RU2548823C2 - Method and system of vehicle cushioning - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to suppression of vehicle body oscillations at various road conditions. Proposed system comprises resilient and damping elements installed at vehicle body and articulated with suspension rockers. Damping elements are composed by two-mode moment blade hydraulic cylinders to be operated in controlled and uncontrolled modes. Mode changeover units are connected to unlike working chambers of hydraulic cylinders via throttle, check valve and hydraulic booster control valve. For cushioning, suspension damping properties are used to decreased angular and vertical oscillations of the body. In motion, current angular deviations and angular velocities of the body are measured in lengthwise and crosswise plane and vertical velocities of the body centre of gravity. Current required control force acting on the wheel via suspension is calculated. Then control system converts said damping elements into actuators to create control action at the wheel.

EFFECT: efficient control over suspension subject to road conditions.

2 cl, 3 dwg

Description

The invention relates to methods and devices for reducing fluctuations in vehicle bodies when road conditions change, controlling the effect on the body through a suspension equipped with devices for regulating its characteristics.

Known chassis of the tractor [1], including a skeleton connected to a caterpillar mover having idler and drive wheels connected to corresponding mechanisms and covered by tracks interacting with track rollers, the skeleton being mounted with the possibility of changing its position relative to the caterpillar mover by means of a hydraulic cylinder, a cavity which, by means of a hydraulic registration mechanism, deviations of the core from a horizontal position are communicated with the pump. At the same time, in the front part of the skeleton, by means of a corresponding axis located in the plane of symmetry of the tractor chassis, it is connected with the balancer and sprung with torsion bars relative to the tension wheels, and the back of the skeleton is communicated with the drive axle via an axis connected also to it, also located in the said plane installed in a vertical groove of the eye, rigidly mounted on the frame.

The disadvantage of this device is the low speed of the device changes the position of the housing relative to the caterpillar mover, which is unacceptable for vehicles.

A known device for regulating the resistance forces of shock absorbers [2], including an automatic regulator and controllable shock absorbers, characterized in that it is additionally equipped with controllable shock absorbers on medium vehicle suspensions, an automatic regulator and a speed sensor with the ability to change the resistance of shock absorbers depending on the vehicle speed .

The disadvantage of this device is that there is no relationship between the speed of the vehicle and the real profile of the road, which reduces the efficiency of the device.

Known control system active suspension of the vehicle [3].

The invention relates to active suspensions of vehicles, in particular to devices for controlling active suspensions. Essence: the device contains sensors 1-5 angles of longitudinal and transverse rolls, changes in the statistical weight of the sprung part, vehicle speed and forces acting from the wheel suspensions on the sprung part, blocks 9, 10 for determining longitudinal and lateral stability and block 11 for generating uniform signals load distribution between active wheel suspensions. According to the readings of the force sensors acting from the suspensions on the sprung part, the vehicle speed and longitudinal acceleration sensors of the vehicle, control signals for active wheel suspensions are generated, which are adjusted in accordance with the signals of the sensors of the angles of longitudinal and transverse roll and changes in statistical weight. Actuators are controlled by a unit for generating uniform distribution signals between active wheel suspensions.

The disadvantage of this device is that despite the similarity of approaches to solving the problem of active suspension, this design relates to wheeled multi-support vehicles.

The invention is known [4], which relates to transport engineering, in particular to multi-support vehicles with an active controlled suspension system. It includes a method for damping vertical vibrations of a multi-support vehicle body, which consists in recovering the energy of vertical body vibrations in suspensions of medium supports, converting it into pressure energy, accumulating it, and then transferring extreme supports to the suspension system, where an additional stabilizing moment is created, reducing angular vibrations of the body. The design that implements the proposed method contains hydraulically controlled suspensions of extreme wheels and uncontrolled suspensions of medium supports equipped with a system for recovering energy directed to the suspension of extreme supports. This increases the efficiency of damping oscillations and reducing energy consumption. The disadvantage of the design is that an additional stabilizing moment is created only by extreme suspensions. Measurement of the current components of the movement - the actual inclination angles, angular velocities and vertical displacements of the center of mass of the machine - is not performed, but is carried out only upon their occurrence.

Despite this latest invention, in its technical essence, it is most closely proposed and adopted as a prototype.

The task of the invention is to improve the performance of the suspension system. EFFECT: control of a suspension system depending on road conditions at specified permissible vibration parameters at a current time.

The problem is solved in that a new method of suspension of the vehicle is proposed, which consists in using the damping properties of the suspensions to reduce the angular and vertical vibrations of the body. At the same time, while the vehicle is moving, the current angular deviations and the angular velocities of its body in the longitudinal and transverse planes, as well as the vertical speeds of its center of mass, are measured, the suspension modes are selected - uncontrolled when the body vibrations are less than permissible for the given driving conditions, and controlled when the vibrations bodies are higher than permissible, in the latter case, the current required value of the power control action on the wheel through the suspension is calculated according to the expression

, $$P_{\mathrm{at}PR}=k\mathrm{one}\varphi +k2\dot{\varphi }+k3\gamma +k\mathrm{four}\dot{\gamma }+k5\dot{z}$$

,

where φ, γ are the angles of oscillation of the body in the longitudinal and transverse planes, respectively, radian,

, $$\dot{\gamma }$$

- угловые скорости колебаний кузова в продольной и поперечной плоскостях соответственно, радиан/с, $$\dot{\varphi }$$

, $$\dot{\gamma }$$

- the angular velocity of oscillation of the body in the longitudinal and transverse planes, respectively, radian / s,

- вертикальная скорость центра масс кузова, м/с, $$\dot{z}$$

- vertical velocity of the center of mass of the body, m / s,

, $$k2\frac{кНс}{радиан}$$

, $$k3\frac{кН}{радиан}$$

, $$k4\frac{кНс}{радиан}$$

, $$k5\frac{кНс}{м}$$

- коэффициенты усиления по соответствующим параметрам и размерности. $$k\mathrm{one}\frac{\mathrm{to}N}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k2\frac{\mathrm{to}N\mathrm{from}}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k3\frac{\mathrm{to}N}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k\mathrm{four}\frac{\mathrm{to}N\mathrm{from}}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k5\frac{\mathrm{to}N\mathrm{from}}{m}$$

- gains according to the relevant parameters and dimensions.

then, by the influence of the control system, the damping elements of the suspensions are transformed into actuators and form with their help the required control force on the wheel.

The switching of operating modes, namely the transition from uncontrolled mode to a controlled moment, occurs automatically or manually.

To implement the method, the applicant has proposed a vehicle suspension system containing elastic and damping elements mounted on a car body and kinematically connected with suspension balancers. Its damping elements are made in the form of dual-mode momentary vane hydraulic cylinders with the possibility of controlled and uncontrolled modes of operation, each of which is connected by hydraulic communication with the hydraulic pump and the suspension control system, equipped with a compensation chamber, suction and non-return valves, safety valves, while to the opposite working cavities hydraulic cylinders sequentially one after another through the throttle and check valve, as well as the power distributor switch blocks are connected Mode Ia.

Figure 1 shows the design of the suspension system, and figure 2 - its basic electro-hydraulic control circuit of hydraulic vane cylinders. Figure 3 shows a General view of a hydraulic vane cylinder.

The suspension system consists of elastic elements - torsion shafts 1 installed in the vehicle body 2 and kinematically connected through the balancers 3 of the suspensions of the support wheels 4 and the rod 5 with a hydraulic blade hydraulic cylinder 6.

The latter is made in the form of a dual-mode torque hydraulic cylinder, consisting of a housing 7, inside of which a rotor 8 with blades 9 and 10 is installed, which together with the partitions 11 and 12 form the working chambers 13 and 14. The rotor 8 is equipped with a lever 15 connected by a rod 5 to the balancer 3 support wheels 4.

Pressure chambers 16 and 17 are installed in the working chambers 13 and 14. The compensation chamber 18 located on the body 7 is directly connected through the suction disk valves 19 and 20 to the lower cavities of the working chambers 13 and 14, and to the upper cavities through the suction valves 21 and 22, located in the upper partition 11 and connected to the channel 23 drain fluid. In the partitions 11 and 12, disc pressure valves 24 and 25 are installed, respectively, reverse and forward, which are hydraulically connected with blocks 26 and 27 switching modes of operation of the hydraulic vane hydraulic cylinder 6.

The mode switching units 26 and 27 are connected in series with each other via an inductor 28 and a check valve 29. Each unit is hydraulically connected with its shut-off spring-loaded valve 30 to a pump station 31 and an electric power amplifier 32 controlled by a control system 33.

The control system 33 provides the ability of the hydraulic vane hydraulic cylinder 6 to operate in both controlled and uncontrolled modes. Uncontrolled mode is carried out by turning off the control system 33 of the hydraulic actuator - pump station 31. In this case, a pressure drop occurs in the supply line 34 and shut-off valves 30 under the action of their springs, occupying the leftmost position, block the hydraulic connection of the electric power booster 32 with the operating mode switching units 26 and 27 and hydraulic vane hydraulic cylinder 6.

The latter begins to work as a paddle hydraulic shock absorber, the speed characteristics of which are formed due to the flow of the working fluid: in the forward stroke - from the forward working chamber 14 through the throttle 28 to the reverse working chamber 13, and in the reverse stroke - from the working chamber 13 through the throttle 28 and a valve 29 into the forward stroke chamber 14.

With an increase in the volume of liquid in the working chambers 13 and 14 due to heating during prolonged operation of the hydraulic vane hydraulic cylinder 6, the liquid is discharged into the compensation chamber 18 through valves 19 and 20. With a lack of liquid in the working chambers 13 and 14, suction from the compensation chamber 18 occurs poppet valves 21 and 22.

When the body 2 of the machine deviates from its static position by an angle greater than the specified value, the control system 33 starts to operate in controlled mode and turns on the hydraulic actuator 31 and generates an electric signal of a certain polarity and voltage corresponding to this instantaneous deviation to the electric power booster 32. This creates a force on the support wheel 4 desired directions.

As a result of the hydraulic actuator 31, the shut-off valves 30 of the operating mode switching blocks 26 and 27, compressing the springs of the valves 30, move to the extreme right position and cut off the hydraulic connection of the working chambers 13 and 14 with the valve 29 and the throttles 28, thereby opening the connection of the working chambers 13 and 14 with an electric hydraulic booster 32 and a hydraulic actuator 31. In this case, the hydraulic vane hydraulic cylinder 6 operates as a torque hydraulic cylinder. The force acting on the suspension appears as a result of the resulting pressure drop between the working chambers 13 and 14 and is formed in accordance with the selected control law

, $$P_{\mathrm{at}PR}=k\mathrm{one}\varphi +k2\dot{\varphi }+k3\gamma +k\mathrm{four}\dot{\gamma }+k5\dot{z}$$

,

where φ, γ are the angles of oscillation of the body in the longitudinal and transverse planes, respectively, radian,

, $$\dot{\gamma }$$

- угловые скорости колебаний кузова в продольной и поперечной плоскостях соответственно, радиан/с, $$\dot{\varphi }$$

, $$\dot{\gamma }$$

- the angular velocity of oscillation of the body in the longitudinal and transverse planes, respectively, radian / s,

- вертикальная скорость центра масс кузова, м/с, $$\dot{z}$$

- vertical velocity of the center of mass of the body, m / s,

, $$k2\frac{кНc}{радиан}$$

, $$k3\frac{кН}{радиан}$$

, $$k4\frac{кНс}{радиан}$$

, $$k5\frac{кНс}{м}$$

- коэффициенты усиления по соответствующим параметрам и размерности. $$k\mathrm{one}\frac{\mathrm{to}N}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k2\frac{\mathrm{to}Nc}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k3\frac{\mathrm{to}N}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k\mathrm{four}\frac{\mathrm{to}N\mathrm{from}}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k5\frac{\mathrm{to}N\mathrm{from}}{m}$$

- gains according to the relevant parameters and dimensions.

The feedback of the executive body of the control system 33 is carried out by monitoring the actual fluid pressure inside the working chambers 13 and 14 by pressure sensors 16 and 17, the signals of which enter the control system 33 and are summed with the signal of the current position of the vehicle body 2. When one of the working chambers 13 (14) reaches the fluid pressure corresponding to the beginning of the opening of the valves 24 (25) located in the partitions 11 and 12 of the hydraulic vane hydraulic cylinder 6, the pressure valve 24 (25) opens.

While ensuring the required position of the vehicle body 2, the hydraulic vane hydraulic cylinder 6, depending on road conditions, operates in a predetermined mode or switches to uncontrolled mode.

The applicant has developed an experimental design of the device, which confirmed the claimed benefits.

Literature

1. Application No. 99107097/13, Crawler tractor chassis, 1999

2. RF application No. 2003103501/11, Automatic device for regulating the resistance forces of shock absorbers, 2003

3. RF patent No.2019438, Active suspension control system of a vehicle, B60G 25 / 00.1991

4. RF patent No. 2041080, Method for damping oscillations of a multi-support vehicle, 1995 (prototype).

Claims (2)

1. The method of suspension of the vehicle, which consists in using the damping properties of the suspensions to reduce the angular and vertical vibrations of the body, which consists in the fact that while the vehicle is moving, the current angular deviations and the angular speeds of its body are measured in the longitudinal and transverse planes, as well as vertical speeds of its center of mass, choose the modes of suspension - uncontrolled, with body vibrations less than the permissible conditions of movement, and controlled, with body vibrations higher than permissible, in the latter case, the current required value of the power control action on the wheel through the suspension is calculated according to the expression:
$$P_{\mathrm{at}PR}=k\mathrm{one}\varphi +k2\dot{\varphi }+k3\gamma +k\mathrm{four}\dot{\gamma }+k5\dot{z}$$

,
where φ, γ are the angles of oscillation of the body in the longitudinal and transverse planes, respectively, radian;
$$\dot{\varphi }$$

, $$\dot{\gamma }$$

- the angular velocity of oscillation of the body in the longitudinal and transverse planes, respectively, radian / s;
$$\dot{z}$$

- vertical velocity of the center of mass of the body, m / s,
$$k\mathrm{one}\frac{\mathrm{to}N}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k2\frac{\mathrm{to}Nc}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k3\frac{\mathrm{to}N}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k\mathrm{four}\frac{\mathrm{to}N\mathrm{from}}{R\mathrm{but}d\mathrm{and}\mathrm{but}n}$$

, $$k5\frac{\mathrm{to}N\mathrm{from}}{m}$$

- gains according to the relevant parameters and dimensions,
then, by the control action of the control system, the damping elements of the suspensions are transformed into actuators and form with their help the required control force on the wheel. 2. A vehicle suspension system containing elastic and damping elements mounted on a car body and kinematically connected with suspension balancers, while the damping elements are made in the form of dual-mode moment bladed hydraulic cylinders with the possibility of controlled and uncontrolled modes of operation, each of which is connected by hydraulic communication with hydraulic pump and suspension control system, equipped with a compensation chamber, suction and non-return valves, safety valves, while to heteronymic working cavities of hydraulic cylinders one after the other through a throttle and a check valve, and the power-steering valve connected mode switching units.

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