Split-acting oil-gas active suspension and control method

Abstract

The application provides a split-acting oil-gas active suspension and a control method. The suspension comprises a suspension controller, a hydraulic actuator, a motor actuator electrically connected with the suspension controller, and a sensor for collecting motion state information of the suspension system, the motor actuator is connected with the hydraulic actuator through a hydraulic oil pipeline; the suspension controller outputs a control signal to control the motor actuator according to a certain control algorithm based on the sensor output signal, the motor actuator drives the hydraulic actuator to act through hydraulic transmission, thereby realizing active control of the suspension system. The application retains the hydraulic actuator of the traditional passive oil-gas suspension, can reduce the cost and difficulty of the active modification of the passive oil-gas suspension. In the driving condition of good road condition, the suspension system is passively controlled by the hydraulic actuator by stopping the control of the servo motor, so as to reduce the power consumption and achieve the purpose of energy saving.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automobile control, and particularly relates to a split-acting oil-gas active suspension and a control method. BACKGROUND

[0002] With the rapid development of vehicle electrification and intelligentization, people's demand for vehicle ride comfort and handling stability is also constantly improving. For special vehicles and engineering vehicles that exceed the design vehicle limit in appearance and weight and have special purposes, in addition to considering the perception of the human body on the vehicle to the vibration, the higher requirements of special purposes on the vehicle driving performance also need to be considered, and the design of the vehicle suspension system is an important link to improve this key performance. Generally, the suspension system can be divided into passive suspension, semi-active suspension and active suspension according to whether the damping and stiffness of the vehicle suspension system can be adjusted. The common passive suspension is composed of spring and damper elements, and the parameters cannot be adjusted according to the change of working conditions, and the adaptability to variable working conditions is poor; the semi-active suspension is usually composed of a spring with adjustable stiffness or a damper with adjustable damping, and the system generally adjusts the spring stiffness coefficient and damper damping coefficient according to the feedback signals such as the acceleration response of the sprung mass during work, so that the characteristics of the vehicle suspension system can change in real time. The active suspension uses an active controllable device as a suspension actuator, calculates and sends the required suspension actuator control signal according to the input of the vehicle motion posture and the active control strategy, actively adjusts and generates the suspension control force, and always keeps the performance of the suspension system in the best state. Therefore, compared with the traditional passive suspension and semi-active suspension, it has better adaptive characteristics and relatively greater advantages in performance. The common types of active suspension currently mainly include air active suspension, electromagnetic rheological active suspension and oil-gas active suspension.

[0003] For special vehicles and engineering vehicles, oil-gas suspension and leaf spring suspension are widely used. Compared with leaf spring suspension, oil-gas suspension can dynamically adjust the stiffness and adjust the vehicle height to improve the road passability, and to a certain extent, it can better meet the performance requirements of the vehicle under complex road conditions. However, the stiffness variation characteristics of the passive oil-gas suspension depend on the invariable inflation pressure in the accumulator, so the stiffness adjustment range is limited, which limits the further improvement of the vehicle driving performance, and therefore the combination of active suspension technology and oil-gas suspension technology has great application prospect. The existing active oil-gas suspension system generally connects a hydraulic oil source to the accumulator based on the passive oil-gas suspension, and controls the proportional valve on the oil source pipeline through the controller to continuously adjust the stiffness characteristics of the suspension system and achieve active control. Although the system has the advantages of large unit energy storage ratio, compact structure and rigid locking, the hydraulic structure also has the disadvantages of slow response, low energy storage efficiency, complex structure and difficult maintenance. SUMMARY

[0004] In order to solve the above problems in the prior art, the present application provides a split-acting oil-gas active suspension and a control method.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions.

[0006] In a first aspect, the present application provides a split-acting oil-gas active suspension, comprising: a suspension controller, a hydraulic actuator, a motor actuator electrically connected with the suspension controller, and a sensor for collecting motion state information of the suspension system, wherein the motor actuator is connected with the hydraulic actuator through a hydraulic oil pipeline; the suspension controller outputs a control signal to control the motor actuator according to a certain control algorithm based on the output signal of the sensor, and the motor actuator drives the hydraulic actuator to act through hydraulic transmission, thereby realizing active control of the suspension system.

[0007] Further, the motor actuator mainly comprises: a servo motor electrically connected with the suspension controller, and a piston connected with the hydraulic actuator through the hydraulic oil pipeline, wherein the output shaft of the servo motor is connected with the piston through a reducer and a transmission mechanism.

[0008] Further, the suspension further comprises a damping valve system installed on the hydraulic oil pipeline connecting the motor actuator and the hydraulic actuator.

[0009] Further, the suspension further comprises a hydraulic oil source connected with the hydraulic oil cavity of the motor actuator through a pipeline, and an electromagnetic valve installed on the outlet pipeline of the hydraulic oil source, wherein the control end of the electromagnetic valve is electrically connected with the suspension controller.

[0010] Further, when the active suspension system works in normal conditions, the electromagnetic valve is in an off state, and the hydraulic oil source does not participate in the system work; when the hydraulic oil in the cylinder of the motor actuator is lost or the initial adjustment of the body height and the system stiffness is needed, the electromagnetic valve is in an on state, and the hydraulic oil source supplements the oil amount of the motor actuator.

[0011] Further, the signals output by the sensor include: displacement, velocity and acceleration signals of the spring mass and the non-spring mass of the suspension system.

[0012] Further, in a driving condition with good road conditions, the motor actuator is controlled to stop working, and the passive control of the suspension system is realized by the hydraulic actuator.

[0013] In a second aspect, the present application provides a method for controlling the suspension, comprising the following steps:

[0014] The suspension controller collects the motion state data of the suspension system output by the sensor in real time;

[0015] The suspension controller outputs a control signal to the motor actuator according to a certain control algorithm based on the state data;

[0016] The motor actuator drives the hydraulic actuator to act under the action of the control signal, thereby achieving active control of the suspension system.

[0017] Further, the signals output by the sensors include displacement, speed and acceleration signals of the sprung mass and the unsprung mass of the suspension system.

[0018] Further, in a driving condition with good road conditions, the motor actuator is controlled to stop working, and the hydraulic actuator is used to achieve passive control of the suspension system.

[0019] Compared with the prior art, the present application has the following beneficial effects.

[0020] The split actuation type oil-gas active suspension provided by the present application comprises a suspension controller, a hydraulic actuator, a motor actuator electrically connected to the suspension controller and sensors for collecting motion state information of the suspension system, and the motor actuator is connected to the hydraulic actuator through a hydraulic oil pipeline; the suspension controller outputs a control signal to the motor actuator according to a certain control algorithm based on the signals output by the sensors, and the motor actuator drives the hydraulic actuator to act through hydraulic transmission, thereby achieving active control of the suspension system. The control signal output by the suspension controller directly acts on the motor actuator, which can better improve the response efficiency of the actuator. The present application retains the hydraulic actuator of the traditional passive oil-gas suspension, which can reduce the cost and difficulty of active modification of the passive oil-gas suspension. In a driving condition with good road conditions, the motor actuator is controlled to stop working, and the hydraulic actuator is used to passively control the suspension system, which can reduce power consumption and achieve the purpose of energy saving. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A block diagram of a split actuation type oil-gas active suspension according to an embodiment of the present application.

[0022] Figure 2 A structural schematic diagram of the motor actuator.

[0023] Figure 3 A structural schematic diagram of a split actuation type oil-gas active suspension system.

[0024] Figure 4 A flowchart of a method for controlling the suspension according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present application clearer and more understandable, the present application is further described below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0026] Figure 1 A block diagram of a split-acting oil-gas active suspension according to an embodiment of the present application comprises: a suspension controller 1, a hydraulic actuator 3, a motor actuator 2 electrically connected with the suspension controller 1, and a sensor 4 for collecting motion state information of the suspension system, the motor actuator 2 being connected with the hydraulic actuator 3 through a hydraulic oil pipeline; the suspension controller 1 outputs a control signal to the motor actuator 2 according to a certain control algorithm based on the output signal of the sensor 4, and the motor actuator 2 drives the hydraulic actuator 3 to act through hydraulic transmission, thereby realizing active control of the suspension system.

[0027] In the embodiment, the suspension mainly comprises the suspension controller 1, the hydraulic actuator 3, the motor actuator 2 and the sensor 4. The suspension controller 1 is electrically connected with the motor actuator 2 and the sensor 4 respectively; the motor actuator 2 is connected with the hydraulic actuator 3 through a hydraulic oil pipeline. The hydraulic actuator 3 and the motor actuator 2 together constitute a split-acting actuator in the embodiment, and the motor actuator 2 replaces the accumulator structure in the traditional passive oil-gas suspension system and has an active control function. The sensor 4 is used to output motion state data of the suspension system in real time, such as displacement, acceleration and speed, and output the data to the suspension controller 1. The suspension controller 1 is the control and data processing center of the suspension, and is used to complete data processing tasks and coordinate the work of the entire device through output control signals. The suspension controller 1 mainly processes the real-time acquired motion state data, outputs control signals to the motor actuator 2 according to a certain control algorithm, and controls the movement of the servo motor of the motor actuator 2; the motor actuator 2 provides driving force for the hydraulic actuator 3 through hydraulic transmission, so that the hydraulic actuator 3 acts, thereby realizing control of the suspension system, i.e. minimizing the movement of the vehicle body in the vertical direction. In the embodiment, the control signal output by the suspension controller 1 directly acts on the motor actuator 2, which can better improve the response efficiency of the actuator.

[0028] As an optional embodiment, the motor actuator 2 mainly comprises: a servo motor electrically connected with the suspension controller 1, and a piston connected with the hydraulic actuator 3 through a hydraulic oil pipeline, the output shaft of the servo motor being connected with the piston through a reducer and a transmission mechanism.

[0029] The embodiment gives a structure of the motor actuator 2. The motor actuator 2 mainly consists of a servo motor and a piston. The operation of the servo motor is controlled by the suspension controller 1, and the driving force is transmitted to the piston through the reducer and the transmission mechanism. The cylinder body of the piston is connected to the hydraulic actuator 3 (cylinder body of the piston) through the hydraulic oil pipeline, and the movement of the piston is transmitted to the hydraulic actuator 3.

[0030] Figure 2 is a specific structure diagram of the motor actuator 2. The motor actuator 2 includes in turn: a servo motor 201, a motor output shaft 202, a transmission shaft 203, a tapered roller bearing (205, 207, 211, 214), a reducer gear set (206, 213), a cylinder side wall (204, 210, 212, 216, 222, 223), a cylinder bottom cover (209, 224), a cylinder top cover 208, a ball screw shaft 215, a ball nut connecting rod 217, a high-pressure sealed roller bearing 218, a shaft coupling 219, a ball head connecting rod 220 and a piston 221. Among them, the transmission shaft 203 and the ball screw shaft 215 are connected with the reducer gear 206 and the reducer gear 213 through the key. The cylinder structure mainly plays a limiting and fixing role for the actuator main parts, and the piston 221 is fixed by the upper and lower parts through the ball head connecting rod 220. The design of this structure mainly considers the coaxial error in the process of mechanical processing and manufacturing, and the connection mode of the ball head connecting rod is easier to implement in engineering. The high-pressure sealed bearing 218 seals the inert gas between the upper end surface of the piston 221 and the lower end surface of the bearing, forming a gas chamber cavity. The space between the cylinder bottom cover 224 and the lower end surface of the piston 221 is a hydraulic oil cavity, which is connected to the oil cavity of the hydraulic actuator 3 through the oil pipeline interface on the left side of the bottom cover. The gas chamber cavity above the piston 221 together constitutes an oil-air spring. The servo motor output shaft 202 transmits torque to the ball screw shaft 215 through the transmission shaft 203 and the reducer gear set, and the ball screw shaft 215 and the ball nut connecting rod 217 together constitute a ball screw mechanical transmission structure, which converts the rotary motion of the motor output shaft into the vertical translation motion of the ball nut connecting rod 217. The ball nut connecting rod 217 is connected to the ball head connecting rod 220 through the shaft coupling 219, thereby realizing the vertical movement of the piston 221. The hydraulic oil in the hydraulic actuator 3 is filled and discharged to the hydraulic oil in the motor actuator 2, thereby actively controlling and adjusting the volume of the gas chamber in the oil-air spring, achieving the purpose of changing the stiffness of the suspension system oil-air spring.

[0031] As an optional embodiment, the suspension further comprises a damping valve system installed on the hydraulic oil pipeline connecting the motor actuator 2 and the hydraulic actuator 3.

[0032] The damping valve system is an important part of the suspension system. In the embodiment, a damping valve system is arranged on the hydraulic oil pipeline connecting the motor actuator 2 and the hydraulic actuator 3, and the position is as shown in Figure 3 . Figure 3 In the embodiment, the cylinder body 106, the piston 103, the ball screw transmission shaft 104, the speed reducer 105 and the servo motor 108 belong to the motor actuator 2. The connecting rod piston 112 and the cylinder body 113 belong to the hydraulic chamber actuator. The upper end surface of the piston 103 of the motor actuator 2 is filled with nitrogen in the cavity between the sealing bearing. The lower end surface of the piston 103 is filled with hydraulic oil in the cavity between the bottom cover of the cylinder body 106. The left pipeline of the cavity is connected with the cavity filled with hydraulic oil between the upper end surface of the connecting rod piston 112 of the hydraulic actuator 3 and the top cover of the cylinder body 113 through the damping valve system 111.

[0033] As an optional embodiment, the suspension further comprises a hydraulic oil source connected with the hydraulic oil cavity of the motor actuator 2 through a pipeline, and an electromagnetic valve installed on the outlet pipeline of the hydraulic oil source, and the control end of the electromagnetic valve is electrically connected with the suspension controller 1.

[0034] The embodiment provides a technical scheme for supplementing the hydraulic oil of the motor actuator 2. The hydraulic oil source is arranged to supplement the hydraulic oil of the motor actuator 2. In order to control conveniently, the electromagnetic valve installed on the outlet pipeline of the hydraulic oil source is further arranged, and the suspension controller 1 realizes the start and stop of the oil supplement of the motor actuator 2 by controlling the on-off of the electromagnetic valve. As shown in Figure 3 , the hydraulic oil cavity of the motor actuator 2 is connected with the hydraulic oil source 101 through the electromagnetic valve 102 through the right side pipeline interface of the bottom cover of the cylinder body 106. Figure 3 The ECU 107 in the embodiment is the suspension controller 1.

[0035] As an optional embodiment, when the suspension works in the normal working condition, the electromagnetic valve is in the off state, and the hydraulic oil source does not participate in the system work; when the hydraulic oil in the cylinder of the motor actuator 2 is lost or the initial adjustment of the vehicle body height and the system stiffness is needed, the electromagnetic valve is in the on state, and the hydraulic oil source supplements the oil amount of the motor actuator 2.

[0036] The embodiment provides a control method for supplementing the oil amount of the motor actuator 2. The oil amount of the motor actuator 2 is supplemented only when the hydraulic oil in the cylinder is lost or the initial adjustment of the vehicle body height and the system stiffness is needed; and when the active suspension system works in the normal working condition, the oil supplement cannot be performed, so as to avoid affecting the normal work of the motor actuator 2. Therefore, in the normal working condition, the suspension controller 1 makes the electromagnetic valve in the off state by outputting the control signal; and the electromagnetic valve is in the on state only when the oil amount needs to be supplemented.

[0037] As an optional embodiment, the signals output by the sensor 4 include the displacement, speed and acceleration signals of the spring mass and the non-spring mass of the suspension system.

[0038] The embodiment gives the output signal type of the sensor 4. The control of the suspension system is mainly for the sprung mass and the unsprung mass, so it is necessary for the sensor 4 to output its motion state signals, such as displacement, velocity and acceleration signals. As shown in the figure, the sensor 109 and the sensor 117 are respectively installed on the sprung object 110 and the unsprung object 114. The excitation 116 from the road is transmitted to the suspension system through the tire and finally to the vehicle body and acts on the sprung object 110 and the unsprung object 114, and the sensor 109 and the sensor 117 input the collected displacement, velocity and acceleration signals of the sprung object 110 and the unsprung object 114 to the ECU 107 (i.e. the suspension controller 1). Figure 3

[0039] As an optional embodiment, in the driving condition of good road condition, the motor type actuator 2 is controlled to stop working, and the hydraulic type actuator 3 is used to realize the passive control of the suspension system.

[0040] The embodiment gives a technical scheme for the passive control of the suspension system. In the case of good road condition, the vibration of the vehicle body is small, and the motor type actuator 2 generally does not need to be actively acted. Therefore, in order to reduce the energy consumption and save the energy, when the vehicle is driven on the road with good road condition, the suspension controller 1 outputs the control signal to make the motor type actuator 2 stop working (the servo motor is powered off); the hydraulic oil between the hydraulic type actuator 3 and the motor type actuator 2 is transmitted along the connecting pipeline under the action of the road excitation, and since there is no active control action, the motor type actuator 2 is equivalent to the accumulator of the traditional passive oil gas suspension at this time. That is to say, in the driving condition of good road condition, the motor type actuator 2 stops working, and the hydraulic type actuator 3 is used to realize the passive control of the suspension system. Therefore, the control device proposed in the embodiment has two working modes: one is the active control mode, and the motor type actuator 2 and the hydraulic type actuator 3 cooperate to realize the control of the suspension system; and the other is the passive control mode, and the hydraulic type actuator 3 is used to control the suspension system alone.

[0041] Figure 4 For an embodiment of the application, a flow chart of a method for controlling the suspension is provided, and the method comprises the following steps:

[0042] In step 101, the suspension controller 1 collects the motion state data of the suspension system output by the sensor 4 in real time;

[0043] In step 102, the suspension controller 1 outputs the control signal to the motor type actuator 2 according to a certain control algorithm based on the state data;

[0044] ​In step 103, the motor actuator 2 is driven by the hydraulic transmission to drive the hydraulic actuator 3 to act under the control of the control signal, thereby to realize the active control of the suspension system.

[0045] The method of the embodiment is similar to the technical solution of the device embodiment in principle and technical effects, and thus will not be described here again. The same applies to the following embodiments, which will not be described again. Figure 1 The method of the embodiment is similar to the technical solution of the device embodiment in principle and technical effects, and thus will not be described here again. The same applies to the following embodiments, which will not be described again.

[0046] As an optional embodiment, the signals output by the sensor 4 include the displacement, speed and acceleration signals of the sprung mass and the unsprung mass of the suspension system.

[0047] As an optional embodiment, in the driving condition of good road condition, the motor actuator 2 is controlled to stop working, and the passive control of the suspension system is realized by the hydraulic actuator 3.

[0048] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A split-type hydropneumatic active suspension, characterized in that, include: The system includes a suspension controller, a hydraulic actuator, a motor-driven actuator electrically connected to the suspension controller, and a sensor for collecting motion state information of the suspension system. The motor-driven actuator is connected to the hydraulic actuator via a hydraulic oil pipeline. Based on the sensor output signal, the suspension controller outputs a control signal according to a certain control algorithm to control the motor-driven actuator. The motor-driven actuator drives the hydraulic actuator to move through hydraulic transmission, thereby realizing active control of the suspension system. The motor-driven actuator includes: a servo motor electrically connected to the suspension controller, and a piston connected to the hydraulic actuator via a hydraulic oil pipeline. The output shaft of the servo motor is connected to the piston via a reducer and a transmission mechanism. Specifically, it includes: a servo motor, a motor output shaft, a transmission shaft, a tapered roller bearing, a reducer gear set, a cylinder sidewall, a cylinder bottom cover, a cylinder top cover, a ball screw shaft, a ball nut connecting rod, a high-pressure sealed roller bearing, a coupling, a ball joint connecting rod, and a piston. The transmission shaft and ball screw shaft are connected to the reducer gears via keys. The piston consists of upper and lower parts fixed to the ball joint connecting rod by screws. The high-pressure sealed bearing is used to seal inert gas between the upper end face of the piston and the lower end face of the bearing, forming a gas chamber. The space between the cylinder bottom cover and the lower end face of the piston is... The hydraulic oil chamber is connected to the hydraulic actuator's oil chamber via an oil pipe interface on the left side of the bottom cover. The piston and the air chamber above it together form a gas spring. The servo motor output shaft transmits torque to the ball screw shaft via a transmission shaft and a reduction gear set. The ball screw shaft and the ball nut connecting rod together form a ball screw mechanical transmission structure, converting the rotational motion of the motor output shaft into the vertical translational motion of the ball nut connecting rod. The ball nut connecting rod is connected to the ball joint connecting rod via a coupling to realize the vertical movement of the piston. The hydraulic oil in the hydraulic actuator fills and releases the hydraulic oil in the hydraulic chamber of the motor actuator as the piston moves vertically, realizing the active control and adjustment of the air chamber volume in the gas spring, thereby changing the stiffness of the gas spring in the suspension system. The control of the suspension system includes two control methods: one is the active control method, which operates under normal road conditions and is controlled by a combination of electric motor actuators and hydraulic actuators; the other is the passive control method, which operates under better road conditions and is controlled by a hydraulic actuator alone.

2. The split-action hydropneumatic active suspension according to claim 1, characterized in that, The suspension also includes a damping valve system installed on the hydraulic oil lines connecting the motor-driven actuator and the hydraulic actuator.

3. The split-action hydropneumatic active suspension according to claim 1, characterized in that, The suspension also includes a hydraulic oil source connected to the hydraulic oil chamber of the motor actuator via a pipeline, and a solenoid valve installed on the outlet pipeline of the hydraulic oil source. The control end of the solenoid valve is electrically connected to the suspension controller.

4. The split-action hydropneumatic active suspension according to claim 3, characterized in that, When the suspension system is operating under normal conditions, the solenoid valve is in the open state, and the hydraulic oil source does not participate in the system operation; when the hydraulic oil in the motor actuator cylinder is lost or when the vehicle height and system stiffness are initially adjusted, the solenoid valve is in the open state, and the hydraulic oil source replenishes the oil for the motor actuator.

5. The split-action hydropneumatic active suspension according to claim 1, characterized in that, The signals output by the sensor include: displacement, velocity, and acceleration signals of the sprung and unsprung masses of the suspension system.

6. A method for controlling the suspension according to claim 1, characterized in that, Includes the following steps: The suspension controller collects real-time motion state data of the suspension system from the sensors; Based on the state data, the suspension controller outputs a control signal to the motor actuator according to a certain control algorithm; Under the control signal, the motor-driven actuator drives the hydraulic actuator to move through hydraulic transmission, thereby achieving active control of the suspension system.

7. The method according to claim 6, characterized in that, The signals output by the sensor include: displacement, velocity, and acceleration signals of the sprung and unsprung masses of the suspension system.

8. The method according to claim 6, characterized in that, Under good road conditions, the control motor actuator stops working, and the hydraulic actuator achieves passive control of the suspension system.

Images