Vehicle damping control system and method based on magneto-rheological oil gas spring

Abstract

The application discloses a vehicle damping control system and method based on a magneto-rheological oil gas spring, which comprises a magneto-rheological oil gas suspension unit, a collection unit and a control unit. The magneto-rheological oil gas suspension unit comprises a magneto-rheological oil gas spring and a PINCH mode magneto-rheological valve. The magneto-rheological oil gas spring is used for hydraulic interconnection in the oil gas suspension, and the PINCH mode magneto-rheological valve is used for switching the form of the hydraulic interconnection. The collection unit is used for collecting the motion posture information of the vehicle. The control unit is used for adjusting the interconnection form of the oil gas suspension according to the motion posture information of the vehicle, and controlling the motion posture of the vehicle, so that the running state of the vehicle reaches a target state. The application can obtain better roll stiffness and pitch stiffness, and improves the overall damping performance and steering stability of the heavy load vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magneto-rheological vibration reduction, in particular to a vehicle vibration reduction control system and method based on magneto-rheological oil gas spring. BACKGROUND

[0002] At present, for the hardware aspect of vehicle vibration reduction control, heavy-duty vehicles mostly use suspension devices such as steel plate spring, coil spring and torsion bar spring, but in the actual use process, there are disadvantages such as unadjustable stiffness and damping, poor stiffness, large space occupation, poor damping effect, and it is difficult to ensure that the vehicle has high maneuverability and off-road performance. The magneto-rheological technology has the advantages of fast response, low energy consumption and large adjustable range, and at present, a small number of people have introduced the magneto-rheological technology into the oil gas spring and proposed the concept of magneto-rheological oil gas spring, but it has not been applied to hydraulic interconnection and controlled.

[0003] In addition, for the algorithm aspect of vehicle vibration reduction control, the traditional skyhook control algorithm is relatively simple, which can better suppress the vertical vibration of the vehicle body, but it is difficult to ensure the steering stability; the optimal control, robust control and other algorithms require more state variables and have high requirements for hardware devices, so their application is limited; the fuzzy control, neural network control and other algorithms are relatively complex, the control rules depend on expert experience, and they have not been well applied. CN100484788C proposes a human-like intelligent control method, which has the characteristics of simple algorithm logic and uses fewer sensors, but it is only a control method for magneto-rheological semi-active suspension and does not consider the hydraulic interconnection between the suspensions. When sudden turns or sudden brakes occur, it is difficult to ensure the stability of the vehicle body due to the limited output damping force of the device, while the suspension system with hydraulic interconnection has superior nonlinear elastic characteristics, good damping performance and carrying capacity, which can maximize the stability of the vehicle. According to the connection mode of the hydraulic cylinder, the hydraulic interconnection can be divided into same direction and reverse interconnection, and the switching of the two states is usually realized by using an electromagnetic reversing valve. The electromagnetic reversing valve itself has a simple structure and a low price, but its valve core can only be in two extreme positions and cannot be continuously adjusted, and it has high requirements for the cleanliness of the medium, and cannot be used with particulate and viscous medium. Therefore, a vehicle vibration reduction control system and method based on magneto-rheological oil gas spring is needed to solve the above problems. SUMMARY

[0004] Therefore, the purpose of the present application is to overcome the defects in the prior art and provide a vehicle vibration reduction control system and method based on magneto-rheological oil gas spring, which can obtain better roll stiffness and pitch stiffness, and improve the overall damping performance and steering stability of heavy-duty vehicles.

[0005] The vehicle damping control system based on the magneto-rheological oil gas spring of the application comprises a magneto-rheological oil gas suspension unit, a collection unit and a control unit;

[0006] The magneto-rheological oil gas suspension unit comprises a magneto-rheological oil gas spring and a PINCH mode magneto-rheological valve; the magneto-rheological oil gas spring is used for hydraulic interconnection in the oil gas suspension, and the PINCH mode magneto-rheological valve is used for switching the form of the hydraulic interconnection;

[0007] The collection unit is used for collecting the motion posture information of the vehicle;

[0008] The control unit is used for adjusting the interconnection form of the oil gas suspension according to the motion posture information of the vehicle, and controlling the motion posture of the vehicle, so that the running state of the vehicle reaches a target state.

[0009] Further, the magneto-rheological oil gas spring comprises a left front oil gas spring, a left rear oil gas spring, a right front oil gas spring and a right rear oil gas spring;

[0010] The oil port p1 of the left front oil gas spring is connected with the oil port p3 and the oil port p4 of the right front oil gas spring respectively; a PINCH mode magneto-rheological valve 2a is arranged on the connecting pipeline of the oil port p1 and the oil port p3; and a PINCH mode magneto-rheological valve 2c is arranged on the connecting pipeline of the oil port p1 and the oil port p4;

[0011] The oil port p2 of the left front oil gas spring is connected with the oil port p3 and the oil port p4 of the right front oil gas spring respectively; a PINCH mode magneto-rheological valve 2b is arranged on the connecting pipeline of the oil port p2 and the oil port p3; and a PINCH mode magneto-rheological valve 2d is arranged on the connecting pipeline of the oil port p2 and the oil port p4;

[0012] The oil port p5 of the left rear oil gas spring is connected with the oil port p7 and the oil port p8 of the right rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2e is arranged on the connecting pipeline of the oil port p5 and the oil port p7; and a PINCH mode magneto-rheological valve 2g is arranged on the connecting pipeline of the oil port p5 and the oil port p8;

[0013] The oil port p6 of the left rear oil gas spring is connected with the oil port p7 and the oil port p8 of the right rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2f is arranged on the connecting pipeline of the oil port p6 and the oil port p7; and a PINCH mode magneto-rheological valve 2h is arranged on the connecting pipeline of the oil port p6 and the oil port p8;

[0014] The oil port p1 of the left front oil gas spring is also connected with the oil port p5 and the oil port p6 of the left rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2i is arranged on the connecting pipeline of the oil port p1 and the oil port p6; and a PINCH mode magneto-rheological valve 2j is arranged on the connecting pipeline of the oil port p1 and the oil port p5;

[0015] The oil port p2 of the left front oil gas spring is also connected with the oil port p7 and the oil port p8 of the right rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2k is arranged on the connecting pipeline between the oil port p2 and the oil port p7; and a PINCH mode magneto-rheological valve 2l is arranged on the connecting pipeline between the oil port p2 and the oil port p8.

[0016] Further, the collection unit includes an acceleration sensor and an inclination sensor, both of which are arranged at the vehicle body mass center.

[0017] Further, the interconnection form of the oil gas suspension includes anti-roll interconnection, anti-pitch interconnection, anti-vertical interconnection and hydraulic locking.

[0018] A vehicle damping control method based on a magneto-rheological oil gas spring, comprising:

[0019] The hydraulic interconnection of the oil gas suspension is performed by using the magneto-rheological oil gas spring, and the switching of the hydraulic interconnection form is performed by using the PINCH mode magneto-rheological valve;

[0020] Collecting the motion posture information of the vehicle;

[0021] According to the motion posture information of the vehicle, the interconnection form of the oil gas suspension is adjusted, and the motion posture of the vehicle is controlled, so that the running state of the vehicle reaches the target state.

[0022] Further, the magneto-rheological oil gas spring includes a left front oil gas spring, a left rear oil gas spring, a right front oil gas spring and a right rear oil gas spring;

[0023] The oil port p1 of the left front oil gas spring is connected with the oil port p3 and the oil port p4 of the right front oil gas spring respectively; a PINCH mode magneto-rheological valve 2a is arranged on the connecting pipeline between the oil port p1 and the oil port p3; and a PINCH mode magneto-rheological valve 2c is arranged on the connecting pipeline between the oil port p1 and the oil port p4.

[0024] The oil port p2 of the left front oil gas spring is connected with the oil port p3 and the oil port p4 of the right front oil gas spring respectively; a PINCH mode magneto-rheological valve 2b is arranged on the connecting pipeline between the oil port p2 and the oil port p3; and a PINCH mode magneto-rheological valve 2d is arranged on the connecting pipeline between the oil port p2 and the oil port p4.

[0025] The oil port p5 of the left rear oil gas spring is connected with the oil port p7 and the oil port p8 of the right rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2e is arranged on the connecting pipeline between the oil port p5 and the oil port p7; and a PINCH mode magneto-rheological valve 2g is arranged on the connecting pipeline between the oil port p5 and the oil port p8.

[0026] The oil port p6 of the left rear oil-air spring is connected with the oil port p7 and the oil port p8 of the right rear oil-air spring respectively; a PINCH mode magneto-rheological valve 2f is arranged on the connecting pipeline between the oil port p6 and the oil port p7; a PINCH mode magneto-rheological valve 2h is arranged on the connecting pipeline between the oil port p6 and the oil port p8;

[0027] The oil port p1 of the left front oil-air spring is further connected with the oil port p5 and the oil port p6 of the left rear oil-air spring respectively; a PINCH mode magneto-rheological valve 2i is arranged on the connecting pipeline between the oil port p1 and the oil port p6; a PINCH mode magneto-rheological valve 2j is arranged on the connecting pipeline between the oil port p1 and the oil port p5;

[0028] The oil port p2 of the left front oil-air spring is further connected with the oil port p7 and the oil port p8 of the right rear oil-air spring respectively; a PINCH mode magneto-rheological valve 2k is arranged on the connecting pipeline between the oil port p2 and the oil port p7; a PINCH mode magneto-rheological valve 2l is arranged on the connecting pipeline between the oil port p2 and the oil port p8.

[0029] Further, the motion posture information includes a vertical acceleration of the vehicle body, a pitch angle and a roll angle.

[0030] Further, according to the motion posture information of the vehicle, the interconnection form of the oil-air suspension is adjusted, and specifically includes:

[0031] When the vehicle body posture is any one of a first single posture, a first double posture, a second double posture and a three-posture, the interconnection form of the oil-air suspension adopts an anti-roll interconnection;

[0032] When the vehicle body posture is any one of a second single posture and a third double posture, the interconnection form of the oil-air suspension adopts an anti-pitch interconnection;

[0033] When the vehicle body posture is a third single posture, the interconnection form of the oil-air suspension adopts an anti-vertical interconnection;

[0034] When the vehicle body posture is in an ideal motion posture, the interconnection form of the oil-air suspension adopts hydraulic locking;

[0035] The first single posture includes roll, the second single posture includes pitch, the third single posture includes vertical, the first double posture includes roll and pitch, the second double posture includes roll and vertical, the third double posture includes pitch and vertical, and the three-posture includes roll, pitch and vertical.

[0036] Further, the vehicle motion posture is controlled so that the vehicle operating state reaches a target state, including the following steps:

[0037] a. judging whether the vehicle body posture is in an ideal motion posture, if yes, maintaining the current posture and hydraulic locking, if not, entering step b;

[0038] b. Determine whether the vehicle body posture deviates from the ideal motion posture, if yes, go to step c, if no, go to step d;

[0039] c. Proportional and differential control is performed on the vehicle body posture to make the vehicle body motion posture reach the ideal motion posture, specifically including:

[0040] A first decoupling equation of the vehicle body motion posture is constructed:

[0041]

[0042] Wherein, a represents the distance from the vehicle body mass center to the front axle, b represents the distance from the vehicle body mass center to the rear axle, and w represents the vehicle body width; F dfl , F dfr , F drl , and F drr respectively represent the output damping force of the left front, right front, left rear, and right rear magneto-rheological oil gas spring; K p-z , , and K p-θ are the proportional coefficients when controlling the vertical, pitch, and roll motion respectively; z(n) , and θ(n) are the vertical displacement, pitch angle, and roll angle of the vehicle body at time n respectively; K d-z , , and K d-θ are the differential coefficients when controlling the vertical, pitch, and roll motion respectively; , and are the vertical velocity, pitch angular velocity, and roll angular velocity of the vehicle body at a certain time n respectively;

[0043] The first decoupling equation of the vehicle body motion posture is solved to calculate the required magneto-rheological oil gas spring output damping force F df1 ;

[0044] According to the required output damping force F df1 , the required input current I c1 of the magneto-rheological oil gas spring is calculated reversely, and the input current to the magneto-rheological oil gas spring is adjusted to the required input current I c1 ;

[0045] d. Skyhook damping control is performed on the vehicle body posture to make the vehicle body motion posture reach the ideal motion posture, specifically including:

[0046] A second decoupling equation of the vehicle body motion posture is constructed:

[0047]

[0048] Wherein, a represents the distance from the vehicle body mass center to the front axle, b represents the distance from the vehicle body mass center to the rear axle, and w represents the vehicle body width; Fdfl , F dfr , F drl and F drr respectively represent the output damping force of the left front, right front, left rear and right rear magneto-rheological hydro-pneumatic spring; C sky-z , and C sky-θ are the skyhook damping coefficients when controlling the vertical, pitch and roll motion respectively; and are the vertical velocity, pitch angular velocity and roll angular velocity of the vehicle body at time n respectively;

[0049] The second decoupling equation of the vehicle body motion posture is solved to calculate the required output damping force F df2 of the magneto-rheological hydro-pneumatic spring;

[0050] According to the required output damping force F df2 , the required input current I c2 of the magneto-rheological hydro-pneumatic spring is calculated reversely, and the input current of the magneto-rheological hydro-pneumatic spring is adjusted to the required input current I c2 .

[0051] The beneficial effects of the present application are: the vehicle damping control system and method based on the magneto-rheological hydro-pneumatic spring disclosed by the present application adopts the magneto-rheological hydro-pneumatic spring to replace the traditional hydro-pneumatic spring for hydraulic interconnection, and adopts the PINCH mode magneto-rheological valve to replace the electromagnetic reversing valve and the throttle valve for switching of the hydraulic interconnection mode, so that better roll stiffness and pitch stiffness can be obtained; based on the human-like intelligent control diagram theory and in combination with the characteristics of the magneto-rheological hydro-pneumatic spring hydraulic interconnection, a magneto-rheological hydro-pneumatic suspension coordinated decoupling human-like intelligent controller with a characteristic model and a multi-modal control structure is designed, the algorithm logic is simple, fewer sensors are used, and the controller can be conveniently applied to a heavy-duty vehicle equipped with an interconnected magneto-rheological hydro-pneumatic suspension, real-time control is realized, and the smoothness and handling stability of the heavy-duty vehicle are further ensured. BRIEF DESCRIPTION OF DRAWINGS

[0052] The present application will be further described below in combination with the drawings and embodiments:

[0053] Figure 1 It is a structure diagram of the magneto-rheological hydro-pneumatic spring of the present application;

[0054] Figure 2 It is a hydraulic interconnection structure schematic diagram of the magneto-rheological hydro-pneumatic spring of the present application;

[0055] Figure 3 It is a working principle diagram of the PINCH mode magneto-rheological valve of the present application;

[0056] Figure 4 It is a division schematic diagram of the interconnected form of the hydro-pneumatic suspension of the present application;

[0057] Figure 5 Fig. 1 is a schematic diagram of the vehicle damping control principle based on the magneto-rheological oil-gas spring of the present application;

[0058] Wherein, 4-piston rod, 5-floating piston, 6-end cover, 7-coil, 8-piston, 9-outer cylinder, p9-charging port. DETAILED DESCRIPTION

[0059] The present application is further described below in conjunction with the accompanying drawings of the specification, as shown in the drawings:

[0060] The vehicle damping control system based on the magneto-rheological oil-gas spring of the present application comprises a magneto-rheological oil-gas suspension unit, a collection unit and a control unit.

[0061] The magneto-rheological oil-gas suspension unit comprises a magneto-rheological oil-gas spring and a PINCH mode magneto-rheological valve; the magneto-rheological oil-gas spring is used for hydraulic interconnection in the oil-gas suspension, and the PINCH mode magneto-rheological valve is used for switching the form of hydraulic interconnection.

[0062] The collection unit is used for collecting the motion posture information of the vehicle; wherein, the motion posture information comprises the vertical acceleration of the vehicle body, the pitch angle and the roll angle.

[0063] The control unit is used for adjusting the interconnection form of the oil-gas suspension according to the motion posture information of the vehicle, and controlling the motion posture of the vehicle, so that the running state of the vehicle reaches the target state; wherein, the control unit comprises a controller, which can adopt the existing single-chip microcomputer, and will not be described here.

[0064] Through the above system, the magneto-rheological oil-gas spring is used to replace the traditional oil-gas spring for hydraulic interconnection, and the PINCH mode magneto-rheological valve is used to replace the electromagnetic reversing valve and the throttle valve for switching the form of hydraulic interconnection; so that better roll stiffness and pitch stiffness can be obtained, the natural frequency of the vehicle is reduced, and the stability of the vehicle driving is improved. Wherein, the PINCH mode magneto-rheological valve adopts the existing magnetic gradient Pinch mode of the magneto-rheological fluid, and the magneto-rheological oil-gas spring can be additionally provided with an oil port based on the existing magneto-rheological oil-gas spring, so that the magneto-rheological oil-gas spring has two oil ports.

[0065] As Figure 1As shown, during operation, a certain amount of high-pressure nitrogen gas is introduced into chamber S4 through the air inlet p9 to provide nonlinear elastic force support. When the magnetorheological oil spring piston 8 moves to the right, the oil spring is in its compression stroke, and the magnetorheological fluid in chamber S1 is compressed into chambers S3 and S2. The magnetorheological fluid in chamber S3 pushes the floating piston 5 to the left, compressing the gas in chamber S4 and thus changing the output stiffness of the oil spring. The magnetorheological fluid in chamber S1 flows into the annular chamber S2 through the working gap between piston 8 and outer cylinder 9. The magnetic field at the working gap is mainly provided by coil 7. Changing the magnitude of the current applied to coil 7 can change the strength of the magnetic field at the working gap, thereby changing the damping characteristics of the magnetorheological oil spring.

[0066] like Figure 3 As shown, for the PINCH mode magnetorheological valve, as the coil current gradually increases, the actual effective diameter De of the PINCH mode magnetorheological valve orifice gradually decreases. This leads to a gradual increase in the pressure drop across the PINCH mode magnetorheological valve, which acts as a throttling valve. When the current increases to a certain extent, the ferromagnetic particles in the magnetorheological fluid will accumulate at the PINCH mode magnetorheological valve orifice, forming a completely blocked structure, which blocks the oil circuit.

[0067] In this embodiment, as Figure 2 As shown, the magnetorheological hydro-pneumatic springs are of several types, including a left front hydro-pneumatic spring 1a, a left rear hydro-pneumatic spring 1b, a right front hydro-pneumatic spring 1c, and a right rear hydro-pneumatic spring 1d.

[0068] The oil port p1 of the left front gas spring is connected to the oil ports p3 and p4 of the right front gas spring respectively; a PINCH mode magnetorheological valve 2a is installed on the connecting pipe between oil ports p1 and p3; a PINCH mode magnetorheological valve 2c is installed on the connecting pipe between oil ports p1 and p4.

[0069] The oil port p2 of the left front gas spring is connected to the oil ports p3 and p4 of the right front gas spring respectively; a PINCH mode magnetorheological valve 2b is installed on the connecting pipe between oil ports p2 and p3; a PINCH mode magnetorheological valve 2d is installed on the connecting pipe between oil ports p2 and p4.

[0070] The oil port p5 of the left rear gas spring is connected to the oil ports p7 and p8 of the right rear gas spring respectively; a PINCH mode magnetorheological valve 2e is installed on the connecting pipe between oil port p5 and oil port p7; a PINCH mode magnetorheological valve 2g is installed on the connecting pipe between oil port p5 and oil port p8.

[0071] The oil port p6 of the left rear oil gas spring is connected with the oil port p7 and the oil port p8 of the right rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2f is arranged on the connecting pipeline of the oil port p6 and the oil port p7; a PINCH mode magneto-rheological valve 2h is arranged on the connecting pipeline of the oil port p6 and the oil port p8;

[0072] The oil port p1 of the left front oil gas spring is also connected with the oil port p5 and the oil port p6 of the left rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2i is arranged on the connecting pipeline of the oil port p1 and the oil port p6; a PINCH mode magneto-rheological valve 2j is arranged on the connecting pipeline of the oil port p1 and the oil port p5;

[0073] The oil port p2 of the left front oil gas spring is also connected with the oil port p7 and the oil port p8 of the right rear oil gas spring respectively; a PINCH mode magneto-rheological valve 2k is arranged on the connecting pipeline of the oil port p2 and the oil port p7; a PINCH mode magneto-rheological valve 2l is arranged on the connecting pipeline of the oil port p2 and the oil port p8.

[0074] By changing the on-off state of the PINCH mode magneto-rheological valve, four interconnection forms of the magnetic-rheological oil gas spring of anti-roll type, anti-pitch type, anti-vertical type and hydraulic locking type can be formed. When the PINCH mode magneto-rheological valves 2b, 2c, 2f, 2g, 2j and 2k are turned on, and the PINCH mode magneto-rheological valves 2a, 2d, 2e, 2h, 2i and 2l are blocked, the oil ports p1, p4, p5 and p8 of the magnetic-rheological oil gas spring are connected to form an oil circuit, and the oil ports p2, p3, p6 and p7 form another oil circuit, at this time, it is in the anti-roll type interconnection mode;

[0075] When the PINCH mode magneto-rheological valves 2a, 2d, 2e, 2h, 2i and 2k are turned on, and the PINCH mode magneto-rheological valves 2b, 2c, 2f, 2g, 2j and 2l are blocked, the oil ports p1, p3, p6 and p8 are connected, and p2, p4, p5 and p7 are connected, which is in the anti-pitch type interconnection mode;

[0076] When the PINCH mode magneto-rheological valves 2a, 2d, 2e, 2h, 2j and 2l are turned on, and the PINCH mode magneto-rheological valves 2b, 2c, 2f, 2g, 2i and 2k are blocked, the oil ports p1, p3, p5 and p7 are connected, and p2, p4, p6 and p8 are connected, which is in the anti-vertical type interconnection mode;

[0077] When all the PINCH mode magneto-rheological valves are powered off, that is, all the PINCH mode magneto-rheological valves are turned on, the magnetic-rheological oil gas spring is in a hydraulic locking state.

[0078] By using the magneto-rheological oil gas spring to replace the traditional oil gas spring, the damping parameters of the oil gas suspension system can be regulated by changing the size of the magnetic field, further improving the damping performance of the heavy-duty vehicle. In addition, compared with the traditional hydraulic circuit, the use of accumulators can be omitted, making the overall structure more compact. The classification of hydraulic interconnection can be divided into same direction and reverse interconnection according to the connection mode of the hydraulic cylinder. The switching of the two states is usually realized by using electromagnetic reversing valve. The electromagnetic reversing valve itself has simple structure, but its spool can only be in two extreme positions and cannot be continuously adjusted. At the same time, it has high requirements for the cleanliness of the medium, and cannot be used for medium containing particles and viscous medium. By using PINCH mode magneto-rheological valve to replace electromagnetic reversing valve and throttle valve, the effective diameter of the valve cross section is changed by changing the size of the applied current, and then the on-off of the circuit is controlled, which can realize the transformation of the interconnection form and the continuous adjustment of the damping in the circuit.

[0079] In the embodiment, the acquisition unit includes an acceleration sensor and an inclination sensor, both of which are arranged at the mass center of the vehicle body. The acceleration sensor is used to acquire the vertical acceleration of the vehicle body, and the vertical velocity and the vertical displacement can be calculated inversely from the vertical acceleration; the inclination sensor is used to acquire the pitch angle and the roll angle of the vehicle body. The posture of the vehicle body during driving mainly includes roll, pitch, vertical, and combinations of two or three of the three motion postures, plus a target posture (ideal motion posture), as shown in Figure 4 , there are a total of 8 vehicle body postures.

[0080] In the embodiment, the interconnection form of the oil gas suspension includes roll type interconnection, pitch type interconnection, vertical type interconnection, and hydraulic locking.

[0081] As shown in Figure 4 , according to the intuitive influence degree of the motion form on driving safety, the interconnection form of the heavy-duty vehicle suspension is determined in the order of roll, pitch, and vertical, that is:

[0082] When the vehicle body posture is roll, roll-pitch mixed, roll-vertical mixed, and roll-pitch-vertical mixed, the interconnection form of the magneto-rheological oil gas suspension adopts anti-roll interconnection;

[0083] When the vehicle body posture is pitch and pitch-vertical mixed, the interconnection form adopts anti-pitch interconnection;

[0084] When the vehicle body posture is vertical motion, the interconnection form adopts anti-vertical interconnection;

[0085] When the vehicle body posture is in the ideal motion state, the interconnection form adopts hydraulic locking.

[0086] This invention also relates to a vehicle vibration damping control method based on a magnetorheological hydro-gas spring. The control method utilizes the vehicle vibration damping control system based on a magnetorheological hydro-gas spring described in the above embodiments, and includes:

[0087] Magnetorheological hydro-pneumatic springs are used for hydraulic interconnection of the hydro-pneumatic suspension, and PINCH mode magnetorheological valves are used to switch the hydraulic interconnection mode.

[0088] Collect vehicle motion attitude information;

[0089] Based on the vehicle's motion posture information, the interconnection mode of the oil and gas suspension is adjusted, and the vehicle's motion posture is controlled so that the vehicle's operating state reaches the target state.

[0090] By using the above control method, the interconnection mode of the hydropneumatic suspension is adjusted according to the vehicle's motion attitude information, so that the hydropneumatic suspension is in the set interconnection state. On the one hand, this can make the vehicle have better anti-roll stiffness and anti-pitch stiffness. On the other hand, it can make the vehicle's operating state reach the target state more quickly during the process of controlling the vehicle's motion attitude.

[0091] In this embodiment, as Figure 4 As shown, the interconnection method of the hydropneumatic suspension is adjusted according to the vehicle's motion attitude information, specifically including:

[0092] When the vehicle body posture is any of the first single posture, the first dual posture, the second dual posture, or the three postures, the interconnection form of the oil-gas suspension adopts an anti-roll type interconnection.

[0093] When the vehicle body posture is either the second single posture or the third dual posture, the interconnection form of the oil-gas suspension adopts an anti-pitch interconnection.

[0094] When the vehicle body posture is the third single posture, the interconnection form of the oil-air suspension adopts the anti-vertical interconnection;

[0095] When the vehicle body is in an ideal motion posture, the interconnection of the air suspension adopts hydraulic locking;

[0096] The first single posture includes tilt; the second single posture includes pitch; the third single posture includes vertical; the first dual posture includes tilt and pitch; the second dual posture includes tilt and vertical; the third dual posture includes pitch and vertical; and the three postures include tilt, pitch, and vertical.

[0097] In this embodiment, as Figure 5 As shown, controlling the vehicle's motion attitude to achieve the target vehicle operating state includes the following steps:

[0098] a. judging whether the vehicle body posture is in the ideal motion posture, if yes, maintaining the current posture and hydraulic locking; if no, entering step b;

[0099] b. judging whether the vehicle body posture deviates from the ideal motion posture, if yes, entering step c, if no, entering step d; wherein, if deviating, it indicates that it is moving away from the ideal motion posture, if not deviating, it indicates that it is moving towards the ideal motion posture although it is not in the ideal motion posture;

[0100] c. performing proportional and differential control on the vehicle body posture so that the vehicle body motion posture reaches the ideal motion posture, specifically including:

[0101] Taking the example that all the three postures deviate from the ideal motion posture, a first decoupling equation of the vehicle body motion posture is constructed:

[0102]

[0103] Wherein, a represents the distance from the vehicle body mass center to the front axle, b represents the distance from the vehicle body mass center to the rear axle, and w represents the vehicle body width; F dfl , F dfr , F drl , and F drr respectively represent the output damping forces of the left front, right front, left rear, and right rear magneto-rheological oil gas springs; K p-z , , and K p-θ respectively are the proportional coefficients when controlling the vertical, pitch, and roll motions; z(n) , and θ(n) respectively are the vertical displacement, pitch angle, and roll angle of the vehicle body at time n; K d-z , , and K d-θ respectively are the differential coefficients when controlling the vertical, pitch, and roll motions; , and respectively are the vertical velocity, pitch angular velocity, and roll angular velocity of the vehicle body at time n;

[0104] The first decoupling equation of the vehicle body motion posture is solved to calculate the required output damping force F df1 of the magneto-rheological oil gas spring;

[0105] According to the required output damping force F df1 , the required input current I c1 of the magneto-rheological oil gas spring is calculated reversely, and the input current to the magneto-rheological oil gas spring is adjusted to the required input current I c1 ;

[0106] d. performing skyhook damping control on the vehicle body posture so that the vehicle body motion posture reaches the ideal motion posture, specifically including:

[0107] Taking the three postures all tend to the ideal motion posture as an example, the second decoupling equation of the vehicle body motion posture is constructed:

[0108]

[0109] Wherein, a represents the distance from the vehicle body mass center to the front axle, b represents the distance from the vehicle body mass center to the rear axle, w represents the vehicle body width; F dfl , F dfr , F drl and F drr respectively represent the output damping force of the left front, right front, left rear and right rear magneto-rheological oil gas spring; C sky-z , and C sky-θ are the skyhook damping coefficients when controlling the vertical, pitch and roll motion respectively; and are the vertical velocity, pitch angular velocity and roll angular velocity of the vehicle body at time n respectively;

[0110] The second decoupling equation of the vehicle body motion posture is solved, and the required magneto-rheological oil gas spring output damping force F df2 is calculated;

[0111] According to the required output damping force F df2 , the required input current I c2 of the magneto-rheological oil gas spring is calculated reversely, and the input current to the magneto-rheological oil gas spring is adjusted to the required input current I c2 .

[0112] Similarly, if the vehicle body motion posture deviates partially, part of which tends to the ideal motion posture, the part of the trend adopts skyhook damping control, and the deviated part adopts proportional differential control, which will not be described here.

[0113] Specifically, for the complex and variable motion posture of the vehicle body, a human-simulated intelligent controller with hierarchical and multi-controller modalities is designed for posture coordination control. The skyhook damping control, proportional differential control and current switching control are selected as the basis of the control modal base element of the human-simulated intelligent control, and different control modes are formed by adjusting the skyhook damping coefficient, the proportional differential coefficient and the on-off of the PINCH mode magneto-rheological valve current.

[0114] The control force equation is obtained by controlling the vertical motion, pitch and roll vibration of the vehicle body respectively, and the required magneto-rheological oil gas spring control damping force is calculated by decoupling, so as to realize the control of each motion posture of the heavy vehicle in motion, and achieve the suppression of posture change and the realization of steering stability and smoothness.

[0115] The design of the human-simulated intelligent controller is based on the dynamic intelligent schema, mainly including a perception schema set SP , motion pattern set S M and associated pattern set S A The design of the kinesthetic intelligent pattern is similar for each motion posture. The design process of the kinesthetic intelligent pattern is described by taking the two motion postures as examples due to the particularity of the coupling of the ideal motion state and the three states of the vehicle body. The design of other motion postures can be referenced.

[0116] 1. When the vehicle body is in the ideal motion posture, the control target is to maintain the motion posture and perform hydraulic locking. The pattern structure in this stage is as follows:

[0117] (1) Perception pattern

[0118] The structure of the perception pattern is as follows:

[0119]

[0120] wherein the input variable R1 is the suspension system state signal, Q1 is the characteristic base element set, which is mainly selected according to how to effectively extract the vehicle body posture, K1 is the relationship matrix, is the operator, and Φ1 is the perception characteristic mode. The selection of Q1 is as follows:

[0121]

[0122] Since the vertical, pitch and roll motions of the vehicle body are small when the vehicle body is in the ideal motion posture, the relationship matrix K1 can be selected as [1 1 1], and the perception characteristic mode Φ1 can be expressed as:

[0123]

[0124] (2) Motion pattern

[0125] The structure of the motion pattern is as follows:

[0126] S M1 =(R1, P1, L1, Ψ1, U1)

[0127] wherein P1 is the control mode base element set, L1 is the mode selection matrix, and Ψ1 is the control mode set. The design of the motion pattern can be understood as the design of the control mode. Since the vehicle body is in the ideal motion posture, the next action should be to maintain the current motion posture and perform hydraulic locking. Therefore, the control mode base element set can be expressed as:

[0128] P1=[p 11 | F dfl (n) = F dfl (n-1), F dfr (n) = F dfr(n-1),

[0129] F drl (n)=F drl (n-1),F drr (n)=F drr (n-1),p 12 |A1~A 12 =0000,0000,0000] T

[0130] In the formula, A1~A 12 =0000,0000,0000 represents A1 to A 12 The current flowing through the device is 0A.

[0131] Given the modality selection matrix L1 = [1 1], the control mode set can be represented as:

[0132] Ψ1=L1·P1={ψ 11 |p 11 ,p 12}

[0133] (3) Relationship diagram

[0134] Based on the state variables of the vehicle body collected by the current sensors, the vehicle's motion attitude is determined, and then the corresponding control mode is used for control. The structure of the correlation diagram can be represented as follows:

[0135] S A,1 ={Ω1:Φ1→Ψ1},Ω1={ω 11}

[0136] ω 11 :IFφ 11 THENψ 11

[0137] 2. Similarly, when the vehicle body is in a coupled state of roll, pitch, and verticality, the diagram structure for this stage is as follows:

[0138] (1) Perceptual schema

[0139]

[0140] The characteristic element Q8 can be represented as:

[0141]

[0142] When combining feature primitives, it is necessary to consider whether the current motion state deviates from or approaches the ideal state. The relation matrix K8 can be represented as:

[0143]

[0144] Then the perceived feature modality Φ8can be expressed as:

[0145]

[0146] (2) Motion pattern

[0147] S M8 = (R8, P8, L8, Ψ8, U8)

[0148] Since the current motion posture is the coupling of the three motion states, decoupling calculation is needed to obtain the output damping force of the four MR oil gas springs. For the body state deviating from the ideal motion posture, the MR oil gas spring adopts proportional differential control, and for the body state tending to the ideal motion posture, it adopts skyhook damping control, as follows:

[0149] When the roll, pitch and vertical states all tend to the ideal posture, i.e. the perceived feature modality is φ 81 , the three motion states all adopt skyhook damping control, and the body torsion equation is supplemented:

[0150] Then the decoupling matrix can be expressed as:

[0151]

[0152] Similarly, when the roll, pitch and vertical states all deviate from the ideal posture, i.e. the perceived feature modality is φ 88 , the three motion states all adopt proportional differential control, and the corresponding decoupling matrix can be expressed as:

[0153]

[0154] The decoupling matrix of other feature modes is similar and will not be repeated here. By solving the above equation, the required control damping force vectors p 81 to p 88 corresponding to the feature modes φ 81 to φ 88 can be obtained.

[0155] At this time, the interconnection form of the oil gas suspension adopts anti-roll interconnection, so the primitive set of the motion pattern is:

[0156] P8= [p 81 , p 82 , p 83 , p 84 , p 85 , p 86 , p 87 , p 88 , p 89 |A1~A 12= 1001, 1001, 1001] T

[0157] The modal selection matrix is: L8 = [I T],

[0158] wherein, I is an 8-order unit matrix, T = [1 1 1 1 1 1 1 1] T The control modal set can be expressed as:

[0159] Ψ8 = L8·P8 = {ψ 81 ,...,ψ 8j}

[0160] wherein, j = 1,...,8; ψ 8j = {p 8j ,p 89}.

[0161] (3) Associated diagram

[0162] Ω8: Φ8→Ψ8, Ω8 = {ω 81 ,ω 82 ,…,ω 88}

[0163] ω 81 : IF φ 8j THEN ψ 8j (j = 1,...,8)

[0164] wherein, n-1 represents the last time of time n; δ z , and δ θ are threshold parameters for determining the posture; A1-A 12 represent the current size of valves 2a-2l, respectively, for the convenience of description, 0 represents no electricity, and 1 represents the current size (determined according to the experiment) that can make the PINCH mode magnetorheological valve play a blocking role.

[0165] The motion diagram of other vehicle postures can be designed by referring to the three motion state coupled postures, and the control force of the non-existing motion form can be set to 0 to supplement the determination, and after obtaining the required control damping force, the control input current can be inversely solved according to the inverse model of the magnetorheological oil gas spring, and then the real-time control of the magnetorheological oil gas spring is carried out.

[0166] The application adopts four magnetorheological oil gas springs in front, back, left and right to replace traditional oil gas springs, and uses 12 PINCH mode magnetorheological valves for hydraulic interconnection state switching and pressure regulation in a hydraulic circuit, in addition, selects skyhook control and proportional differential control as control primitives of human-like intelligent control, uses acceleration sensors and inclination sensors to obtain state signals of a vehicle body in real time, and then judges the vehicle body posture, adopts different control modes for adjustment for each different vehicle body posture, changes the form of hydraulic interconnection and the output damping force of the magnetorheological oil gas spring, so as to suppress the vertical, pitching and rolling movement of the vehicle body, and make the vehicle body keep a stable movement state, the control precision is high, the algorithm logic is simple, and the required state variables are less.

[0167] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A vehicle vibration damping control system based on a magnetorheological hydro-air spring, characterized in that: Includes a magnetorheological hydro-pneumatic suspension unit, a data acquisition unit, and a control unit; The magnetorheological hydropneumatic suspension unit includes a magnetorheological hydropneumatic spring and a PINCH mode magnetorheological valve; the magnetorheological hydropneumatic spring is used for hydraulic interconnection in the hydropneumatic suspension, and the PINCH mode magnetorheological valve is used to switch the hydraulic interconnection mode. The acquisition unit is used to acquire the vehicle's motion attitude information; The control unit is used to adjust the interconnection mode of the air suspension according to the vehicle's motion posture information, and to control the vehicle's motion posture so that the vehicle's operating state reaches the target state. The magnetorheological hydro-pneumatic spring includes a left front hydro-pneumatic spring, a left rear hydro-pneumatic spring, a right front hydro-pneumatic spring, and a right rear hydro-pneumatic spring. The oil port p1 of the left front gas spring is connected to the oil ports p3 and p4 of the right front gas spring respectively; a PINCH mode magnetorheological valve 2a is installed on the connecting pipe between oil ports p1 and p3; a PINCH mode magnetorheological valve 2c is installed on the connecting pipe between oil ports p1 and p4. The oil port p2 of the left front gas spring is connected to the oil ports p3 and p4 of the right front gas spring respectively; a PINCH mode magnetorheological valve 2b is installed on the connecting pipe between oil ports p2 and p3; a PINCH mode magnetorheological valve 2d is installed on the connecting pipe between oil ports p2 and p4. The oil port p5 of the left rear gas spring is connected to the oil ports p7 and p8 of the right rear gas spring respectively; a PINCH mode magnetorheological valve 2e is installed on the connecting pipe between oil port p5 and oil port p7; a PINCH mode magnetorheological valve 2g is installed on the connecting pipe between oil port p5 and oil port p8. The oil port p6 of the left rear gas spring is connected to the oil ports p7 and p8 of the right rear gas spring respectively; a PINCH mode magnetorheological valve 2f is installed on the connecting pipe between oil ports p6 and p7; a PINCH mode magnetorheological valve 2h is installed on the connecting pipe between oil ports p6 and p8. The oil port p1 of the left front gas spring is also connected to the oil ports p5 and p6 of the left rear gas spring respectively; a PINCH mode magnetorheological valve 2i is installed on the connecting pipe between oil port p1 and oil port p6; a PINCH mode magnetorheological valve 2j is installed on the connecting pipe between oil port p1 and oil port p5. The oil port p2 of the left front gas spring is also connected to the oil ports p7 and p8 of the right rear gas spring respectively; a PINCH mode magnetorheological valve 2k is installed on the connecting pipe between oil port p2 and oil port p7; a PINCH mode magnetorheological valve 2l is installed on the connecting pipe between oil port p2 and oil port p8. By changing the on / off state of the PINCH mode magnetorheological valve, four interconnected forms of magnetorheological oil-gas springs are formed: anti-tilt, anti-pitch, anti-vertical, and hydraulic lock-in.

2. The vehicle vibration damping control system based on magnetorheological hydro-air springs according to claim 1, characterized in that: The acquisition unit includes an acceleration sensor and a tilt sensor, both located at the center of gravity of the vehicle body.

3. A vehicle vibration reduction control method based on magnetorheological hydro-air springs, characterized in that: include: Magnetorheological hydro-pneumatic springs are used for hydraulic interconnection of the hydro-pneumatic suspension, and PINCH mode magnetorheological valves are used to switch the hydraulic interconnection mode. Collect vehicle motion attitude information; Based on the vehicle's motion posture information, the interconnection mode of the oil and gas suspension is adjusted, and the vehicle's motion posture is controlled so that the vehicle's operating state reaches the target state. The magnetorheological hydro-pneumatic spring includes a left front hydro-pneumatic spring, a left rear hydro-pneumatic spring, a right front hydro-pneumatic spring, and a right rear hydro-pneumatic spring. The oil port p1 of the left front gas spring is connected to the oil ports p3 and p4 of the right front gas spring respectively; a PINCH mode magnetorheological valve 2a is installed on the connecting pipe between oil ports p1 and p3; a PINCH mode magnetorheological valve 2c is installed on the connecting pipe between oil ports p1 and p4. The oil port p2 of the left front gas spring is connected to the oil ports p3 and p4 of the right front gas spring respectively; a PINCH mode magnetorheological valve 2b is installed on the connecting pipe between oil ports p2 and p3; a PINCH mode magnetorheological valve 2d is installed on the connecting pipe between oil ports p2 and p4. The oil port p5 of the left rear gas spring is connected to the oil ports p7 and p8 of the right rear gas spring respectively; a PINCH mode magnetorheological valve 2e is installed on the connecting pipe between oil port p5 and oil port p7; a PINCH mode magnetorheological valve 2g is installed on the connecting pipe between oil port p5 and oil port p8. The oil port p6 of the left rear gas spring is connected to the oil ports p7 and p8 of the right rear gas spring respectively; a PINCH mode magnetorheological valve 2f is installed on the connecting pipe between oil ports p6 and p7; a PINCH mode magnetorheological valve 2h is installed on the connecting pipe between oil ports p6 and p8. The oil port p1 of the left front gas spring is also connected to the oil ports p5 and p6 of the left rear gas spring respectively; a PINCH mode magnetorheological valve 2i is installed on the connecting pipe between oil port p1 and oil port p6; a PINCH mode magnetorheological valve 2j is installed on the connecting pipe between oil port p1 and oil port p5. The oil port p2 of the left front gas spring is also connected to the oil ports p7 and p8 of the right rear gas spring respectively; a PINCH mode magnetorheological valve 2k is installed on the connecting pipe between oil port p2 and oil port p7; a PINCH mode magnetorheological valve 2l is installed on the connecting pipe between oil port p2 and oil port p8. By changing the on / off state of the PINCH mode magnetorheological valve, four interconnected forms of magnetorheological oil-gas springs are formed: anti-tilt, anti-pitch, anti-vertical, and hydraulic lock-in.

4. The vehicle vibration reduction control method based on magnetorheological hydro-air springs according to claim 3, characterized in that: The motion attitude information includes the vehicle's vertical acceleration, pitch angle, and roll angle.

5. The vehicle vibration reduction control method based on magnetorheological hydro-air springs according to claim 3, characterized in that: Based on the vehicle's motion posture information, the interconnection method of the hydraulic suspension is adjusted, specifically including: When the vehicle body posture is any of the first single posture, the first dual posture, the second dual posture, or the three postures, the interconnection form of the oil-gas suspension adopts an anti-roll type interconnection. When the vehicle body posture is either the second single posture or the third dual posture, the interconnection form of the oil-gas suspension adopts an anti-pitch interconnection. When the vehicle body posture is the third single posture, the interconnection form of the oil-air suspension adopts the anti-vertical interconnection; When the vehicle body is in an ideal motion posture, the interconnection of the air suspension adopts hydraulic locking; The first single posture includes tilt; the second single posture includes pitch; the third single posture includes vertical; the first dual posture includes tilt and pitch; the second dual posture includes tilt and vertical; the third dual posture includes pitch and vertical; and the three postures include tilt, pitch, and vertical.

6. The vehicle vibration reduction control method based on magnetorheological hydro-air springs according to claim 3, characterized in that: Controlling the vehicle's motion attitude to achieve a target operating state includes the following steps: a. Determine if the vehicle body is in an ideal motion posture. If so, maintain the current posture and hydraulically lock it; otherwise, proceed to step b. b. Determine whether the vehicle body posture deviates from the ideal motion posture. If yes, proceed to step c; otherwise, proceed to step d. c. Perform proportional-derivative control on the vehicle body attitude to achieve the ideal vehicle body motion attitude, specifically including: Construct the first decoupling equation for the vehicle's motion attitude; Solve the first decoupling equation for the vehicle's motion attitude to calculate the required output damping force of the magnetorheological hydro-pneumatic spring. ; Based on the required output damping force The required input current for the magnetorheological hydro-spring can be calculated by reverse calculation. Adjust the current input to the magnetorheological hydro-spring to the required input current. ; d. Implement roof damping control to achieve the ideal vehicle body posture, specifically including: Construct the second decoupling equation for the vehicle's motion attitude; Solve the second decoupling equation for the vehicle's motion attitude to calculate the required output damping force of the magnetorheological hydro-pneumatic spring. ; Based on the required output damping force The required input current for the magnetorheological hydro-spring can be calculated by reverse calculation. Adjust the current input to the magnetorheological hydro-spring to the required input current. .

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