A hazardous chemical liquid tank truck roll-over prevention control method

Abstract

This invention discloses a method for preventing rollover of hazardous chemical tank trucks. The steps are as follows: transforming the tank's coordinate system; calculating the tank's center of gravity height when stationary; calculating the vertical lateral deviation height of the tank's center of gravity during swaying; calculating the overall tank's center of gravity offset height; and implementing rollover prevention control. This invention employs a rollover prevention control method based on center of gravity lateral deviation height compensation. The center of gravity height calculation method, through coordinate transformation, makes the formula applicable regardless of the amount of hazardous chemicals loaded in the tank. It can also accurately calculate the tank's center of gravity offset height at each moment, taking into account the transient changes in vehicle tilt. Furthermore, this rollover prevention control method is applicable to any mechanism capable of compensating for center of gravity lateral deviation height. The technical solution is simple, the measurement is more accurate, and the applicability and reliability are stronger, making it highly valuable for widespread application.

Description

Technical Field

[0001] This invention relates to vehicle dynamic control, and in particular to a method for preventing rollover of hazardous chemical tank trucks. Background Technology

[0002] Road transport, characterized by its large loading capacity and low cost, is currently the primary mode of transport for hazardous chemicals in my country. Among these, tank trucks carrying hazardous chemicals are specialized heavy-duty tank vehicles characterized by high load capacity, high center of gravity, and large size. During transport, when these tank trucks are not fully loaded and operate under complex conditions, the liquid inside the tank is prone to strong sloshing and interaction with the tank body. This causes a shift in the vehicle's center of gravity, resulting in drastic changes in axle load and increasing the risk of tilting or even overturning. This severely impacts the vehicle's safety and stability. Furthermore, the hazardous chemicals transported by these tank trucks are highly sensitive; if a rollover occurs during transport and causes a leak, it will not only result in significant economic losses and environmental pollution but also endanger the safety of nearby residents. Therefore, there is an urgent need for a rollover prevention control method with high center of gravity compensation to reduce the occurrence of rollover accidents. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a method for preventing the rollover of hazardous chemical tank trucks. This method monitors the height of the tank's center of gravity deviation during vehicle operation in real time and determines whether the vehicle is at risk of rollover. When the vehicle shows a tendency to rollover, the control system will control the suspension device, which can achieve height compensation, to actively control the tank truck body, promptly correct the worsening trend of vehicle tilt, protect the driver, prevent the vehicle from rolling over and damaging the tank, and thus improve the vehicle's safety and stability.

[0004] Technical solution: The present invention provides a method for preventing the rollover of hazardous chemical tank trucks, comprising the following steps:

[0005] (1) Transform the tank coordinate system;

[0006] A rectangular coordinate system yoz is established at the center of the axle. Position sensors are installed at the center of the axle and the center of the tank to measure the lateral deviation of the tank center relative to the axle center coordinate system along the y and z axes. and Determine the tilt angle when the tank shakes, establish the elliptical equation of the tank in the yoz coordinate system when the tank shakes, transform the coordinates of two points A(y′1,z′1) and B(y′2,z′2) monitored by the liquid level sensor in the y′o′z′ coordinate system to the yoz coordinate system, and establish the straight line equation of the liquid free surface.

[0007] (2) Find the height of the center of mass of the tank when it is at rest;

[0008] When the tanker truck is loaded with goods and the vehicle is stationary, the height of the center of mass of the tank's central section M in the z-axis direction is calculated using the ellipse equation determined in step (1) and the equation of the free liquid surface AB at this time.

[0009] (3) Calculate the vertical lateral deflection height of the tank's center of mass during the shaking;

[0010] While the tanker truck is in motion, select multiple cross-sections of equal length and calculate the vertical height of the centroid of each cross-section;

[0011] (4) Calculate the height of the entire tank's center of mass offset;

[0012] The average height of the center of mass of each cross section of the tank swaying obtained in step (3) is subtracted from the height of the stationary center of mass of the tank determined in step (2) to obtain the offset height of the center of mass of the entire tank.

[0013] (5) Anti-rollover control;

[0014] When the tank center of gravity offset height determined in step (4) is compared with a preset threshold, and the vehicle is at risk of rollover, the on-board ECU system controls the active suspension device that can achieve vehicle posture control to perform anti-rollover control.

[0015] The specific steps (1) are as follows:

[0016] A Cartesian coordinate system yoz is established at the center of the axle. Since the liquid level sensor is located inside the tank, it will shake with the tank, and the coordinate system will change accordingly during the shaking. Position sensors are placed at the center of the axle and the center of the tank to measure the lateral deviation of the tank center relative to the axle center coordinate system on the y and z axes. and The tilt angle at the center of the tank is:

[0017]

[0018] When the tank shakes, the equation of the ellipse of the tank on the coordinate system yoz is:

[0019]

[0020]

[0021] The liquid level sensor monitors the coordinates of two points, A(y′1,z′1) and B(y′2,z′2), in the y′o′z′ coordinate system. These coordinates are then transformed to represent them in the yoz coordinate system:

[0022]

[0023] Then in y′o′ zThe coordinates A(y′1,z′1) and B(y′2,z′2) obtained from monitoring in the coordinate system are transformed into A(y1,z1) and B(y2,z2). The free surface of the liquid is approximated as a straight line formed by the two points A(y1,z1) and B(y2,z2), and its equation is:

[0024]

[0025] In the formula, a and b are the minor axis and major axis of the elliptical tank, respectively.

[0026] Step (2) specifically involves:

[0027] When the tanker truck is loaded with goods and the vehicle is stationary, the straight line formed by A and B is:

[0028] z = z1

[0029] Then the height of the center of mass of the central section M in the z-axis direction when the vehicle is stationary can be calculated:

[0030]

[0031]

[0032]

[0033] In the formula, S M Let M be the cross-sectional area of ​​section M. Let M be the cross-sectional area moment of section M along the z-axis.

[0034] Step (3) specifically involves:

[0035] When the vehicle moves and causes swaying, calculate the height of the centroid of multiple selected sections of equal length, where a certain section D of the tank is... i The cross-sectional area of ​​the tank is:

[0036]

[0037] Section D i The cross-sectional area distance corresponding to the z-axis coordinate is:

[0038]

[0039] Then cross section D i The vertical height of the centroid is:

[0040]

[0041] Similarly, the vertical displacement heights z1, z2, z3, etc. of each section during tank swaying can be calculated.

[0042] In the formula, i = 1, 2, 3...

[0043] Step (4) specifically involves:

[0044] When n cross-sections of the tank are selected, calculate the vertical displacement height z of each cross-section during tank swaying. i The average value; i = 1, 2, 3…

[0045]

[0046] The height difference of the entire tank's center of gravity offset is:

[0047] z h =z p -z c .

[0048] Step (5) specifically involves:

[0049] Pre-set the centroid offset height threshold z k , z k The vertical offset height of the center of mass of the liquid inside the tank when the load on one side of the wheel is 0;

[0050] The tanker truck is equipped with an active suspension system capable of controlling the vehicle's attitude. In the event of a rollover hazard, the system raises the vehicle body to compensate for the lateral deviation height difference (z) of the vehicle's center of gravity, calculated through monitoring and interpretation. h ;

[0051] By monitoring the position of the liquid surface at a cross-section of the tank in real time and then calculating the centroid offset height, the vertical height z of the centroid sway at a certain cross-section of the liquid inside the tank is determined when the vehicle is subjected to road unevenness or turning. i Less than or equal to the set threshold z k If the vehicle is determined to be at risk of rollover, the vehicle control unit will control the vehicle to take emergency anti-rollover measures. The on-board ECU system first calculates the height difference of the tank body's center of gravity offset based on the sensor detection data, then calculates the active suspension control force output time based on the control force output characteristics of the active suspension that can achieve vehicle body attitude control, and finally performs anti-rollover control of the active suspension to achieve real-time adjustment of the control force of the left and right active control suspensions, thereby improving the lateral stability of the tank truck.

[0052] The upward acceleration during suspension rollover control is:

[0053]

[0054] F represents the control force that the active suspension can output; m c The empty weight of the tanker truck; m s The mass of liquid loaded into the tanker truck;

[0055] Time required for the suspension to adjust the vehicle body to a balanced position:

[0056]

[0057] A computer storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for preventing the rollover of a hazardous chemical tanker truck.

[0058] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned method for preventing the rollover of a hazardous chemical tanker truck.

[0059] Beneficial effects: Compared with the prior art, the present invention has the following advantages: The present invention adopts a rollover prevention control method with center of gravity lateral deviation height compensation. The center of gravity height calculation method adopted, through coordinate transformation, makes the calculation formula of center of gravity lateral deviation height applicable regardless of the amount of hazardous chemicals loaded in the tank. It can also accurately calculate the center of gravity offset height of the tank at each moment, taking into account the transient changes of vehicle body tilt. Moreover, the rollover prevention control method is applicable to all mechanisms and devices that can realize center of gravity lateral deviation height compensation. The technical solution is simple, the measurement is more accurate, the applicability and reliability are stronger, and it has good promotion and application value. Attached Figure Description

[0060] Figure 1 This is a schematic diagram illustrating the calculation of the center of gravity offset height of the liquid tanker truck according to the present invention;

[0061] Figure 2 This is a flowchart of the anti-rollover control process for liquid tank trucks according to the present invention. Detailed Implementation

[0062] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0063] A method for preventing the rollover of a hazardous chemical tanker truck includes the following steps:

[0064] (1) Transform the tank coordinate system;

[0065] A rectangular coordinate system yoz is established at the center of the axle. Position sensors are installed at the center of the axle and the center of the tank to measure the lateral deviation of the tank center relative to the axle center coordinate system along the y and z axes. and Determine the tilt angle when the tank shakes, establish the elliptical equation of the tank in the yoz coordinate system when the tank shakes, transform the coordinates of two points A(y′1,z′1) and B(y′2,z′2) monitored by the liquid level sensor in the y′o′z′ coordinate system to the yoz coordinate system, and establish the straight line equation of the liquid free surface.

[0066] (2) Find the height of the center of mass of the tank when it is at rest;

[0067] When the tanker truck is loaded with goods and the vehicle is stationary, the height of the center of mass of the tank's central section M in the z-axis direction is calculated using the ellipse equation determined in step (1) and the equation of the free liquid surface AB at this time.

[0068] (3) Calculate the vertical lateral deflection height of the tank's center of mass during the shaking;

[0069] While the tanker truck is in motion, select multiple cross-sections of equal length and calculate the vertical height of the centroid of each cross-section;

[0070] (4) Calculate the height of the entire tank's center of mass offset;

[0071] The average height of the center of mass of each cross section of the tank swaying obtained in step (3) is subtracted from the height of the stationary center of mass of the tank determined in step (2) to obtain the offset height of the center of mass of the entire tank.

[0072] (5) Anti-rollover control;

[0073] When the tank center of gravity offset height determined in step (4) is compared with a preset threshold, and the vehicle is at risk of rollover, the on-board ECU system controls the active suspension device that can achieve vehicle posture control to perform anti-rollover control.

[0074] The specific steps (1) are as follows:

[0075] A Cartesian coordinate system yoz is established at the center of the axle. Since the liquid level sensor is located inside the tank, it will shake with the tank, and the coordinate system will change accordingly during the shaking. Position sensors are placed at the center of the axle and the center of the tank to measure the lateral deviation of the tank center relative to the axle center coordinate system on the y and z axes. and The tilt angle at the center of the tank is:

[0076]

[0077] When the tank shakes, the equation of the ellipse of the tank on the coordinate system yoz is:

[0078]

[0079]

[0080] Liquid level sensor at y′o′ z The coordinates of points A(y′1,z′1) and B(y′2,z′2) are monitored in the y′ coordinate system. These coordinates are then transformed to represent them in the yoz coordinate system:

[0081]

[0082] Then, A(y′1,z′1) and B(y′2,z′2) obtained in the y′o′z′ coordinate system are transformed into A(y1,z1) and B(y2,z2). The free surface of the liquid can be approximated as a straight line formed by the two points A(y1,z1) and B(y2,z2), and its equation is:

[0083]

[0084] In the formula, a and b are the minor axis and major axis of the elliptical tank, respectively.

[0085] Step (2) specifically involves:

[0086] When the tanker truck is loaded with goods and the vehicle is stationary, the straight line formed by A and B is:

[0087] z = z1

[0088] Then the height of the center of mass of the central section M in the z-axis direction when the vehicle is stationary can be calculated:

[0089]

[0090]

[0091]

[0092] In the formula, S M Let M be the cross-sectional area of ​​section M. Let M be the cross-sectional area moment of section M along the z-axis.

[0093] Step (3) specifically involves:

[0094] When the vehicle moves and causes swaying, calculate the height of the centroid of multiple selected sections of equal length, where a certain section D of the tank is... i The cross-sectional area of ​​the tank is:

[0095]

[0096] Section D i The cross-sectional area distance corresponding to the z-axis coordinate is:

[0097]

[0098] Then cross section D i The vertical height of the centroid is:

[0099]

[0100] Similarly, the vertical displacement heights z1, z2, z3, etc. of each section during tank swaying can be calculated.

[0101] In the formula, i = 1, 2, 3...

[0102] Step (4) specifically involves:

[0103] When n cross-sections of the tank are selected, calculate the vertical displacement height z of each cross-section during tank swaying. i The average value; i = 1, 2, 3…

[0104]

[0105] The height difference of the entire tank's center of gravity offset is:

[0106] z h =z p -z c .

[0107] Step (5) specifically involves:

[0108] Pre-set the centroid offset height threshold z k , z k The vertical offset height of the center of mass of the liquid inside the tank when the load on one side of the wheel is 0;

[0109] The tanker truck is equipped with an active suspension system capable of controlling the vehicle's attitude. In the event of a rollover hazard, the system raises the vehicle body to compensate for the lateral deviation height difference (z) of the vehicle's center of gravity, calculated through monitoring and interpretation. h ;

[0110] By monitoring the position of the liquid surface at a cross-section of the tank in real time and then calculating the centroid offset height, the vertical height z of the centroid sway at a certain cross-section of the liquid inside the tank is determined when the vehicle is subjected to road unevenness or turning. i Less than or equal to the set threshold z k If the vehicle is determined to be at risk of rollover, the vehicle control unit will control the vehicle to take emergency anti-rollover measures. The on-board ECU system first calculates the height difference of the tank body's center of gravity offset based on the sensor detection data, then calculates the active suspension control force output time based on the control force output characteristics of the active suspension that can achieve vehicle body attitude control, and finally performs anti-rollover control of the active suspension to achieve real-time adjustment of the control force of the left and right active control suspensions, thereby improving the lateral stability of the tank truck.

[0111] The upward acceleration during suspension rollover control is:

[0112]

[0113] F represents the control force that the active suspension can output; m c The empty weight of the tanker truck; m s The mass of liquid loaded into the tanker truck;

[0114] Time required for the suspension to adjust the vehicle body to a balanced position:

[0115]

[0116] like Figure 1 , 2 As shown, this invention involves installing liquid level sensors on equidistant cross-sections of the tank to monitor the intersection points A(y1,z1) and B(y2,z2) of the liquid surface and the tank. The vertical height of the centroid offset at points A and B is inferred. Similarly, the vertical offset height of the centroid at another selected cross-section is calculated and compared with a pre-set centroid tilt angle threshold z. k In contrast, when the vertical height z of the centroid of a certain cross section i ≤z k At this time, the vehicle control unit controls the vehicle to enter the emergency rollover prevention control state.

[0117] In this embodiment, as Figure 2 As shown, after the tanker truck is loaded with hazardous chemicals, the liquid level sensor monitors the liquid level in the tank. The onboard ECU calculates the center of mass of the liquid in the tanker truck when it is stationary by using the tank monitoring unit to monitor the liquid level in multiple sections of the tanker truck in real time. During the transport of the tanker truck, the monitoring unit monitors the surface condition of the liquid level at multiple sections of the tanker truck in real time and transmits the monitoring data to the onboard ECU. The onboard ECU calculates the vertical lateral deviation height of the center of mass and compares it with a preset threshold z. k In contrast, when the vertical height of the centroid of all cross-sections is not less than z k When the suspension maintains normal operating mode, and the vertical height z of the center of gravity of a certain section is... i ≤z k In such cases, the vehicle's ECU will issue a rollover warning to the driver's cab, reminding them to slow down or stop. It will also control the active suspension, which compensates for the vehicle's center of gravity height, to perform anti-rollover control and identify... The angle of the rollover angle determines the direction of the tanker truck's rollover. The onboard ECU then transmits a control signal to the active suspension system in the rollover direction. The active suspension system's control mechanism receives this control and provides an upward thrust to the tanker truck's body in the rollover direction. The time required to correct the vehicle's lateral center of gravity.

Claims

1. A hazardous chemical liquid tank truck roll-over prevention control method, characterized by, The method comprises the following steps: (1) transforming the tank coordinate system; A rectangular coordinate system yoz is established at the center of the axle, and a position sensor is arranged at the center of the axle and the center of the tank to measure the side slip amount of the center of the tank relative to the center of the axle coordinate system in the y axis and the z axis and , determine the roll angle when the tank is swaying, establish the elliptical equation of the tank when the tank is swaying on the coordinate system yoz, monitor the coordinates of two points and and in the coordinate system by the liquid level sensor, change to the coordinate system, and establish the straight line equation of the liquid free surface; (2) calculating the height of the tank center of mass in the z-axis direction when the vehicle is in a static state; (3) calculating the height of the tank center of mass in the z-axis direction when the vehicle is in a static state; (4) calculating the height of the tank center of mass in the z-axis direction when the vehicle is in a static state; (5) preventing the vehicle from rolling over; When the vehicle motion produces a sway, the selected multiple equal-length cross-section centroid heights are calculated, wherein the cross-sectional area of the tank body at a certain cross-section of the tank body is: ； cross section The cross-sectional area moment corresponding to the z-axis coordinate is: ； the centroid vertical height of the section is ； Similarly, the vertical displacement of each cross section of the tank body when the tank body is shaken can be calculated , , … In the formulae, ; The step (1) is specifically: When the tank is in a static state, the straight line formed by the A and B points is: The step (2) is specifically: When the tank is in a static state, the straight line formed by the A and B points is:

2. The roll-over prevention control method for a hazardous article liquid tank truck according to claim 1, characterized by, The step (4) is specifically: A rectangular coordinate system yoz is established at the center of the axle. Since the liquid level sensor is arranged inside the tank body, it will sway with the tank body, and the coordinate system will also change during the swaying process. A position sensor is arranged at the center of the tank body and at the center of the axle to measure the side deviation of the center of the tank body relative to the coordinate system at the center of the axle in the y-axis and the z-axis and The roll angle of the center of the tank body is ； The step (5) is specifically: ； ； The liquid level sensor is in The two points are monitored in the coordinate system And The coordinates of the two points are changed to the coordinate system The two points are represented on the coordinate system ； Then in The monitoring of the obtained And Change into And The liquid free surface is approximately considered , The straight line equation of the two points is: ； In the formula, , are the short axis and the long axis of the elliptical tank body, respectively.

3. The roll-over prevention control method for a hazardous article liquid tank truck according to claim 1, characterized by, The step (5) is specifically: The step (5) is specifically: ； The computer program is executed by the processor to implement the method for preventing the hazardous chemical liquid tank truck from rolling over according to any one of claims 1-5. ； ； ； wherein is the cross-sectional area of the section M, is the section modulus of the section M in the z-axis.

4. The roll-over prevention control method for a hazardous article liquid tank truck according to claim 1, characterized by, The processor executes the computer program to implement the method for preventing the hazardous chemical liquid tank truck from rolling over according to any one of claims 1-5. When the cross section of the tank body is selected as n, the average value of the height of the vertical displacement of each cross section when the tank body is shaken is calculated ; ; ； ​ ； ； wherein is the cross-sectional area of the center section M when the vehicle is stationary, is the cross-sectional area moment of inertia of the section M about the z-axis.

5. The hazardous chemical liquid tank truck roll-over prevention control method according to claim 1, wherein ​ Setting a centroid offset height threshold in advance , is the vertical offset height of the liquid centroid in the tank when the load of one side wheel is 0. The liquid tank truck is provided with an active suspension device capable of realizing vehicle body posture control, and when the liquid tank truck is in danger of rollover, the vehicle body is lifted upward to support the vehicle body, and the lateral deviation height difference of the vehicle body mass center obtained through monitoring and calculation is compensated ; By monitoring the liquid surface position of the tank cross section in real time, then calculating the centroid offset height, when the vehicle is excited by the road surface or turns, the centroid of a certain cross section of the liquid in the tank shakes vertically Less than or equal to the set threshold At this time, it is determined that the vehicle is in danger of rollover, and the vehicle control unit will control the vehicle to take emergency anti-rollover measures. The vehicle-mounted ECU system first calculates the centroid offset height difference according to the sensor detection data, then calculates the active suspension control force output time according to the control force output characteristics of the active suspension capable of realizing vehicle body posture control, and finally performs anti-rollover control of the active suspension to realize real-time adjustment of the control force of the left and right active control suspensions and improve the roll stability of the liquid tank truck. ​ ； control force that can be output for the active suspension; empty mass of the tank truck body; loaded liquid mass of the tank truck; ​ ； wherein, h is the height of the center of mass of the tank when at rest in the z-axis; When the cross section of the tank body is selected as n, the average value of the height of the vertical displacement of each cross section when the tank body is shaken is calculated . ; 。 6. A computer storage medium having stored thereon a computer program, characterized in that ​ 7. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, ​

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