensor 21-4 detects the speed of a piston rod 15 in real time, a hydraulic oil speed sensor 21-5 detects the flow rate of hydraulic oil 13 in real time, and an actuator controller 41 periodically samples the road surface irregularity displacement, the unsprung mass displacement, the sprung mass displacement, the speed of a lower piston rod 15 and the flow rate of the hydraulic oil 13 respectively; in specific implementation, the sampling period is 0.25 s-1 s;

step II, firstly, the actuator controller 41 calls the LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator during the ith sampling_iThe actuator controller 41 then calculates the formula P_i＝U_i·V_iCalculating to obtain the instantaneous power value P of the suspension actuator at the ith sampling_iWherein V is_iThe value of i is a natural number which is not 0 for the speed of the lower piston rod 15 obtained by the ith sampling; then, the actuator controller 41 determines the instantaneous power value P of the suspension actuator at the ith sampling time_iPositive and negative of (b), when P is_iWhen the current is negative, the actuator controller 41 does not output a control signal to the brushless dc motor 36, and the suspension actuator operates in the energy feedback mode, which specifically includes: the vibration of the vehicle body drives the upper piston rod 9 to move, the upper piston rod 9 drives the piston 12 and the lower piston rod 15 to move, when the upper piston rod 9 moves upwards (namely, when the suspension actuator makes a stretching stroke), the piston 12 moves upwards, under the action of hydraulic oil 13 in the upper cavity 11 of the piston cylinder, the circulating valve 23 is closed, the stretching valve 30 is opened, the hydraulic oil 13 enters the upper oil inlet 48 through the stretching valve 30, and under the action of the hydraulic oil 13, the second gear 28 is pushed to perform inverse motionThe hour hand rotates, the third gear 29 rotates clockwise, the hydraulic oil 13 flows into the lower cavity 14 of the piston cylinder through the lower oil outlet 47 to jack the compensating valve 27, the second gear 28 rotates counterclockwise to drive the second gear shaft 38 to rotate, the second gear shaft 38 rotates and drives the brushless direct current motor 36 to rotate and generate power through the coupler 37, at this time, the actuator controller 41 outputs signals to control the first relay 50 and the third relay 52 to be electrified, the second relay 51 and the fourth relay 16 are not electrified, so that the electric energy generated by the brushless direct current motor 36 is converted into unidirectional direct current through the rectifier bridge 42, the alternating current is boosted through the DC/DC conversion circuit 44 and then is charged into the super capacitor bank 22, and the recovery of vibration energy is realized; when the upper piston rod 9 moves downwards (i.e. when the suspension actuator performs a compression stroke), the piston 12 moves downwards, the compensation valve 27 is closed under the action of the hydraulic oil 13 in the lower piston cylinder cavity 14, the compression valve 26 is opened, the hydraulic oil 13 enters the lower oil inlet 46 through the compression valve 26, the second gear 28 is pushed to rotate counterclockwise under the action of the hydraulic oil 13, the first gear 24 rotates clockwise, the hydraulic oil 13 flows into the upper piston cylinder cavity 11 through the upper oil outlet 45 by pushing the circulation valve 23, the second gear shaft 38 rotates counterclockwise by the rotation of the second gear 28, the second gear shaft 38 rotates and drives the brushless dc motor 36 to rotate and generate electricity through the coupling 37, at this time, the actuator controller 41 outputs a signal to control the first relay 50 and the third relay 52 to be energized, the second relay 51 and the fourth relay 16 are not energized, so that the electric energy generated by the brushless dc motor 36 converts alternating current into direct current through the rectifier bridge 42, the vibration energy is boosted by the DC/DC conversion circuit 44 and then charged to the super capacitor bank 22, so that the recovery of the vibration energy is realized; in the above process, no matter the suspension actuator performs the extension stroke or the compression stroke, due to the reasonable arrangement of the check valve set, the second gear 28 always rotates counterclockwise to drive the second gear shaft 38 to rotate counterclockwise all the time, so that the brushless dc motor 36 always rotates in one direction to generate power, thereby avoiding a great amount of inertia loss caused by repeated forward and reverse rotation of the brushless dc motor 36, improving the power generation efficiency, and prolonging the service life of the brushless dc motor 36;

when P is present_iIs positive (i.e. P)_i> 0), first, the actuator controller41, firstly calling an LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator during the ith sampling_iThe actuator controller 41 further calculates the hydraulic pressure balance equation of the suspension actuator at the ith sampling timeDeducing the pressure difference of the oil inlet and the oil outlet of the hydraulic motor module when the ith sampling is obtained(i.e., the pressure difference between the upper oil inlet 48 and the upper oil outlet 45, or the pressure difference between the lower oil inlet 46 and the lower oil outlet 47), wherein the hydraulic total pressure loss of the suspension actuator is sampled the ith timeA is the cross-sectional area of the piston 12, ζ is the local drag coefficient, ρ is the density of the hydraulic oil 13, v_iThe flow rate of the hydraulic oil 13 at the ith sampling; next, the actuator controller 41 first calculates the formulaCalculating the output torque of the second gear shaft 38 of the hydraulic motor moduleWherein q is the displacement of the hydraulic motor module, η_mFor the mechanical efficiency of the hydraulic motor module, the actuator controller 41 then follows the formulaCalculating the torque control signal to be output to the brushless DC motor 36 during the ith sampling(since the brushless DC motor 36 is fixedly connected to the second gear shaft 38 via the coupling 37, the brushless DC motor 36 is loaded with torqueOutput torque with the second gear shaft 38Equal), the actuator controller 41 then controls the torque according to the torque control signalOutputting a PWM control signal to control a three-phase full-bridge inverter circuit 43 to work and outputting a signal to control a second relay 51 and a fourth relay 16 to be electrified, wherein a first relay 50 and a third relay 52 are not electrified, at the moment, a super capacitor bank 22 discharges electricity, an output voltage is boosted by a DC/DC conversion circuit 44 and then supplies power to a brushless direct current motor 36 through the three-phase full-bridge inverter circuit 43, the hydraulic-electric integrated self-powered active suspension actuator works in an active mode, specifically, in the working process, when downward active output force needs to be provided, an actuator controller 41 drives the brushless direct current motor 36 to rotate anticlockwise through a motor driver 17, the brushless direct current motor 36 drives a second gear shaft 38 to rotate anticlockwise, the second gear shaft 38 rotates anticlockwise to drive a second gear 28 to rotate anticlockwise, the second gear 28 rotates anticlockwise to drive a first gear 24 and a third gear 29 to rotate, hydraulic oil 13 flows into a piston cylinder upper cavity 11 through a compression valve 26 and a piston cylinder circulation 14, the piston cylinder 11 raises oil pressure to push the piston 12 to move downwards, the piston rod 9 moves downwards, and then the piston rod 354 controls the suspension to perform active suspension actuator to control^-6mL/r, said η_mIs 0.85.

When the actuator controller 41 drives the brushless dc motor 36 to rotate clockwise through the motor driver 17, the brushless dc motor 36 drives the second gear shaft 38 to rotate clockwise, the second gear shaft 38 drives the second gear 28 to rotate clockwise, the second gear 28 drives the first gear 24 and the third gear 29 to rotate counterclockwise, and hydraulic oil 13 is blocked to flow, so that the damping coefficient is increased, the damping force is improved, and the semi-active control of the suspension actuator is realized.

In this embodiment, in step II, the actuator controller 41 invokes the LQG optimal control module to analyze and process the sampled signal, so as to obtain the ideal active control force U of the suspension actuator at the sampling time of the ith time_iThe specific process comprises the following steps:

step one, the actuator controller 41 carries out the control according to the spring load mass m of the single wheel of the vehicle_sVehicle single-wheel unsprung mass m_uSuspension spring stiffness k_sTire stiffness k_tInherent damping coefficient c of vehicle suspension system_sIdeal active control force U of the suspension actuator at the ith sampling_iUnsprung mass displacement x₁And sprung mass displacement x₂(ii) a Taking the road surface unevenness displacement z as input excitation; using Newton's law of motion, establishingThe differential equation of the vehicle running vibration is as follows:

$\left\{\begin{array}{c}{m}_s{\stackrel{\·\·}{x}}_2+k_s(x_2-x_1)+c_s({\stackrel{\·}{x}}_2-{\stackrel{\·}{x}}_1)=U_i\\ m_u{\stackrel{\·\·}{x}}_1-k_s(x_2-x_1)-c_s({\stackrel{\·}{x}}_2-{\stackrel{\·}{x}}_1)+k_t(x_1-z)=-U_i\end{array}\right.;$

step two, the actuator controller 41 establishes a vehicle vibration state equation as follows:

$\left\{\begin{array}{c}\stackrel{\·}{X}=AX+{\mathrm{BU}}_i+G\stackrel{\·}{z}\\ Y=CX+{\mathrm{DU}}_i\end{array}\right.$

thirdly, the actuator controller 41 selects the vibration speed of the vehicle bodyWheel vibration speedDynamic deflection (x) of suspension₂-x₁) Dynamic deformation of tire (x)₁-z) is a state variable, resulting inThe specific forms of the system matrix A, the control matrix B and the disturbance input matrix G are obtained as follows:

$A=\left[\begin{array}{cccc}0& 1& 0& -1\\ -\frac{k_s}{m_s}& -\frac{c_s}{m_s}& 0& \frac{c_s}{m_s}\\ 0& 0& 0& 1\\ \frac{k_s}{m_u}& \frac{c_s}{m_u}& -\frac{k_t}{m_u}& -\frac{c_s}{m_u}\end{array}\right],B=\left[\begin{array}{c}0\\ \frac{1}{m_s}\\ 0\\ -\frac{1}{m_u}\end{array}\right],G=\left[\begin{array}{c}0\\ 0\\ -1\\ 0\end{array}\right]$

step four, the actuator controller 41 selects the vertical acceleration of the vehicle bodyDynamic deflection (x) of suspension₂-x₁) Dynamic deformation of tire (x)₁-z) as an output variable, obtainingThe output matrix C and the transfer matrix D are then of the form:

$C=\left[\begin{array}{cccc}-\frac{k_s}{m_s}& -\frac{c_s}{m_s}& 0& \frac{c_s}{m_s}\\ 1& 0& 0& 0\\ 0& 0& 1& 0\end{array}\right],D=\left[\begin{array}{c}{\frac{1}{m}}_s\\ 0\\ 0\end{array}\right]$

step five, the actuator controller 41 outputs the output equation Y ═ CX + DU_iSubstituting into formulaIn the method, the obtained quadratic performance indexes are as follows:and has:Q＝C^TqC，N＝C^TqD，R＝r+D^TqD; wherein t is time, q₁As a vehicle body acceleration weighting factor, q_２Weighting factor q for dynamic deflection of suspension₃The dynamic deformation weighting coefficient of the tire, and r is an energy consumption weighting coefficient; q is a semi-positive definite symmetric weighting matrix of the state variable, N is a weighting matrix of the relevance of the two variables, and R is a positive definite symmetric weighting matrix of the control variable; in specific practice, q is₁＝1.2×10⁵，q₂＝1.65×10⁸，q₃＝9.5×10⁹，r＝1；

Step six, the actuator controller 41 obtains the optimal control feedback gain matrix K at the ith sampling time by applying the LQR function provided in Matlab software according to the system matrix A and the control matrix B determined in the step three and the weighting matrix Q, the weighting matrix N and the weighting matrix R determined in the step five_i；

Step seven, the actuator controller 41 according to the formulaCalculating to obtain the suspension dynamic deflection (x) during the ith sampling_２-x₁)ⁱAccording to the formulaCalculating to obtain the sprung mass velocity at the ith samplingAccording to the formulaCalculating to obtain the tire dynamic displacement (x) at the ith sampling₁-z)ⁱAccording to the formulaCalculating to obtain the unsprung mass velocity at the ith samplingWherein,for the sprung mass displacement obtained for the ith sample,for the sprung mass displacement obtained for the i-1 th sample,for the unsprung mass displacement obtained for the ith sample,unsprung mass displacement, z, obtained for sample i-1ⁱThe displacement of the road surface unevenness obtained by the ith sampling is obtained, and t is time;

step eight, the actuator controller 41 determines the suspension dynamic deflection (x) at the ith sampling according to the step seven₂-x₁)ⁱSpeed of sprung massDynamic displacement (x) of tyre₁-z)ⁱAnd unsprung mass velocityAccording to the formulaObtaining the state variable X at the ith sampling_i；

Step nine, the actuator controller 41 feeds back the gain matrix K according to the optimal control at the ith sampling determined in the step six_iAnd the state variable X at the ith sampling determined in the step eight_iAccording to the formulaCalculating to obtain the ideal optimal active control force U of the suspension actuator during the ith sampling_i。

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. The utility model provides a hydroelectricity integrated form self-powered initiative suspension actuator which characterized in that: comprises an actuator body and an actuator controller (41), wherein the actuator body comprises a piston cylinder (10), a piston (12), an upper piston rod (9), a lower piston rod (15), an upper lug ring (1) and a lower lug ring (20), the upper part of the piston cylinder (10) is connected with an upper end cover (3) of the piston cylinder, the lower part of the piston cylinder (10) is connected with a lower end cover (19) of the piston cylinder, the lower lug ring (20) is connected with the lower end cover (19) of the piston cylinder, the piston (12) is arranged at the middle upper part in the piston cylinder (10), the lower end of the upper piston rod (9) is connected with the piston (12), the upper end of the lower piston rod (15) is connected with the piston (12), the upper end of the upper piston rod (9) penetrates out of the upper end cover (3) of the piston cylinder to be connected with the upper lug ring (1), the upper part in the piston cylinder (10) is fixedly connected with an upper bushing (, an upper guide seat (7-1) which is sleeved on the upper piston rod (9) and used for guiding the up-and-down movement of the upper piston rod (9) is connected in the upper bushing (8-1) in a clamping manner through an upper clamping ring (6-1), an upper oil seal (4-1) sleeved on the upper piston rod (9) is arranged between the upper end cover (3) of the piston cylinder and the upper guide seat (7-1), and a first sealing ring (5-1) positioned between the upper end cover (3) of the piston cylinder and the upper bushing (8-1) is sleeved on the upper oil seal (4-1); the middle lower part in the piston cylinder (10) is fixedly connected with a lower bushing (8-2), the lower bushing (8-2) is connected with a lower guide seat (7-2) which is sleeved on a lower piston rod (15) in a clamping manner through a lower clamping ring (6-2) and used for guiding the up-and-down movement of the lower piston rod (15), a lower oil seal (4-2) sleeved on the lower piston rod (15) is arranged at the lower part of the lower guide seat (7-2), and a second sealing ring (5-2) positioned at the lower part of the lower bushing (8-2) is sleeved on the lower oil seal (4-2); a cavity in the piston cylinder (10) between the upper bushing (8-1), the upper guide seat (7-1) and the piston (12) is a piston cylinder upper cavity (11), a cavity in the piston cylinder (10) between the lower bushing (8-2), the lower guide seat (7-2) and the piston (12) is a piston cylinder lower cavity (14), and hydraulic oil (13) is arranged in the piston cylinder upper cavity (11) and the piston cylinder lower cavity (14); a check valve group, a hydraulic motor module and a brushless direct current motor (36) are embedded in the piston (12), the check valve group comprises a circulation valve (23), a compression valve (26), a compensation valve (27) and an extension valve (30), the hydraulic motor module comprises a hydraulic motor shell (31) and a shaft sleeve (33) fixedly connected to the inside of the hydraulic motor shell (31), a first bearing (32-1), a second bearing (32-2) and a third bearing (32-3) are arranged in the shaft sleeve (33), a first gear shaft (35) is supported and installed on the first bearing (32-1), a second gear shaft (38) is supported and installed on the second bearing (32-2), a third gear shaft (39) is supported and installed on the third bearing (32-3), and a first gear (24) is fixedly connected to the first gear shaft (35), a second gear (28) is fixedly connected to the second gear shaft (38), a third gear (29) is fixedly connected to the third gear shaft (39), the second gear (28) is respectively meshed with the first gear (24) and the third gear (29), and the second gear shaft (38) is fixedly connected with an output shaft of the brushless direct current motor (36); an upper oil outlet (45) and a lower oil inlet (46) which are positioned between the first gear (24) and the second gear (28), a lower oil outlet (47) and an upper oil inlet (48) which are positioned between the second gear (28) and the third gear (29) are arranged on the hydraulic motor shell (31), the circulation valve (23) is arranged on the upper oil outlet (45), the compression valve (26) is arranged on the lower oil inlet (46), the compensation valve (27) is arranged on the lower oil outlet (47), and the expansion valve (30) is arranged on the upper oil inlet (48); the cavity that is located in piston cylinder (10) between lower bush (8-2), lower guide holder (7-2) and piston cylinder lower end cover (19) is electric control chamber (49), be provided with control box (18) and super capacitor group (22) in electric control chamber (49), actuator controller (41) sets up in control box (18), still be provided with rectifier bridge (42), three-phase full-bridge inverter circuit (43), DC/DC converting circuit (44) and motor driver (17) in control box (18) to and first relay (50), second relay (51), third relay (52) and fourth relay (16), the input termination of actuator controller (41) has road surface irregularity displacement sensor (21-1) that is used for carrying out real-time detection to road surface irregularity displacement, is used for carrying out real-time detection's unsprung mass displacement sensor (21-2) to unsprung mass displacement, A sprung mass displacement sensor (21-3) for detecting the sprung mass displacement in real time, a piston rod speed sensor (21-4) for detecting the speed of the piston rod (15) in real time, and a hydraulic oil speed sensor (21-5) for detecting the flow rate of hydraulic oil (13) in real time, the first relay (50) is connected between the brushless DC motor (36) and the rectifier bridge (42), the second relay (51) is connected between the brushless direct current motor (36) and the three-phase full-bridge inverter circuit (43), the third relay (52) is connected between the rectifier bridge (42) and the DC/DC conversion circuit (44), the fourth relay (16) is connected between the three-phase full-bridge inverter circuit (43) and the DC/DC conversion circuit (44), the super capacitor bank (22) is connected with a DC/DC conversion circuit (44); the motor driver (17), the three-phase full-bridge inverter circuit (43), the first relay (50), the second relay (51), the third relay (52) and the fourth relay (16) are all connected with the output end of the actuator controller (41), and the brushless direct current motor (36) is connected with the output end of the motor driver (17).

2. The electro-hydraulic integrated self-powered active suspension actuator of claim 1, wherein: the upper end cover (3) of the piston cylinder is in threaded connection with the upper part of the piston cylinder (10), and the lower end cover (19) of the piston cylinder is in threaded connection with the lower part of the piston cylinder (10).

3. The electro-hydraulic integrated self-powered active suspension actuator of claim 1, wherein: the upper earrings (1) are fixedly connected with dust covers (2) covering the upper parts of the piston cylinders (10).

4. The electro-hydraulic integrated self-powered active suspension actuator of claim 1, wherein: the lower end of the upper piston rod (9) is welded with the piston (12), the upper end of the lower piston rod (15) is welded with the piston (12), and the upper end of the upper piston rod (9) penetrates out of the outer portion of the upper end cover (3) of the piston cylinder to be welded with the upper earring (1).

5. The electro-hydraulic integrated self-powered active suspension actuator of claim 1, wherein: and a third sealing ring (25) is arranged between the piston cylinder (10) and the piston (12).

6. The electro-hydraulic integrated self-powered active suspension actuator of claim 1, wherein: the first bearing (32-1), the second bearing (32-2) and the third bearing (32-3) are all ball bearings, and the number of the first bearings (32-1), the number of the second bearings (32-2) and the number of the third bearings (32-3) are all two.

7. The electro-hydraulic integrated self-powered active suspension actuator of claim 1, wherein: the first gear (24) is fixedly connected to a first gear shaft (35) through a first key (34-1), the second gear (28) is fixedly connected to a second gear shaft (38) through a second key (34-2), and the third gear (29) is fixedly connected to a third gear shaft (39) through a third key (34-3); the second gear shaft (38) is fixedly connected with an output shaft of the brushless direct current motor (36) through a coupler (37).

8. The electro-hydraulic integrated self-powered active suspension actuator of claim 1, wherein: the lower piston rod (15) is of a hollow structure, and a connecting wire when the brushless direct current motor (36) is connected with the output end of the motor driver (17) penetrates through the lower piston rod (15) of the hollow structure.

9. A method of controlling an electro-hydraulic integrated self-powered active suspension actuator as claimed in claim 1, the method comprising the steps of:

step I, a road surface irregularity displacement sensor (21-1) detects road surface irregularity displacement in real time, an unsprung mass displacement sensor (21-2) detects unsprung mass displacement in real time, a sprung mass displacement sensor (21-3) detects sprung mass displacement in real time, a piston rod speed sensor (21-4) detects the speed of a piston rod (15) in real time, a hydraulic oil speed sensor (21-5) detects the flow rate of hydraulic oil (13) in real time, and an actuator controller (41) periodically samples the road surface irregularity displacement, the unsprung mass displacement, the sprung mass displacement, the speed of a lower piston rod (15) and the flow rate of the hydraulic oil (13) respectively;

step II, firstly, the actuator controller (41) calls an LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator during the ith sampling_iThe actuator controller (41) then being responsive to the formula P_i＝U_i·V_iCalculating to obtain the instantaneous power value P of the suspension actuator at the ith sampling_iWherein V is_iThe speed of the lower piston rod (15) obtained by sampling for the ith time is the value of i which is a natural number different from 0; then, the actuators controlThe controller (41) judges the instantaneous power value P of the suspension actuator at the ith sampling_iPositive and negative of (b), when P is_iWhen the current is negative, the actuator controller (41) does not output a control signal to the brushless direct current motor (36), and the suspension actuator works in an energy feedback mode, wherein the specific working process is as follows: the vibration of a vehicle body drives an upper piston rod (9) to move, the upper piston rod (9) drives a piston (12) and a lower piston rod (15) to move, when the upper piston rod (9) moves upwards, the piston (12) moves upwards, a circulating valve (23) is closed under the action of hydraulic oil (13) in an upper cavity (11) of a piston cylinder, an expansion valve (30) is opened, the hydraulic oil (13) enters an upper oil inlet (48) through the expansion valve (30), a second gear (28) is pushed to rotate anticlockwise under the action of the hydraulic oil (13), a third gear (29) rotates clockwise, the hydraulic oil (13) pushes a compensation valve (27) to flow into a lower cavity (14) of the piston cylinder through a lower oil outlet (47), the second gear (28) rotates anticlockwise to drive a second gear shaft (38) to rotate, the second gear shaft (38) drives a brushless direct current motor (36) to rotate to generate electricity, at the moment, the actuator controller (41) outputs signals to control the first relay (50) and the third relay (52) to be electrified, the second relay (51) and the fourth relay (16) are not electrified, so that electric energy generated by the brushless direct current motor (36) is converted into unidirectional direct current through the rectifier bridge (42), and then is boosted through the DC/DC conversion circuit (44) to charge the super capacitor bank (22), and recovery of vibration energy is realized; when the upper piston rod (9) moves downwards, the piston (12) moves downwards, under the action of hydraulic oil (13) in a lower cavity (14) of the piston cylinder, the compensation valve (27) is closed, the compression valve (26) is opened, the hydraulic oil (13) enters a lower oil inlet (46) through the compression valve (26), under the action of the hydraulic oil (13), the second gear (28) is pushed to rotate anticlockwise, the first gear (24) rotates clockwise, the hydraulic oil (13) pushes the circulation valve (23) to flow into an upper cavity (11) of the piston cylinder through the upper oil outlet (45), the second gear (28) rotates anticlockwise to drive the second gear shaft (38) to rotate, the second gear shaft (38) rotates to drive the brushless direct current motor (36) to rotate to generate electricity, at the moment, the actuator controller (41) outputs signals to control the first relay (50) and the third relay (52) to be electrified, and the second relay (51) and the fourth relay (16) to be not electrified, the electric energy generated by the brushless DC motor (36) is converted into unidirectional DC through the rectifier bridge (42)The power is boosted by the DC/DC conversion circuit (44) and then is charged to the super capacitor bank (22), so that the recovery of vibration energy is realized;

when P is present_iFor the timing, firstly, the actuator controller (41) calls an LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator at the sampling time of the ith time_iThe actuator controller (41) further calculates a hydraulic pressure balance equation of the suspension actuator at the ith sampling timeDeducing the pressure difference of the oil inlet and the oil outlet of the hydraulic motor module when the ith sampling is obtainedWherein the ith sampling of the hydraulic total pressure loss of the suspension actuatorA is the cross-sectional area of the piston (12), ζ is the local drag coefficient, ρ is the density of the hydraulic oil (13), v_iThe flow rate of the hydraulic oil (13) at the ith sampling time; then, the actuator controller (41) first calculates the formulaCalculating an output torque of a second gear shaft (38) of the hydraulic motor moduleWherein q is the displacement of the hydraulic motor module, η_mFor the mechanical efficiency of the hydraulic motor module, the actuator control (41) is then based on the formulaCalculating a torque control signal to be output to the brushless DC motor (36) at the ith samplingThen, the actuator controller (41) controls the torque according to the torque control signalOutput PWM control signal control three-phase full-bridge inverter circuit (43) work to output signal, control second relay (51) and fourth relay (16) circular telegram, first relay (50) and third relay (52) do not circular telegram, super capacitor bank (22) discharge this moment, output voltage boosts the back through three-phase full-bridge inverter circuit (43) and supplies power for brushless DC motor (36) through DC/DC converting circuit (44), the work of liquid electricity integrated form self-energizing initiative suspension actuator is under the initiative mode, and specific working process is: when a downward active output force needs to be provided, the actuator controller (41) drives the brushless direct current motor (36) to rotate anticlockwise through the motor driver (17), the brushless direct current motor (36) drives the second gear shaft (38) to rotate anticlockwise, the second gear shaft (38) rotates anticlockwise to drive the second gear (28) to rotate anticlockwise, the second gear (28) rotates anticlockwise to drive the first gear (24) and the third gear (29) to rotate clockwise, hydraulic oil (13) flows into the upper piston cylinder cavity (11) from the lower piston cylinder cavity (14) through the compression valve (26) and the flow valve (23), the oil pressure of the upper piston cylinder cavity (11) rises to push the piston (12) to move downwards, and the piston (12) moves downwards to drive the upper piston rod (9) to move downwards, thereby providing downward active control force and transmitting the downward active control force to the vehicle body, and realizing the active control of the suspension actuator;

when the executor controller (41) drives the brushless direct current motor (36) to rotate clockwise through the motor driver (17), the brushless direct current motor (36) drives the second gear shaft (38) to rotate clockwise, the second gear shaft (38) rotates clockwise to drive the second gear (28) to rotate clockwise, the second gear (28) rotates clockwise to drive the first gear (24) and the third gear (29) to rotate counterclockwise, the flow of hydraulic oil (13) is blocked, thereby the damping coefficient is increased, the damping force is improved, and the semi-active control of the suspension actuator is realized.

10. The method of claim 9, wherein: in step IIThe actuator controller (41) calls the LQG optimal control module to analyze and process the sampled signal to obtain the ideal active control force U of the suspension actuator during the ith sampling_iThe specific process comprises the following steps:

step one, the actuator controller (41) is used for controlling the actuator according to the spring load mass m of the single wheel of the vehicle_sVehicle single-wheel unsprung mass m_uSuspension spring stiffness k_sTire stiffness k_tInherent damping coefficient c of vehicle suspension system_sIdeal active control force U of the suspension actuator at the ith sampling_iUnsprung mass displacement x₁And sprung mass displacement x₂(ii) a Taking the road surface unevenness displacement z as input excitation; using Newton's law of motion, establishingThe differential equation of the vehicle running vibration is as follows:

$\{\begin{array}{c}{m}_s{\stackrel{\·\·}{x}}_2+k_2\left(x_2-x_1\right)+c_s\left({\stackrel{\·}{x}}_2-{\stackrel{\·}{x}}_1\right)=U_i\\ m_u{\stackrel{\·\·}{x}}_1-k_2\left(x_2-x_1\right)-c_s\left({\stackrel{\·}{x}}_2-{\stackrel{\·}{x}}_1\right)+k_t\left(x_1-z\right)=-U_i\end{array};$

step two, the actuator controller (41) establishes a vehicle vibration state equation as follows:

$\left\{\begin{array}{c}\stackrel{\·}{X}=AX+{\mathrm{BU}}_i+G\stackrel{\·}{z}\\ Y=CX+{\mathrm{DU}}_i\end{array}\right.;$

thirdly, the actuator controller (41) selects the vibration speed of the vehicle bodyWheel vibration speedDynamic deflection (x) of suspension₂-x₁) Dynamic deformation of tire (x)₁-z) is a state variable, resulting inThe specific forms of the system matrix A, the control matrix B and the disturbance input matrix G are obtained as follows:

$A=\left[\begin{array}{cccc}0& 1& 0& -1\\ -\frac{k_s}{m_s}& -\frac{c_s}{m_s}& 0& \frac{c_s}{m_s}\\ 0& 0& 0& 1\\ \frac{k_s}{m_u}& \frac{c_s}{m_u}& -\frac{k_t}{m_u}& -\frac{c_s}{m_u}\end{array}\right],B=\left[\begin{array}{c}0\\ \frac{1}{m_s}\\ 0\\ -\frac{1}{m_u}\end{array}\right],G=\left[\begin{array}{c}0\\ 0\\ -1\\ 0\end{array}\right]$

fourthly, the actuator controller (41) selects the vertical acceleration of the vehicle bodyDynamic deflection (x) of suspension₂-x₁) Dynamic deformation of tire (x)₁-z) as an output variable, obtainingThe output matrix C and the transfer matrix D are then of the form:

$C=\left[\begin{array}{cccc}-\frac{k_s}{m_s}& -\frac{c_s}{m_s}& 0& \frac{c_s}{m_s}\\ 1& 0& 0& 0\\ 0& 0& 1& 0\end{array}\right],D=\left[\begin{array}{c}\frac{1}{m_s}\\ 0\\ 0\end{array}\right]$

step five, the actuatorThe controller (41) converts the output equation Y into CX + DU_iSubstituting into formulaIn the method, the obtained quadratic performance indexes are as follows:and has:Q＝C^TqC，N＝C^TqD，R＝r+D^TqD; wherein t is time, q₁As a vehicle body acceleration weighting factor, q₂Weighting factor q for dynamic deflection of suspension₃The dynamic deformation weighting coefficient of the tire, and r is an energy consumption weighting coefficient; q is a semi-positive definite symmetric weighting matrix of the state variable, N is a weighting matrix of the relevance of the two variables, and R is a positive definite symmetric weighting matrix of the control variable;

step six, the actuator controller (41) uses the LQR function provided in Matlab software to obtain the optimal control feedback gain matrix K at the ith sampling time according to the system matrix A and the control matrix B determined in the step three and the weighting matrix Q, the weighting matrix N and the weighting matrix R determined in the step five_i；

Seventhly, the actuator controller (41) is used for controlling the actuator according to a formulaCalculating to obtain the suspension dynamic deflection (x) during the ith sampling₂-x₁)ⁱAccording to the formulaCalculating to obtain the sprung mass velocity at the ith samplingAccording to the formulaCalculating to obtain the tire dynamic displacement (x) at the ith sampling₁-z)ⁱAccording to the formulaCalculating to obtain the unsprung mass velocity at the ith samplingWherein,for the sprung mass displacement obtained for the ith sample,for the sprung mass displacement obtained for the i-1 th sample,for the unsprung mass displacement obtained for the ith sample,unsprung mass displacement, z, obtained for sample i-1ⁱThe displacement of the road surface unevenness obtained by the ith sampling is obtained, and t is time;

step eight, the actuator controller (41) determines the suspension dynamic deflection (x) at the ith sampling according to the step seven₂-x¹)ⁱSpeed of sprung massDynamic displacement (x) of tyre₁-z)ⁱAnd unsprung mass velocityAccording to the formulaGet the ith sampleState variable X of time_i；

Step nine, the actuator controller (41) controls the feedback gain matrix Ki according to the optimal control at the ith sampling determined in the step six and the state variable X at the ith sampling determined in the step eight_iAccording to the formulaCalculating to obtain the ideal optimal active control force U of the suspension actuator during the ith sampling_i。