CN110775046B

CN110775046B - Vehicle rollover prevention control system and rollover prevention control method

Info

Publication number: CN110775046B
Application number: CN201911005437.3A
Authority: CN
Inventors: 付德春; 傅直全; 宋小毅; 张磊; 贺迎春
Original assignee: Zhejiang VIE Science and Technology Co Ltd
Current assignee: Zhejiang VIE Science and Technology Co Ltd
Priority date: 2019-10-22
Filing date: 2019-10-22
Publication date: 2023-02-17
Anticipated expiration: 2039-10-22
Also published as: CN110775046A

Abstract

The invention relates to the field of vehicle rollover prevention, and discloses a vehicle rollover prevention control system and a vehicle rollover prevention control method, which comprise a main controller, a suspension system and a braking system, wherein the vehicle is a full trailer or a semi-trailer or a middle-mounted axle trailer or a tractor or a truck or a light truck or a passenger car or a rail vehicle, the control system also comprises a wheel speed acquisition module, a suspension load acquisition module, a lateral acceleration acquisition module and a vehicle body inclination acquisition module; the wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module are electrically connected with the main controller, and the main controller performs rollover prevention adjustment on the suspension system and the braking system according to signals transmitted by the wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module. The reliable and timely rollover trend is obtained by weighting and fusing multiple parameters, so that accurate and timely rollover prevention suggestions and rollover prevention strategies are provided for users, the user experience is better, and the driver cannot be interfered too early or too late.

Description

Vehicle rollover prevention control system and rollover prevention control method

Technical Field

The invention relates to the field of vehicle rollover prevention, in particular to a vehicle rollover prevention control system and a vehicle rollover prevention control method.

Background

Because of large mass and high gravity center, the load-carrying vehicle, especially the load-carrying trailer, is easy to turn over if the speed or steering control is not proper when the vehicle runs on a curve, and is a major cause of the current traffic accidents. The present method and apparatus related to vehicle Rollover Stability Control (RSC) mainly monitor the rollover tendency of a vehicle based on the lateral acceleration of the vehicle or the load transfer rate of the wheels on both sides of the vehicle, and perform warning or braking intervention when the above-mentioned monitoring signal exceeds a rollover threshold. For the braking intervention, the known technology also comprises rollover test braking, namely, short and slight braking is carried out and the wheel speed change of the inner wheel is detected, if the wheel speed is obviously reduced, the inner wheel is judged to have no load basically or to be about to lift off/lift off, and then the rollover prevention braking intervention is immediately carried out, so that the vehicle is braked greatly to reduce the vehicle speed. The prior art also includes asymmetric braking of the wheels on both sides, i.e. braking is applied only to the wheels on the outside, so as to generate a moment for returning the vehicle to the right, so as to more effectively reduce the risk of rollover.

In a known method for determining a rollover tendency based on a lateral acceleration or an equivalent lateral acceleration of a vehicle (e.g., a difference between wheel speeds of inner and outer wheels), a rollover threshold is determined, and the rollover trigger threshold is directly related to a height of a center of gravity of the vehicle. CN105517863A — method for stabilizing the running characteristics of a vehicle combination and a running dynamics adjusting apparatus disclose a method for estimating the height of the center of gravity of a vehicle, which is approximated mainly by the axle load and the characteristics of the vehicle, and the axle load is estimated by the relationship between the pressure of an air suspension support bag or the output power of an engine and the actual acceleration of the vehicle.

In a known method for monitoring a vehicle rollover trend based on Load Transfer rates of wheels on two sides of a vehicle, a suspension height sensor or a suspension deformation displacement sensor is generally adopted to measure wheel equivalent actual loads, or a signal processing of a triaxial angular velocity sensor is used to obtain a wheel equivalent actual Load Transfer Rate (LTR), and when the loads on two sides of the vehicle are obviously transferred and exceed a certain threshold value, an anti-rollover Rate is triggeredAnd (5) controlling rollover. CN108394406A — heavy-duty vehicle rollover-prevention warning system based on load sensing and active braking discloses a method for measuring load/support reaction force of each suspension through front, rear, left and right suspension displacement sensors (height sensors) and calculating load transfer rate LTR, and setting a rollover warning threshold value when LTR =0.8 and a rollover-prevention control threshold value when LTR = 0.9. CN 108909704A-A vehicle rollover prevention control method based on Internet of vehicles discloses a method, which includes obtaining an optimal real-time roll angle through three-axis angular velocity integral and Kalman filtering, then calculating a transverse load transfer rate LTR by using lateral acceleration, predicting the LTR for 1-2 seconds through a multilayer hierarchical modeling prediction method, and setting the time of LTR>The vehicle 1 is in a rollover dangerous state, and the vehicle is stabilized through active steering and asymmetric braking. CN109368076A, a rollover prevention control system and a rollover prevention control method for a tank truck disclose a method, which comprises the steps of measuring the attitude of the tank body by using four displacement sensors (arranged on four corner brackets of the tank body of a vehicle), measuring the side inclination angle of a rear axle by using two displacement sensors (arranged below a rear axle of a trailer), measuring the height of the mass center of liquid in the tank body by using one liquid level sensor, calculating the difference between the height of the static mass center and the height of the dynamic mass center of the vehicle according to the measured values, and setting two threshold values K ₁ (tank in contact with Chassis) and K ₂ (wheel off side) as a warning threshold for rollover and a threshold for implementing anti-rollover braking intervention, respectively.

For the judgment of the rollover tendency, the prior art does not perform fusion processing on the lateral acceleration (or equivalent lateral acceleration, such as wheel speed difference of inner and outer wheels) of the vehicle or the lateral load transfer rate (roll angle) based on the lateral acceleration or the equivalent lateral acceleration or the wheel speed difference of the inner and outer wheels, or does not consider the dynamic characteristics and the influence of the vehicle in the actual running process.

In the prior art, the rollover triggering threshold based on lateral acceleration is directly related to the height of the gravity center of the vehicle, the height of the gravity center is estimated approximately mainly by using the axle load and the characteristics of the vehicle, and the axle load is estimated according to the relation between the pressure of an air suspension support air bag or the output power of an engine and the actual acceleration of the vehicle, so that the accuracy cannot be ensured, and errors and even opposite judgment and control can be generated under some special working conditions, such as uneven road surfaces, slopes, turning inclined lanes and the like. In addition, the rollover threshold value of the lateral acceleration is calculated in the prior art as a static calculation process, that is, under the condition that the vehicle parameters and the load are not changed, the threshold value is also not changed, and thus the situation is not met. For example, the risk of vehicle rollover at the same lateral acceleration is clearly different at different vehicle speeds, or at different vehicle roll angles. An extreme case is when a vehicle load is unevenly distributed, a static lateral offset load occurs, which does not respond equally well to a change in lateral acceleration, and a small lateral acceleration may cause the vehicle to roll over to the offset side if the vehicle is driving in a curve and turning in the opposite direction of the offset load.

Also, the prior art rollover triggering threshold, which is based on load transfer rate or roll angle, is directly related to the stiffness of the suspension itself and the initial static imbalance condition, and for air suspensions the equivalent stiffness is a variable value related to the load magnitude, whereas the prior art directly sets it to a constant or equivalent constant, ignoring the dynamics of the suspension. In addition, in the prior art, the load transfer rate or the roll angle is measured and estimated only by a suspension height sensor or a deformation displacement sensor, while the lateral acceleration is often prior to the deformation of the suspension in the actual steering process of the vehicle, and the deformation of the suspension is only reflected by the phenomenon after the transient process occurs, so that the method has hysteresis effect.

For rollover-prevention intervention control, the prior art is implemented primarily by braking and steering interventions, and for trailers only by braking or asymmetric braking interventions. The timing of the above intervention is often paradoxical: premature braking interventions, in particular test braking in the known art, can affect the normal driving of the vehicle and even disturb the driver's judgment of the vehicle state, whereas too late braking interventions may not work at all, since the driver is likely to have already judged that the vehicle is abnormally driven and to take corresponding steering or braking measures, or if late, to be impossible to avoid the vehicle from rolling over.

Disclosure of Invention

In order to avoid the problems in the existing rollover prevention control technology, further improve the accuracy and the application range of rollover trend judgment and improve the rollover prevention control effect, the invention provides a rollover trend judgment and rollover prevention control method for a vehicle, particularly a trailer, based on an electric control air suspension, and a control system and an alarm device adopting the method. The invention has the core idea that the rollover trend of the vehicle is judged by utilizing the dynamic characteristic quantities of various signals to carry out weighting fusion, rollover stable control is intervened in the early rollover stage, the control does not influence the normal running of the vehicle, does not interfere the judgment of the vehicle state by a driver, and alarms are sent to related personnel and other vehicles around the vehicle under the unavoidable extreme condition of the vehicle rollover, so that the harm caused by the vehicle rollover is reduced to the maximum extent. A vehicle rollover prevention control system and a rollover prevention control method are provided.

In order to solve the technical problem, the invention is solved by the following technical scheme:

a vehicle rollover prevention control system comprises a main controller, a suspension system and a braking system, wherein the vehicle is a full trailer or a semi-trailer or a middle-mounted axle trailer or a tractor or a truck or a light truck or a passenger car or a rail vehicle, and the control system also comprises a wheel speed acquisition module, a suspension load acquisition module, a lateral acceleration acquisition module and a vehicle body inclination acquisition module; the wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module are electrically connected with the main controller, and the main controller performs rollover prevention adjustment on the suspension system and the braking system according to signals transmitted by the wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module.

Preferably, the device also comprises an alarm device, and the main controller controls the alarm device according to signals transmitted by the acquisition wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module; the main controller is electrically connected with the height sensor and the air suspension support air bag pressure sensor, and calculates the current actual load of the suspension according to signals transmitted by the height sensor and the air suspension support air bag pressure sensor; the vehicle further comprises a lateral acceleration sensor electrically connected with the main controller, and the lateral acceleration sensor is used for collecting lateral acceleration signals of the vehicle.

Preferably, the suspension system is an air suspension system, the air suspension system comprises an air suspension air bag, an air suspension electric control valve and an air suspension air storage cylinder, the air suspension electric control valve is used for adjusting the pressure of the air supporting air bag, the suspension load acquisition module comprises an air suspension supporting air bag pressure sensor used for detecting the pressure of the air suspension air bag, and the main controller is electrically connected with the air suspension supporting air bag pressure sensor and the air suspension electric control valve to acquire the state of the air suspension to control the air suspension electric control valve; the vehicle body inclination acquisition module is a suspension height sensor, the wheel speed acquisition module is a wheel speed sensor, and the lateral acceleration acquisition module is a lateral acceleration sensor.

Preferably, the braking system is a compressed air electronic braking system, the compressed air electronic braking system comprises an electric control unit, a brake air chamber regulator, an air pressure joint, a brake and a braking air storage cylinder, the electric control unit and the brake air chamber regulator are electrically connected with a main controller, and the main controller performs closed-loop regulation on the braking pressure of the controller according to a braking request electric signal of a CAN bus or an air pressure signal of the braking request air pressure joint; the electric control unit and the brake air chamber regulator are integrated on the main controller, the brake system further comprises a rear axle EBS regulator electrically connected with the main controller, and the main controller performs closed-loop regulation on service braking of the rear axle double-cavity brake through the rear axle EBS regulator.

The invention also provides a vehicle rollover prevention judgment and control method, which comprises the following steps,

s1, obtaining fixed parameters of a vehicle,

s2, obtaining static parameters of the vehicle; the static parameters are parameters used for evaluating the rollover trend in the vehicle parameters in a static state or a uniform linear driving state, and the static parameters are used as the reference for evaluating the rollover trend;

s3, acquiring dynamic parameters of the vehicle, and comparing the dynamic parameters with the static parameters in the step S2 to acquire dynamic characteristic quantities;

s4, acquiring the current weighting coefficient of each dynamic characteristic quantity according to the state of the vehicle;

s5, calculating a current rollover trend characteristic quantity K according to the dynamic characteristic quantity and the current weighting coefficient of each dynamic characteristic quantity;

and S6, different rollover threshold values are preset by the system, the different rollover threshold values correspond to different rollover prevention methods, the threshold value range of the current rollover prevention characteristic quantity K is compared, and the vehicle makes different rollover prevention instructions. The rollover prevention trend is judged according to various characteristic parameters and various states of the vehicle, so that the judgment reasonability and the judgment accuracy are improved.

Preferably, the solid-state parameters of the vehicle are parameters having an influence on the side overturning, including vehicle weight, maximum load, number of axles, number of tires, track, tire size, brake input/output characteristics, mounting position and rigidity characteristics of air suspension support air bags, output characteristics of air suspension pressure sensors, output characteristics of air suspension electric control valves, output characteristics of suspension height sensors, mounting position and output characteristics of lateral acceleration sensors, and the fixed parameters of the vehicle are solidified in software of a main controller of the vehicle or in a calibration file written into the main controller. These parameters are the information directly acquired by the sensor and are the basic parameters of the sensor.

Preferably, the partial rollover prevention related static parameters in the step S2 include the actual weight of the vehicle, the height of the center of mass, the static unbalance rate, the suspension stiffness and the static deviation of the lateral acceleration. The static driving state of the vehicle is collected, so that reliable basic parameters can be obtained, and calculation of dynamic characteristic quantity is facilitated.

Preferably, the static parameters of the vehicle in step S2 include at least two of air suspension static height, air suspension strut air bag static air pressure, lateral acceleration and wheel speed. The rollover prevention state of the vehicle is predicted by adopting various parameters, so that rollover prevention reference can be accurately and reliably provided, accurate rollover prevention action is convenient to provide, and the rollover prevention action is prevented from being misjudged to influence a driver.

Preferably, the static parameters of the vehicle include air suspension static height, air suspension support air bag pressure and lateral acceleration, the dynamic characteristic quantities obtained in step S3 are defined as Ka, kh, kp, kv, wa, wh, wp, wv and Wv, and the rollover trend characteristic quantity K in step S5:

the reasonable rollover trend characteristic quantity K can be obtained by weighting each dynamic characteristic quantity, and the rollover trend characteristic quantity K is compared with different thresholds, so that the degree of the rollover trend of the vehicle is judged, and the controller judges whether the rollover prevention action needs to be executed at present and what rollover prevention action needs to be executed; defining a suspension adjustment threshold value of K ₁ When the rollover trend characteristic quantity K exceeds the suspension regulation threshold value K ₁ The main controller implements air suspension height adjustment through an air suspension electric control valve: the outer suspension strut air bag is pressurized, and the inner suspension strut air bag is depressurized.

Preferably, the driver warning threshold is defined as K ₂ When the rollover trend characteristic quantity K exceeds the suspension regulation threshold value K ₂ If the alarm is not detected, the main controller controls the alarm device to give an alarm; defining an active braking intervention threshold value as K ₃ When the rollover trend characteristic quantity K exceeds the suspension regulation threshold value K ₃ The main controller controls the brake to apply the braking operation; defining a rollover unavoidable alarm threshold K ₄ When the rollover trend characteristic quantity K exceeds the overhangShelf adjustment threshold K ₄ And the main controller gives an alarm by controlling the alarm device.

According to the invention, due to the adoption of the technical scheme, the rollover trend of the vehicle is judged by utilizing the dynamic characteristic quantities of various signals to carry out weighting fusion, rollover stable control is involved in the early rollover stage, the control does not influence the normal running of the vehicle and cannot cause interference on the judgment of the vehicle state by a driver, and under the unavoidable extreme condition of the vehicle rollover, related personnel around the vehicle and other vehicles are sent out alarms, so that the harm caused by the vehicle rollover is reduced to the maximum extent.

Drawings

FIG. 1 is a schematic diagram of the component connections of the control system.

Fig. 2 is a schematic structural diagram of a rollover prevention trend determination and rollover control method.

Fig. 3 is a control schematic of the control system.

Graph marking table

1. Tractor vehicle

2. Trailer

3. Main controller of trailer

4. Air suspension support air bag pressure sensor

5. Air suspension support airbag

6. Suspension height sensor

7. Wheel speed sensor

8. Double-chamber brake (Integrated service brake and parking brake)

9. Brake

10. Tyre

11. Emergency relay valve

12. Braking air cylinder

13. Air storage cylinder of air suspension

14. Overflow valve

15. Air suspension electric control valve

16. Rear axle EBS regulator

17. Overload protection valve (anti-overlapping valve)

18. Side alarm relay

19. ISO 7638 joint

20. Brake lamp joint (ISO 118524N)

21. Brake control pneumatic connector

22. Brake air supply joint

23. Tractor braking main controller

24. Brake lamp power supply deconcentrator

25. Electrical connection of the trailer master controller 3 to the rear axle EBS controller 16

26. Electrical connection of trailer main controller 3 and air suspension electric control valve 15

27. Rear alarm relay

31. A lateral acceleration sensor (integrated in the trailer master controller).

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Example 1

The present embodiment describes the core idea of the present invention by taking a typical two-axle full trailer with an air suspension and a compressed air brake system 302 as an example, but does not represent that the present invention is limited to the described vehicle type, and those skilled in the art can easily apply the present invention to other various vehicle types and perform corresponding adaptation processing according to the description herein.

The embodiment provides a vehicle rollover prevention control system, which comprises a main controller 3, a suspension system 301, a brake system 302, a wheel speed acquisition module 303, a suspension load acquisition module 304, a lateral acceleration acquisition module 305 and a vehicle body inclination acquisition module 306; the wheel speed acquisition module 303, the suspension load acquisition module 304, the lateral acceleration acquisition module 305 and the vehicle body inclination acquisition module 306 are electrically connected with the main controller 3, and the main controller 3 performs rollover prevention adjustment on the suspension system 301 and the brake system 302 according to signals transmitted by the wheel speed acquisition module 303, the suspension load acquisition module 304, the lateral acceleration acquisition module 305 and the vehicle body inclination acquisition module 306. The rollover prevention control system further comprises an alarm device 307, and the main controller controls the alarm device 307 according to signals transmitted by the collecting wheel speed collecting module 303, the suspension load collecting module 304, the lateral acceleration collecting module 305 and the vehicle body inclination collecting module 306. Wherein the warning device 307 includes an indoor warning device for reminding a driver in the cab and a warning device 307 for warning surrounding vehicles and pedestrians on the outside of the vehicle body. The suspension system 301 is an air suspension system 301, the air suspension system 301 comprises an air suspension airbag, an air suspension electric control valve 15 for adjusting the pressure of the air support airbag and an air suspension air storage cylinder 13, the suspension load acquisition module 304 comprises an air suspension support airbag pressure sensor 4 for detecting the pressure of the air suspension airbag, and the main controller 3 is electrically connected with the air suspension support airbag pressure sensor 4 and the air suspension electric control valve 15 to acquire the state control air suspension electric control valve 15 of the air suspension; the body inclination acquisition module 306 is a suspension height sensor 6, the wheel speed acquisition module 303 is a wheel speed sensor 7, and the lateral acceleration acquisition module 305 is a lateral acceleration sensor 31.

The brake system 302 is a compressed air electronic brake system EBS, the compressed air electronic brake system 302 comprises an electric control unit, a brake air chamber regulator, an air pressure joint 21, a brake 9 and a brake air storage cylinder 12, the electric control unit and the brake air chamber regulator are electrically connected with the main controller 3, and the main controller 3 carries out closed-loop regulation on the brake pressure of the controller according to a brake request electric signal of a CAN bus or an air pressure signal of the brake request air pressure joint 21; the electric control unit and the brake chamber regulator are integrated on the main controller 3, the brake system 302 further comprises a rear axle EBS regulator 16 electrically connected with the main controller 3, and the main controller 3 performs closed-loop regulation on service braking of the rear axle dual-chamber brake 9 through the rear axle EBS regulator 16.

Specifically, as shown in the drawings, 1 is a tractor (not specifically shown) and 2 is a trailer, and in this example, the tractor 1 and the trailer 2 both employ a compressed air Electronic Brake System 302 (EBS). Reference numeral 23 is the tractor's brake master controller which is electrically connected to the trailer's master controller 3 via the well known ISO 7638 connector 19 to provide the master controller 3 with power supply, alarm indication port and CAN communication interface. The tractor vehicle also controls the stop lights of the trailer 2 via a stop light connection (ISO 118524N) 20, and the trailer 2 switches the brake light supply via a stop light supply tap 24 into the trailer master controller 3 in order to provide it with a backup power supply in case of disconnection or failure of the ISO 7638 connection 19. The tractor 1 supplies compressed air to the trailer 2 via the brake air supply connection 22 and transmits the driver's brake application pressure to the trailer master controller 3 via the brake control air pressure connection 21. The trailer main controller 3 receives the braking request electric signal transmitted by the CAN bus and the braking request air pressure signal transmitted by the braking control air pressure connector 21 at the same time, preferentially adopts the electric signal to brake the trailer, and adopts the air pressure signal to brake only when the electric signal is abnormal. Furthermore, if the electronic brake circuit of the trailer master controller 3 fails or fails, the trailer can still use the air pressure signal of the brake control air pressure connector 21 to implement the backup pressure brake, which is well known in the art and will not be described in detail herein. In addition, the compressed air supply line and the brake request air pressure line also enter an emergency relay valve 11, which emergency relay valve 11 enables the application and release of the trailer parking brake and the automatic braking of the trailer in the event of a leak or disconnection of the air supply line. Similarly, the above-described function of the emergency relay valve 11 is well known in the art and will not be described in detail herein.

The trailer master controller 3 integrates an electronic control unit of the trailer electronic brake system 302 (EBS) and a brake air pressure regulator, and performs closed-loop regulation of the brake pressure of the brakes 9 in response to a brake request electrical signal of the CAN bus or an air pressure signal of the brake request air pressure connection 21. Furthermore, an electrical connection 25 is provided between the trailer master controller 3 and the rear axle EBS controller 16, which controls the rear axle EBS controller 16 to perform closed-loop control of the service brake air pressure of the rear axle dual chamber brake 8. The compressed air required for trailer braking originates from the brake air reservoir 12. The trailer master controller 3 detects the actual rotational speed and slip rate of the tires via the wheel speed sensors 7 during the Brake adjustment and performs an Anti-lock Brake System (ABS) adjustment when the tires tend to lock.

The trailer main controller 3 is also electrically connected with the air suspension electronic control valve 15, the air pressure of the air suspension support air bag 5 can be adjusted, so that the height of the air suspension is adjusted, and the closed-loop adjustment is realized through the feedback signal of the suspension height sensor 6. In addition, the trailer master controller 3 monitors the actual pressure of the air bags through the air suspension support air bag pressure sensors 4 to sense the actual load of the suspension. The compressed air required for the air suspension regulation originates from an air suspension air reservoir 13, which air reservoir 13 is charged with compressed air supplied from the tractor 1 after passing through an overflow valve 14.

The trailer 2 also has an overload protection valve 17 (overlap prevention valve) which protects the dual chamber brake 8 against overload damage when service braking and parking braking are simultaneously carried out. Overload protection valves (anti-overlap valves) are also known in the art and will not be described in detail here.

When a vehicle runs on a curve, the load of the vehicle can be transferred to the outer wheels due to the action of centrifugal force, so that the outer suspension is dynamically compressed, the inner suspension is dynamically stretched, and the vehicle body inclines. Particularly for a truck or a truck trailer, the vehicle is easy to roll over if the vehicle speed and the steering control are not proper when the vehicle runs on a curve because of high gravity and large mass of the vehicle.

In order to avoid the rollover of the vehicle to the greatest extent, reduce the dangerous consequences caused by the rollover of the vehicle and overcome the defects of the existing rollover prevention technology described in the background art, the invention provides a rollover tendency judgment method, a rollover prevention control method and a rollover prevention control system on the basis of the illustrated typical vehicle brake system 302.

Fixed parameters of the trailer 2 are first acquired, which are determined by vehicle design and manufacture and are relevant to rollover prevention control, such as vehicle weight, maximum load, number of axles, number of tires, track width, tire size, brake input/output characteristics, mounting position and stiffness characteristics of an air suspension support bag, output characteristics of an air suspension pressure sensor, output characteristics of an air suspension electronic control valve, output characteristics of a suspension height sensor, mounting position and output characteristics of a lateral acceleration sensor, and the like. The fixed parameters are typically either embedded in the software of the trailer master controller 3 or written to a calibration file of the trailer master controller 3 by a diagnostic device when the vehicle is taken off-line.

Then when the vehicle is in a static state or runs at an approximately constant speed on a flat road surface in a straight line, the trailer main controller 3 acquires static parameters of the trailer 2, and the static parameters of the vehicle represent static characteristics of the vehicle and serve as a reference standard for calculating dynamic characteristic quantity in the running process of the vehicle. These static parameters include information directly collected from sensors including the static height of the air suspension, the static air pressure of the air suspension support airbag, the static output of lateral acceleration, and the anti-rollover related static parameters calculated in conjunction with the vehicle fixed parameters, such as but not limited to the actual weight of the vehicle, the equivalent estimated height of the center of mass, the lateral offset of the center of mass (static unbalance rate), the equivalent suspension stiffness, the equivalent lateral support lever length of the suspension support point, the static offset of lateral acceleration, and so on. Normally, the lateral acceleration signal of the vehicle is measured by a lateral acceleration sensor 31 integrated inside the trailer master controller 3, the lateral acceleration sensor 31 also being located outside the trailer master controller 3 and being electrically connected to the trailer master controller 3.

Then, in the dynamic driving process of the vehicle, particularly in the driving process of a curve, the trailer main controller 3 acquires the lateral acceleration, the air suspension height, the air bag pressure of the air suspension and a wheel speed signal of the vehicle, obtains the dynamic characteristic quantity of the signal on the basis of the static parameter of the vehicle, and then dynamically fuses the dynamic characteristic quantity to obtain the rollover tendency characteristic quantity K of the vehicle. The signal dynamic characteristic amount described here is a difference between a dynamic signal and a static value, and each characteristic amount may be normalized for the convenience of calculation. The dynamic characteristic quantity of each signal can be calculated by various methods, such as a linear difference, a linear ratio, a root mean square, a logarithmic difference and the like, and the specific calculation method is not limited in the invention, but each characteristic quantity can represent the rollover tendency or probability of the vehicle. The "contribution" of the dynamic characteristic amount of each signal to the rollover tendency characteristic amount K is not the same, and weighting processing should be performed. Generally, the weighting coefficient reflects the relevance of the dynamic characteristic quantity of the corresponding signal and the vehicle rollover, and the magnitude of the weighting coefficient depends on the rollover prevention related fixed parameters, the static parameters and the dynamic parameters of the vehicle. For example, the weighting factor of the lateral acceleration dynamic characteristic quantity must be larger when the vehicle is fully loaded than when the vehicle is empty or partially loaded, because the vehicle center of gravity is higher when the vehicle is fully loaded, the mass (inertia) is larger, the same lateral acceleration is more likely to cause the vehicle to roll over, and if the vehicle is traveling at a high speed at that time, a rollover accident is more likely to occur. Thus, the weighting coefficients may be fixed values, or more optimized dynamic values, or more complex neural network iteration results. Similarly, the calculation method of the weighting coefficient is not limited in the present invention, and the user can select and design according to the actual situation. The process of calculating the vehicle rollover tendency characteristic quantity K can be simply illustrated by the following formula:

in the formula, ka is a lateral acceleration dynamic characteristic quantity, kh is an air suspension height dynamic characteristic quantity, kp is an air suspension support air bag pressure dynamic characteristic quantity, kv is a wheel speed dynamic characteristic quantity, and Wa, wh, wp and Wv are dynamic weighting coefficients of the dynamic characteristic quantities respectively. The calculation result of the vehicle rollover tendency characteristic quantity K may trigger the following four types of anti-rollover control or warning, and these four types of conditions may be performed simultaneously or separately:

1) Suspension adjustment

And the trailer main controller 3 judges that the characteristic quantity K of the current vehicle rollover trend exceeds a suspension regulation threshold value K1, and then the air suspension height (rigidity) regulation is implemented through an air suspension electric control valve 15: the outer suspension support airbag is pressurized (suspension raised, stiffness strengthened) and the inner suspension support airbag is depressurized (suspension lowered, stiffness weakened). The suspension adjustment can not cause any influence on normal driving, and a driver can not even feel the adjustment, but has a very large anti-rollover effect, namely, the suspension adjustment intervenes in the vehicle body stability control in a very early stage and prepares for the anti-rollover.

2) Driver warning

And when the trailer main controller 3 judges that the characteristic quantity K of the current vehicle rollover trend exceeds a driver warning threshold value K2, a sound and light warning device in the cab warns the driver to inform the driver that the vehicle has rollover danger, and measures are immediately taken to properly control the speed and the steering of the vehicle so as to avoid further aggravation of the rollover danger. The warning message CAN be transmitted, for example, by the trailer master controller 3 via the CAN bus or the 5 th pin in the ISO 7638 connection 19 to the brake master controller 23 of the tractor 1 and the associated warning device (not shown) of the cab instrument desk is activated by the tractor brake master controller 23.

3) Active braking intervention

And the trailer main controller 3 judges that the current vehicle rollover trend characteristic quantity K exceeds an active braking intervention threshold value K3, actively intervenes for control, applies proper air pressure to service brake air chambers of the brake 9 and the double-chamber brake 8 and brakes the trailer 2. The braking mode can be bilateral symmetry or asymmetry braking in the prior art, aiming at reducing the speed and the lateral acceleration of the vehicle and avoiding the vehicle from rolling over. If a wheel locking tendency is detected at this point, the trailer master controller 3 should also make ABS adjustments. During an active braking intervention, if the driver takes over control, for example if the driver takes braking or steering measures, the trailer master controller 3 cancels the active intervention braking and gives control to the driver.

4) Unavoidable warning of rollover

When the trailer main controller 3 judges that the current vehicle rollover tendency characteristic quantity K exceeds the rollover unavoidable alarm threshold value K4, namely, the rollover is unavoidable anyway, the rollover unavoidable alarm information is transmitted to the brake main controller 23 of the tractor 1 through a CAN bus or a 5 th pin in the ISO 7638 connector 19, and the tractor brake main controller 23 activates a related warning device (not shown) of a cab instrument desk to remind a driver of preparing corresponding protection. Meanwhile, sound and light alarms are sent out in the front, the rear and the side of the vehicle to remind the surrounding related vehicles and people to avoid, so that the harm caused by the rollover accident is reduced to the maximum extent. The warning in front of the vehicle may be activated by the tractor brake master controller 23 activating the horn and headlights (not shown) of the tractor 1, the warning in the rear may be activated by the trailer's tail lights, brake lights, the rear warning relay 27 activated by the trailer master controller 3 flashing the brake lights or tail lights, and the warning in the side may be activated by the trailer master controller 3 controlling the side warning relay 18.

Example 2

The present embodiment is different from embodiment 1 in that: the brake system 302 employs other types of brake systems, such as vacuum brake systems or hydraulic brake systems or electric brake systems, instead of compressed air brake systems.

Example 3

The present embodiment is different from embodiment 1 in that: the application vehicle of the embodiment is a semitrailer or a central shaft trailer or a tractor or a truck or a light truck or a passenger car or even a rail vehicle and other vehicle types.

Example 4

The embodiment of the invention relates to a vehicle rollover prevention control system and a judgment control method, and is characterized in that: the suspension system 301 employs other types of suspension systems, such as leaf spring/mechanical suspension, gas-liquid suspension, etc., for which load sensing can be replaced by suspension deflection displacement instead of air suspension strut bladder pressure, eliminating suspension height (stiffness) adjustment (since mechanical/leaf spring suspensions cannot do height or stiffness adjustment).

Example 5

The present embodiment is different from embodiment 1 in that: the height sensor, the air bag pressure sensor and the wheel speed sensor are all arranged at 2 points, namely arranged at the left side and the right side of the vehicle.

Example 6

The present embodiment is different from embodiment 1 in that: the roll state of the vehicle body is measured by equivalently replacing a suspension height signal with a roll angular velocity signal or an integral signal thereof.

Example 7

The present embodiment is different from embodiment 1 in that: the lateral acceleration sensor is equivalently replaced by the product of the wheel speed difference or the yaw rate of the left side and the right side of the vehicle and the average vehicle speed to measure the lateral acceleration signal.

Example 8

The present embodiment is different from embodiment 1 in that: the pressure sensor is integrated in the trailer main controller 3 in whole or in part, and the corresponding air bag pressure is connected into the trailer main controller 3 for signal acquisition.

In summary, the above-mentioned embodiments are only preferred embodiments of the present invention, and all equivalent changes and modifications made in the claims of the present invention should be covered by the claims of the present invention.

Claims

1. The utility model provides a vehicle rollover prevention control system, includes main controller, suspension system and braking system, its characterized in that: the control system also comprises a wheel speed acquisition module, a suspension load acquisition module, a lateral acceleration acquisition module and a vehicle body inclination acquisition module; the wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module are electrically connected with the main controller, and the main controller performs rollover prevention adjustment on a suspension system and a brake system according to signals transmitted by the wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module; the vehicle rollover prevention method of the system comprises the following steps:

s1, obtaining fixed parameters of a vehicle;

s2, obtaining static parameters of the vehicle; the static parameters are parameters used for evaluating the rollover trend in vehicle parameters in a static state or a constant-speed straight-line running state of the vehicle, and the static parameters are used as a reference for evaluating the rollover trend;

s3, obtaining dynamic parameters of the vehicle, comparing the dynamic parameters with the static parameters in the step S2 to obtain dynamic characteristic quantity, wherein the dynamic characteristic quantity is the difference of the dynamic signal offset static parameters;

s6, different rollover thresholds are preset by the system, the different rollover thresholds correspond to different rollover prevention methods, the threshold range where the current rollover prevention characteristic quantity K is located is compared, and the vehicle makes different rollover prevention instructions;

the suspension system is an air suspension system, the air suspension system comprises an air suspension air bag, an air suspension electric control valve and an air suspension air storage cylinder, the air suspension electric control valve is used for adjusting the pressure of the air supporting air bag, the suspension load acquisition module comprises an air suspension supporting air bag pressure sensor used for detecting the pressure of the air suspension air bag, and the main controller is electrically connected with the air suspension supporting air bag pressure sensor and the air suspension electric control valve to acquire the state of the air suspension and control the air suspension electric control valve; the vehicle body inclination acquisition module is a suspension height sensor, the wheel speed acquisition module is a wheel speed sensor, and the lateral acceleration acquisition module is a lateral acceleration sensor; the static parameters of the vehicle comprise the static height of the air suspension, the air pressure of an air suspension supporting air bag, the lateral acceleration and the wheel speed, the dynamic characteristic quantity obtained in the step S3 is defined as Ka, kh, kp and Kv, the dynamic weighting coefficient of each dynamic characteristic quantity in the step S4 depends on the rollover prevention related fixed parameter, the static parameter and the dynamic parameter of the vehicle, wa is the dynamic weighting coefficient of the lateral acceleration dynamic characteristic quantity, wh is the dynamic weighting coefficient of the air suspension height dynamic characteristic quantity, wp is the dynamic weighting coefficient of the air suspension supporting air bag pressure dynamic characteristic quantity, wv is the dynamic weighting coefficient of the wheel speed dynamic characteristic quantity, and K is the rollover trend characteristic quantity in the step S5:

2. the vehicle rollover prevention control system according to claim 1, wherein: the main controller controls the alarm device according to signals transmitted by the acquisition wheel speed acquisition module, the suspension load acquisition module, the lateral acceleration acquisition module and the vehicle body inclination acquisition module; the main controller is electrically connected with the height sensor and the air suspension support air bag pressure sensor, and calculates the current actual load of the suspension according to signals transmitted by the air suspension support air bag pressure sensor; the vehicle further comprises a lateral acceleration sensor electrically connected with the main controller, and the lateral acceleration sensor is used for acquiring lateral acceleration signals of the vehicle.

3. The vehicle rollover prevention control system according to claim 1, wherein: the brake system is a compressed air electronic brake system, the compressed air electronic brake system comprises an electric control unit, a brake air chamber regulator, an air pressure joint, a brake and a brake air storage cylinder, the electric control unit and the brake air chamber regulator are electrically connected with a main controller, and the main controller performs closed-loop regulation on the brake pressure of the controller according to a brake request electric signal of a CAN bus or an air pressure signal of the brake request air pressure joint; the electric control unit and the brake air chamber regulator are integrated on the main controller, the brake system further comprises a rear axle EBS regulator electrically connected with the main controller, and the main controller implements closed-loop regulation on the service brake of the rear axle double-cavity brake through the rear axle EBS regulator.

4. A vehicle rollover prevention control method applied to the vehicle rollover prevention control system according to any one of claims 1 to 3, characterized in that: comprises the following steps of (a) preparing a solution,

s1, acquiring fixed parameters of a vehicle;

s3, obtaining dynamic parameters of the vehicle, comparing the dynamic parameters with the static parameters in the step S2 to obtain dynamic characteristic quantity, wherein the dynamic characteristic quantity is the difference of the dynamic signals deviating from the static parameters;

s5, calculating a current rollover trend characteristic quantity K according to the dynamic characteristic quantities and the current weighting coefficients of the dynamic characteristic quantities;

the suspension system is an air suspension system, the air suspension system comprises an air suspension air bag, an air suspension electric control valve and an air suspension air storage cylinder, the air suspension electric control valve is used for adjusting the pressure of the air supporting air bag, the suspension load acquisition module comprises an air suspension supporting air bag pressure sensor used for detecting the pressure of the air suspension air bag, and the main controller is electrically connected with the air suspension supporting air bag pressure sensor and the air suspension electric control valve to acquire the state of the air suspension and control the air suspension electric control valve; the vehicle body inclination acquisition module is a suspension height sensor, the wheel speed acquisition module is a wheel speed sensor, and the lateral acceleration acquisition module is a lateral acceleration sensor; the static parameters of the vehicle comprise air suspension static height, air suspension support air bag air pressure, lateral acceleration and wheel speed, dynamic characteristic quantities obtained in the step S3 are respectively defined as Ka for lateral acceleration, kh for air suspension height, kp for air suspension support air bag pressure and Kv for wheel speed, dynamic weighting coefficients of the dynamic characteristic quantities in the step S4 are defined as Wa for lateral acceleration, wh for air suspension height, wp for air suspension support air bag pressure, wv for wheel speed, and K for rollover trend in the step S5:

5. the vehicle rollover prevention control method according to claim 4, characterized in that: the fixed parameters of the vehicle are parameters having an influence on the rollover, and the fixed parameters of the vehicle are solidified in software of a main controller of the vehicle or in a calibration file written into the main controller.

6. The vehicle rollover prevention control method according to claim 4, characterized in that: defining a suspension adjustment threshold value of K ₁ When the rollover trend characteristic quantity K exceeds the suspension regulation threshold value K ₁ The main controller implements air suspension height adjustment through an air suspension electric control valve: pressurizing the outer suspension support airbag and depressurizing the inner suspension support airbag; defining a driver warning threshold as K ₂ When the rollover trend characteristic quantity K exceeds the suspension regulation threshold value K ₂ If the alarm is not detected, the main controller controls the alarm device to give an alarm; defining an active braking intervention threshold value as K ₃ When the rollover trend characteristic quantity K exceeds the suspension regulation threshold value K ₃ The main controller controls the brake to apply the braking operation; defining a rollover unavoidable alarm threshold K ₄ When the rollover trend characteristic quantity K exceeds the suspension regulation threshold value K ₄ And the main controller gives an alarm by controlling the alarm device.