Anti-rollover control method and control system for emergency vehicle used for rescue

Abstract

The present invention relates to an anti-rollover control method for an emergency vehicle for rescue and a control system thereof, which comprises the following steps: S1, constructing an anti-rollover control system for an emergency vehicle; S2, calculating a non-tripping rollover index RI of an emergency vehicle traveling on a structured road; S3, predicting a whole vehicle rollover index PRI of an emergency vehicle traveling on a complex road; S4, judging whether the rollover index of the emergency vehicle exceeds a threshold. The present invention adopts two forms of rollover indexes, namely, a tripping rollover and a non-tripping rollover. According to the characteristics of different rollover forms, the vehicle rollover can be effectively prevented by controlling the action of the actuator in the active suspension. At the same time, the active suspension of the front axle obtains complex road surface excitation information, which can predict the actuating force of the actuator of the active suspension on the rear axle of the emergency vehicle in advance, and can effectively alleviate the impact of the road surface excitation on the rear axle wheel, thereby reducing the influence of the road surface excitation on the vehicle rollover, so as to improve the safety of the emergency rescue vehicle.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle control, and in particular relates to an anti-rollover control method of an emergency vehicle for rescue and a control system thereof. Background Art

[0002] my country's land terrain and road conditions are complex and diverse. Multi-axle heavy-load emergency rescue vehicles, as the main equipment for land rescue, often have rollover accidents during emergency rescue, especially when driving on damaged unstructured roads, which greatly delays the rescue time and reduces the rescue efficiency. Therefore, it is urgent to take necessary protective measures to protect the safety of rescue workers and improve rescue efficiency.

[0003] There are many reasons for vehicle rollover, which are mainly divided into two forms: trip-type rollover and non-trip-type rollover. For example, Chinese patent CN202010133753.5 discloses a control method for active tilting of vehicle rollover prevention, but it is only applicable to non-trip-type rollover and cannot perceive road surface information; for example, Chinese patent CN201910314744.3 discloses a rollover warning method considering changes in road surface parameters. This method is applicable to both forms of rollover, but only considers the information of the whole vehicle under road surface excitation, and does not consider the different effects of road surface excitation on the front and rear axle wheels of the vehicle. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides an anti-rollover control method and a control system for an emergency vehicle for rescue, which takes into account the influence of the vehicle's driving road environment on rollover, and infers the rollover index of the entire vehicle under road excitation by acquiring sensor data of the front axle of the emergency vehicle. When the rollover index exceeds a threshold, the actuator of the active suspension is driven to operate, so as to improve the safety of the emergency rescue vehicle.

[0005] The technical solution adopted by the present invention is a rollover prevention control method for an emergency vehicle for rescue, which comprises the following steps:

[0006] S1. Construct an anti-rollover control system for emergency vehicles;

[0007] S2, obtaining acceleration information of the emergency vehicle during driving based on a vehicle information collection unit, and calculating a non-tripping rollover index RI of the emergency vehicle driving on a structured road;

[0008] S3, using the front axle longitudinal half-vehicle rollover model to predict the vehicle rollover index PRI of the emergency vehicle traveling on a complex road, specifically comprising the following steps:

[0009] S31. Based on the front axle longitudinal half-vehicle rollover model, the sprung mass roll motion equation and the sprung mass vertical motion equation are established. The sprung mass roll motion equation is expressed as:

[0010]

[0011] Among them, I x is the moment of inertia of the sprung mass about the roll center, F 1 and F 2 are the vertical forces on the left and right sides of the active suspension, is the front axle body roll acceleration, and and are the vertical accelerations on both sides of the front axle vehicle body under road excitation;

[0012] The vertical motion equation of the sprung mass is expressed as:

[0013]

[0014] in, is the vertical acceleration of the front axle sprung mass;

[0015] S32, based on the front axle longitudinal half vehicle rollover model, establish the unsprung mass vertical motion equation, the unsprung mass vertical motion equation expression is:

[0016]

[0017]

[0018]

[0019] Among them, m u1 and m u2 are the unsprung masses on the left and right sides of the front axle, respectively, and m u1 =m u2 =m u , and are the vertical accelerations of the front left wheel and the front right wheel, respectively, and F t1 and F t2 are the vertical forces of the front left wheel and the front right wheel respectively;

[0020] S33, combining the expressions in step S31 and step S32, establishing the front axle longitudinal half-vehicle rollover model of the emergency vehicle, then the front axle longitudinal half-vehicle rollover index expression of the emergency vehicle is:

[0021]

[0022] Where m = m b +2m u , m u is the unsprung mass on the left or right side of the front axle; mb is the front axle sprung mass; are the vertical accelerations on both sides of the front axle under road excitation; l is the distance between the sensors on both sides of the front axle body;

[0023] S34, calculating the vehicle rollover index PRI of the emergency vehicle, the vehicle rollover index PRI of the emergency vehicle is expressed as:

[0024] PRI=K*R

[0025] Where K is the rollover factor;

[0026] S4. Determine whether the rollover index of the emergency vehicle exceeds a threshold value. If the non-tripping rollover index RI of the emergency vehicle is greater than 0.8, the active suspension anti-rollover control unit drives the actuator of the active suspension to operate; if the non-tripping rollover index RI of the emergency vehicle is less than or equal to 0.8 and the whole vehicle rollover index PRI of the emergency vehicle is greater than or equal to 0.8, the active suspension anti-rollover control unit drives the actuator of the active suspension to operate; if the whole vehicle rollover index of the emergency vehicle is less than or equal to 0.8, the active suspension anti-rollover control unit does not drive the actuator of the active suspension to operate.

[0027] Further, in step S4, when the non-tripping rollover index RI of the emergency vehicle is greater than 0.8, the emergency vehicle rolls over, and the reason for the rollover of the emergency vehicle is that the lateral acceleration is too large during emergency turning or emergency obstacle avoidance. The active suspension anti-rollover control unit can adjust the body roll angle of the emergency vehicle through the action of the actuator in the active suspension by acquiring sensor information at the center of mass of the emergency vehicle, so as to achieve the stable restoration of the body of the emergency vehicle and prevent the vehicle from rolling over; when the non-tripping rollover index RI of the emergency vehicle is less than or equal to 0.8 and the vehicle rollover index PRI of the emergency vehicle is greater than 0.8, the emergency vehicle rolls over, and the driving condition of the emergency vehicle is steering or straight driving under complex road excitation. The active suspension anti-rollover control unit pre-calculates the actuating force of the actuator of the active suspension on the rear axle of the emergency vehicle according to the wheel and body information parameters of the front axle of the emergency vehicle under complex road excitation, and can achieve the stable restoration of the body of the emergency vehicle and prevent the vehicle from rolling over by reducing the impact of road excitation on the rear axle wheels of the emergency vehicle.

[0028] Another aspect of the present invention provides a control system for the above-mentioned emergency vehicle rollover prevention control method for rescue, which includes a vehicle information collection unit, a vehicle rollover index calculation unit, an anti-rollover decision unit and an active suspension anti-rollover control unit, wherein the vehicle information collection unit includes an accelerometer and a body roll angle sensor, wherein the accelerometers are symmetrically arranged on both sides of the front end of the emergency vehicle body and the axle of the front wheel, and the body roll angle sensor is arranged at the center of mass of the emergency vehicle; the vehicle information collection unit, the vehicle rollover index calculation unit, the anti-rollover decision unit and the active suspension anti-rollover control unit are all connected to the main control unit of the emergency vehicle in communication, and the vehicle information collection unit includes an accelerometer and a body roll angle sensor, wherein the accelerometers are symmetrically arranged on both sides of the front end of the emergency vehicle body and the axle of the front wheel, and the body roll angle sensor is arranged at the center of mass of the emergency vehicle. The unit can collect and obtain the vehicle steering information, the acceleration information of the vehicle body and the front wheels during the driving of the emergency vehicle, the vehicle rollover index calculation unit can calculate the non-stumbling rollover index of the emergency vehicle in real time according to the acceleration information collected by the vehicle information collection unit, and infer the whole vehicle stumbling rollover index of the emergency vehicle, and the anti-rollover decision unit can compare the rollover index calculated in the vehicle rollover index calculation unit with the threshold of the emergency vehicle and feed back the decision result to the main control unit, and the main control unit controls the action of the actuator in the active suspension of the emergency vehicle through the active suspension anti-rollover control unit to realize the anti-rollover control of the emergency vehicle.

[0029] The characteristics and beneficial effects of the present invention are:

[0030] 1. The present invention provides an anti-rollover control method and control system for an emergency vehicle for rescue, which adopts two types of rollover indexes: stumbling type rollover and non-stumbling type rollover, and can accurately judge the rollover form of the vehicle. In addition, according to the characteristics of different rollover forms, the active suspension anti-rollover control unit controls the action of the actuator in the active suspension, which can effectively prevent the vehicle from rolling over.

[0031] 2. The present invention provides an anti-rollover control method and control system for an emergency vehicle for rescue. The front axle active suspension obtains road information and can calculate in advance the actuating force of the actuator of the active suspension on the rear axle of the emergency vehicle. Therefore, when the rear axle wheels are excited by the road surface, they can also be affected by the driving force of the actuator on the active suspension, which can effectively alleviate the impact of the road surface excitation on the rear axle wheels, thereby reducing the influence of the road surface excitation on the vehicle rollover.

[0032] 3. The present invention provides an anti-rollover control method and control system for an emergency vehicle for rescue, which use front axle wheels and vehicle body acceleration sensors to sense road information, analyze the impact of road excitation on vehicle rollover, and improve the accuracy and speed of rollover identification. Therefore, the control system of the present invention is simple and reliable, has good real-time performance, and fast control response. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a non-stumbling rollover dynamics model of the present invention;

[0034] Figure 2 is a schematic diagram of the front axle half vehicle rollover dynamics model of the present invention;

[0035] Figure 3 It is a flow chart of the anti-rollover control method of the emergency vehicle for rescue of the present invention;

[0036] Figure 4 is a front view of the sensor installation arrangement of the present invention;

[0037] Figure 5 It is a top view of the sensor installation arrangement of the present invention. DETAILED DESCRIPTION

[0038] In order to fully describe the technical content, structural features, objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

[0039] The present invention provides a method for preventing rollover of an emergency vehicle for rescue, such as Figure 1 to Figure 3 As shown, it includes the following steps:

[0040] S1. Construct an anti-rollover control system for emergency vehicles;

[0041] S2. Based on the vehicle information collection unit, the acceleration information of the emergency vehicle during driving is obtained, and the non-tripping rollover index RI of the emergency vehicle driving on the structured road is calculated, as follows:

[0042] like Figure 1 As shown in FIG. 1 , for non-tripping rollover, a rollover evaluation index based on the vehicle lateral load transfer rate LTR is first established, that is, the vehicle lateral load transfer rate LTR is used as the rollover evaluation index RI, and the rollover evaluation index / load transfer rate is defined as:

[0043]

[0044] Among them, F zl and F zr They are the vertical loads of the left wheel and the right wheel respectively. When LTR>1 or LTR<-1, the single wheel of the vehicle leaves the ground, and the vehicle is considered to have rolled over.

[0045] However, due to the vertical force F zl and F zr It is difficult to measure, so F is calculated based on the non-tripping rollover model. zl -F zr , whose expression is:

[0046]

[0047] F zl +F zr =mg (3)

[0048] Substituting (2) and (3) into (1), we can obtain:

[0049]

[0050] Among them, m is the vehicle mass, m s is the sprung mass of the vehicle, a y is the lateral acceleration of the vehicle, is the roll angle of the vehicle, B is the wheelbase between the front left wheel and the front right wheel; h is the vertical distance from the center of mass of the sprung mass of the vehicle to the roll center.

[0051] S3, using the front axle longitudinal half-vehicle rollover model, predict the vehicle rollover index PRI of the emergency vehicle driving on complex roads, such as Figure 4 As shown, the specific steps include:

[0052] S31. Based on the front axle longitudinal half-vehicle rollover model, the sprung mass roll motion equation and the sprung mass vertical motion equation are established. The sprung mass roll motion equation is expressed as:

[0053]

[0054] Among them, I x is the moment of inertia of the sprung mass about the roll center, F 1 and F 2 are the vertical forces on the left and right sides of the active suspension, is the front axle body roll acceleration, and and They are the vertical accelerations on both sides of the front axle vehicle body under road excitation, among which the sprung mass is the mass of the vehicle supported by the suspension (that is, the total mass of all components above the suspension), which is called the sprung mass.

[0055] The vertical motion equation of the sprung mass is expressed as:

[0056]

[0057] Among them, m s is the sprung mass of the vehicle, is the vertical acceleration of the front axle sprung mass.

[0058] S32. Based on the front axle longitudinal half-vehicle rollover model, the vertical motion equation of the unsprung mass is established, and the expression of the vertical motion equation of the unsprung mass is:

[0059]

[0060]

[0061]

[0062] Among them, m u1 and m u2 are the unsprung masses on the left and right sides of the front axle, respectively, and m u1 =m u2 =m u , and are the vertical accelerations of the front left wheel and the front right wheel, respectively, and F t1 and F t2 They are the vertical forces of the front left wheel and the front right wheel respectively.

[0063] S33, combining the expressions in step S31 and step S32, establishing the front axle longitudinal half-vehicle rollover model of the emergency vehicle, then the front axle longitudinal half-vehicle rollover index expression of the emergency vehicle is:

[0064]

[0065] Where m = m b +2m u , m u is the unsprung mass on the left or right side of the front axle; m b is the front axle sprung mass; are the vertical accelerations on both sides of the front axle vehicle body under road excitation; l is the distance between the sensors on both sides of the front axle vehicle body.

[0066] S34. Calculate the whole vehicle rollover index PRI of the emergency vehicle. Considering the characteristics of the emergency vehicle, such as heavy load, long body, rearward center of gravity, and the influence of active suspension torsion performance on rollover performance, the vehicle is divided into front and rear parts. The whole vehicle rollover index is estimated in real time by multiplying the rollover factor with the rollover index of the front axle half vehicle. The expression of the whole vehicle rollover index PRI of the emergency vehicle is:

[0067] PRI=K*R (11)

[0068] Where K is the rollover factor.

[0069] S4. Determine whether the rollover index of the emergency vehicle exceeds the threshold. If the non-tripping rollover index RI of the emergency vehicle is greater than 0.8, the active suspension anti-rollover control unit drives the actuator of the active suspension to operate; if the non-tripping rollover index RI of the emergency vehicle is less than or equal to 0.8 and the whole vehicle rollover index PRI of the emergency vehicle is greater than or equal to 0.8, the active suspension anti-rollover control unit drives the actuator of the active suspension to operate; if the whole vehicle rollover index of the emergency vehicle is less than or equal to 0.8, the active suspension anti-rollover control unit does not drive the actuator of the active suspension to operate.

[0070] Further, in step S4, when the non-tripping rollover index RI of the emergency vehicle is greater than 0.8, the emergency vehicle rolls over, and the reason for the rollover of the emergency vehicle is that the lateral acceleration of the vehicle is too large during emergency turning or emergency obstacle avoidance, the active suspension anti-rollover control unit can adjust the body roll angle of the emergency vehicle through the action of the actuator in the active suspension by obtaining sensor information at the center of mass of the emergency vehicle, so as to realize the restoration of the body of the emergency vehicle to be stable and prevent the vehicle from rolling over;

[0071] When the non-tripping rollover index RI of the emergency vehicle is ≤0.8 and the vehicle rollover index PRI of the emergency vehicle is >0.8, the emergency vehicle rolls over. The driving condition of the emergency vehicle is turning or straight driving under complex road excitation. The active suspension anti-rollover control unit pre-calculates the actuating force of the actuator of the active suspension on the rear axle of the emergency vehicle according to the wheel and body information parameters of the front axle of the emergency vehicle under complex road excitation, that is, the rear axle active suspension pre-calculates the actuator driving force according to the road information obtained by the front axle active suspension. Therefore, when the rear axle wheels are excited by the road surface, they can be affected by the driving force of the active suspension actuator at the same time, which can reduce the impact of the road surface excitation on the rear axle wheels of the emergency vehicle, and can achieve the stable restoration of the emergency vehicle body to prevent the vehicle from rolling over.

[0072] When the vehicle rollover index PRI of the emergency vehicle is ≤0.8, the active suspension anti-rollover control unit does not work and the active suspension returns to the control mode of adjusting the vehicle's driving smoothness.

[0073] Another aspect of the present invention provides a control system for an emergency vehicle rollover prevention control method for rescue, such as Figure 4 and Figure 5 As shown, it includes a vehicle information collection unit, a vehicle rollover index calculation unit, an anti-rollover decision unit and an active suspension anti-rollover control unit. The vehicle information collection unit includes an accelerometer 1 and a body roll angle sensor 2. The accelerometers 1 are symmetrically arranged on both sides of the front end of the emergency vehicle body and the axle of the front wheel, and the body roll angle sensor 2 is arranged at the center of mass of the emergency vehicle.

[0074] In a preferred embodiment, the vehicle information collection unit, the vehicle rollover index calculation unit, the anti-rollover decision unit and the active suspension anti-rollover control unit are all communicatively connected to the main control unit of the emergency vehicle, and the vehicle information collection unit can collect and obtain the vehicle steering information, the acceleration information of the vehicle body and the front wheels during the driving of the emergency vehicle, the vehicle rollover index calculation unit can calculate the non-stumbling type rollover index of the emergency vehicle in real time according to the acceleration information collected by the vehicle information collection unit and infer the whole vehicle stumbling type rollover index of the emergency vehicle, and the anti-rollover decision unit can compare the rollover index calculated in the vehicle rollover index calculation unit with the threshold of the emergency vehicle and feed back the decision result to the main control unit, and the main control unit controls the actuator action of the active suspension in the emergency vehicle through the active suspension anti-rollover control unit to realize the anti-rollover control of the emergency vehicle.

[0075] The embodiments described above are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A rollover prevention control method for an emergency vehicle for rescue, It is characterized in that It includes the following steps: S1. Construct an anti-rollover control system for emergency vehicles; S2, obtaining acceleration information of the emergency vehicle during driving based on a vehicle information collection unit, and calculating a non-tripping rollover index RI of the emergency vehicle driving on a structured road; S3, using the front axle longitudinal half-vehicle rollover model to predict the vehicle rollover index PRI of the emergency vehicle traveling on a complex road, specifically comprising the following steps: S31. Based on the front axle longitudinal half-vehicle rollover model, the sprung mass roll motion equation and the sprung mass vertical motion equation are established. The sprung mass roll motion equation is expressed as: Among them, I x is the moment of inertia of the sprung mass about the roll center, F 1 and F 2 are the vertical forces on the left and right sides of the active suspension, is the front axle body roll acceleration, and and are the vertical accelerations on both sides of the front axle vehicle body under road excitation, m is the vehicle mass, m s is the sprung mass of the vehicle, a y is the lateral acceleration of the vehicle, is the roll angle of the vehicle, B is the wheelbase between the front left wheel and the front right wheel; h is the vertical distance from the center of mass of the sprung mass of the vehicle to the roll center; The vertical motion equation of the sprung mass is expressed as: in, is the vertical acceleration of the front axle sprung mass; S32. Based on the front axle longitudinal half-vehicle rollover model, the vertical motion equation of the unsprung mass is established, and the expression of the vertical motion equation of the unsprung mass is: Among them, m u1 and m u2 are the unsprung masses on the left and right sides of the front axle, respectively, and m u1 =m u2 =m u , and are the vertical accelerations of the front left wheel and the front right wheel, respectively, and F t1 and F t2 are the vertical forces of the front left wheel and the front right wheel respectively; S33, combining the expressions in step S31 and step S32, establishing the front axle longitudinal half-vehicle rollover model of the emergency vehicle, then the front axle longitudinal half-vehicle rollover index expression of the emergency vehicle is: Where m = m b +2m u , m u is the unsprung mass on the left or right side of the front axle; m b is the front axle sprung mass; are the vertical accelerations on both sides of the front axle under road excitation; l is the distance between the sensors on both sides of the front axle body; S34, calculating the vehicle rollover index PRI of the emergency vehicle, the vehicle rollover index PRI of the emergency vehicle is expressed as: PRI=K*R Where K is the rollover factor; S4. Determine whether the rollover index of the emergency vehicle exceeds a threshold value. If the non-tripping rollover index RI of the emergency vehicle is greater than 0.8, the active suspension anti-rollover control unit drives the actuator of the active suspension to operate; if the non-tripping rollover index RI of the emergency vehicle is less than or equal to 0.8 and the whole vehicle rollover index PRI of the emergency vehicle is greater than or equal to 0.8, the active suspension anti-rollover control unit drives the actuator of the active suspension to operate; if the whole vehicle rollover index of the emergency vehicle is less than or equal to 0.8, the active suspension anti-rollover control unit does not drive the actuator of the active suspension to operate.

2. The anti-rollover control method for emergency vehicles used for rescue according to claim 1, It is characterized in that In step S4, when the non-tripping rollover index RI of the emergency vehicle is greater than 0.8, the emergency vehicle rolls over, and the reason for the rollover of the emergency vehicle is that the lateral acceleration of the vehicle is too large during emergency turning or emergency obstacle avoidance. The active suspension anti-rollover control unit can adjust the body roll angle of the emergency vehicle through the action of the actuator in the active suspension by acquiring the sensor information at the center of mass of the emergency vehicle, so as to achieve the stable restoration of the body of the emergency vehicle and prevent the vehicle from rolling over; when the non-tripping rollover index RI of the emergency vehicle is less than or equal to 0.8 and the vehicle rollover index PRI of the emergency vehicle is greater than 0.8, the emergency vehicle rolls over, and the driving condition of the emergency vehicle is steering or straight driving under complex road excitation. The active suspension anti-rollover control unit pre-calculates the actuating force of the actuator of the active suspension on the rear axle of the emergency vehicle according to the wheel and body information parameters of the front axle of the emergency vehicle under complex road excitation, and can achieve the stable restoration of the body of the emergency vehicle and prevent the vehicle from rolling over by reducing the impact of road excitation on the rear axle wheels of the emergency vehicle.

3. A control system for implementing the anti-rollover control method for emergency vehicles for rescue as claimed in claim 1 or 2, It is characterized in that It includes a vehicle information collection unit, a vehicle rollover index calculation unit, an anti-rollover decision unit and an active suspension anti-rollover control unit. The vehicle information collection unit includes an accelerometer and a body roll angle sensor. The accelerometers are symmetrically arranged on both sides of the front end of the emergency vehicle body and the axle of the front wheel, and the body roll angle sensor is arranged at the center of mass of the emergency vehicle. The vehicle information collection unit, the vehicle rollover index calculation unit, the anti-rollover decision unit and the active suspension anti-rollover control unit are all communicatively connected to the main control unit of the emergency vehicle, and the vehicle information collection unit can collect and obtain the vehicle steering information, the acceleration information of the vehicle body and the front wheels during the driving process of the emergency vehicle, the vehicle rollover index calculation unit can calculate the non-stumbling type rollover index of the emergency vehicle in real time according to the acceleration information collected by the vehicle information collection unit and infer the whole vehicle stumbling type rollover index of the emergency vehicle, and the anti-rollover decision unit can compare the rollover index calculated in the vehicle rollover index calculation unit with the threshold value of the emergency vehicle and feed back the decision result to the main control unit, and the main control unit controls the action of the actuator in the active suspension of the emergency vehicle through the active suspension anti-rollover control unit to realize the anti-rollover control of the emergency vehicle.

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