Transport vehicle anti-rollover control system and method based on micro-pressure gradient sensing and movable balance weight

Abstract

The invention provides a transport vehicle anti-rollover control system and method based on micro-pressure gradient sensing and a movable balance weight, and belongs to the technical field of transport vehicle anti-rollover control. In order to solve the technical problems that an existing anti-rollover system does not have an active centroid correction and adjustment mechanism and is poor in dynamic stability and robustness, a plurality of micro-pressure sensing units are transversely arranged at the contact position of a bottom plate and a liquid tank container; a temperature and liquid level sensor for acquiring the temperature and liquid level information of a medium in the liquid tank is arranged on the liquid tank container; an inertial measurement unit for measuring the posture and the transverse acceleration of the vehicle is mounted on the liquid tank container or the frame of the transport vehicle; a fusion controller, a movable counterweight assembly, an actuator driving assembly and a power supply and intrinsic safety isolation unit are further arranged on a frame of the transport vehicle, a man-machine interaction and diagnosis unit is arranged in a cab of the transport vehicle, and all the unit assemblies are electrically connected with the fusion controller through wires. The method is applied to vehicle rollover prevention control.

Description

Technical Field

[0001] This invention provides a control system and method for preventing rollover of transport vehicles based on micro-pressure gradient sensing and moving counterweight, belonging to the field of anti-rollover control technology for transport vehicles. Background Technology

[0002] Tanker trucks (including but not limited to oil tankers, chemical transport trucks, and slurry / mixture transport trucks) are prone to free surface tilting and sloshing under typical operating conditions such as acceleration, braking, and turning. This leads to lateral load transfer and transient center of gravity shift, which couples with the vehicle's lateral acceleration, roll posture, and tire lateral forces, increasing the risk of rollover. Once such vehicles roll over, in addition to vehicle and cargo loss, there may be cascading risks such as leakage, explosion, or environmental pollution, making them a high-risk link in the road transport safety system. With the development of smart logistics and intelligent driving / assisted driving technologies, transport vehicles have higher requirements for stability and interpretability in active safety, necessitating the development of an active rollover prevention control scheme that can operate stably under different loading rates, different media, and complex dynamic disturbances.

[0003] To prevent rollover accidents during transport, existing tank trucks typically use inertial measurement units (IMUs) to detect and estimate the lateral acceleration of the fluid inside the tank, triggering braking intervention based on empirical thresholds. However, IMUs lack robustness under conditions of installation stiffness, zero drift, and wave impact at different loading rates, and simple braking or torque limiting control cannot promptly change the vehicle's center of gravity position. Furthermore, existing baffle / compartment structures tend to passively suppress wave impact during longitudinal movement. For the risk of lateral rollover under turning lateral excitation, relying solely on passive sway suppression or braking intervention often fails to promptly offset the adverse effects of center of gravity shift, thus lacking an "active center of gravity correction" closed-loop control link. For the transport of special liquids such as rocket propellants, there are characteristics such as sensitivity to medium density and temperature, and complex containers. High-frequency pressure or attitude disturbances caused by liquid wave impact can easily lead to misjudgments, and changes in liquid level at different loading rates will reduce the stability of single-point estimation by the IMU. Traditional detection and control schemes cannot meet the requirements.

[0004] Therefore, there is an urgent need to develop a control system that directly estimates the lateral acceleration of a vehicle based on observations of the liquid pressure field and has the ability to actively correct and adjust the center of mass, in order to improve the rollover threshold, dynamic stability, and robustness to changes in the load rate of transport vehicles, and prevent lateral rollover accidents when the vehicle is turning. Summary of the Invention

[0005] In order to solve the technical problems existing in the background art, the present invention adopts the following technical solution: a transport vehicle anti-rollover control system based on micro-pressure gradient sensing and moving counterweight is provided, including a liquid tank container, the liquid tank container is fixed on the transport vehicle frame by a base plate, and multiple micro-pressure sensing units are arranged laterally at the position where the base plate contacts the liquid tank container.

[0006] Temperature and level sensors are also installed on the liquid tank container to obtain information on the temperature and level of the medium inside the tank.

[0007] An inertial measurement unit is installed on the liquid tank container or the frame of the transport vehicle to measure the vehicle's attitude and lateral acceleration.

[0008] The transport vehicle chassis is also equipped with a fusion controller, a moving counterweight assembly, an actuator drive assembly, and a power supply and intrinsically safe isolation unit. A human-machine interface and diagnostic unit is located in the driver's cab of the transport vehicle.

[0009] The movable counterweight assembly is arranged on the underside of the transport vehicle frame, and the actuator drive assembly is used to drive the movable counterweight assembly to move adaptively.

[0010] The human-machine interaction and diagnostic unit is electrically connected to the fusion controller via wires and is used to display alarm information, fault codes and record operating data;

[0011] The micro-pressure sensing unit, temperature and liquid level sensor, inertial measurement unit, and actuator drive assembly are all electrically connected to the fusion controller.

[0012] The power supply and intrinsic safety isolation unit supplies power to the micro-pressure sensing unit, temperature and liquid level sensor, inertial measurement unit, fusion controller, and actuator drive assembly, respectively, and achieves explosion-proof and intrinsic safety isolation.

[0013] The mobile counterweight assembly includes two guide rails fixed to the underside of the transport vehicle frame, a counterweight slide table that slides along the guide rails, and a counterweight block installed on the counterweight slide table. The counterweight slide table is connected to the actuator drive assembly via a ball screw motor or a linear motor.

[0014] Mechanical limit and buffer structures are provided at both ends of the guide rail's travel.

[0015] The counterweight slide is also equipped with a position sensor for detecting the current position of the counterweight block.

[0016] The actuator drive assembly includes a motor drive module and a brake control module. The motor drive module is used to drive a ball screw motor or a linear motor. The brake control module is used to control the moving counterweight assembly to stop moving when the system loses power or receives a fault signal, so that the counterweight block stops at its current position or returns to the center position of the guide rail.

[0017] The micro-pressure sensing unit is specifically a piezoresistive or capacitive MEMS micro-pressure sensor. A temperature compensation circuit is set inside the micro-pressure sensing unit, and an explosion-proof and corrosion-resistant structural housing is set outside.

[0018] At least three micro-pressure sensing units are installed along the vehicle's lateral x-axis at the contact point between the base plate and the liquid tank container to collect liquid pressure data at different lateral positions on the base plate.

[0019] The power supply and intrinsically safe isolation unit includes an on-board power interface, an explosion-proof safety barrier, and an isolated DC / DC converter unit, wherein:

[0020] The explosion-proof safety barrier is used to restrict the electrical energy and voltage entering the hazardous medium area, and the isolated DC / DC converter unit is used to provide isolated power to the micro-pressure sensing unit, temperature and liquid level sensor and inertial measurement unit.

[0021] The human-machine interaction and diagnostic unit includes a display screen, status indicator lights, and a communication interface. It can display lateral acceleration, the position of the counterweight, the system operating mode, and fault codes in real time. It can also connect to the vehicle network or external diagnostic equipment through the communication interface for data recording and remote upgrades.

[0022] The interior of the liquid tank container is also equipped with a flow guide baffle and a wave-reflecting cavity.

[0023] A method for preventing rollover of transport vehicles using a micro-pressure gradient sensing and moving counterweight-based anti-rollover control system includes the following control steps:

[0024] Step 1: During vehicle operation, multiple micro-pressure sensing units installed on the floor synchronously collect the bottom pressure values ​​at various lateral positions of the vehicle and record the position coordinates (x, y) of the corresponding measuring points in the vehicle coordinate system. i , z i ), where x i The position coordinates of the pressure-sensing unit (3) at the pressure-applying end opening in the vehicle coordinate system along the transverse x-axis are given by z. i Z represents the geometric height of the pressure-sensing terminal opening of the micro-pressure sensing unit. If all measuring points are at the same height, then z... i It is a constant;

[0025] Step 2: The filtering and regression calculation module inside the fusion controller performs low-pass filtering and / or Kalman filtering on the pressure signal collected by the micro-pressure sensing unit, and performs outlier removal and data processing within the sliding time window to obtain the pressure-position dataset for regression, expressed as:

[0026] , ;

[0027] in, The lower horizontal edge of the vehicle coordinate system Position coordinates along the axis The slope of the pressure-position relationship. For pressure, For the density of the liquid, For the pressure gradient, satisfying ;

[0028] Step 3: Within the sliding time window, the fusion controller establishes a pressure-position regression model based on the quasi-static linear assumption of the pressure field, expressed as:

[0029] ;

[0030] Where, p i Let x be the pressure value measured by the i-th micro-pressure sensing unit. i , z i ) represents the lateral coordinates and geometric height coordinates of the measuring point in the vehicle coordinate system, and N represents the number of measuring points;

[0031] The fusion controller uses the least squares method to estimate the parameters of the pressure-position regression model, and the calculation formula is as follows:

[0032] ;

[0033] Where c0 is a constant term in the regression model, representing the reference pressure level at the origin of the selected vehicle coordinate system, thus obtaining the lateral acceleration coefficient c1 and the vertical gravity acceleration coefficient c2.

[0034] Step 4: The fusion controller is based on the quasi-static form of the Euler momentum equation and combines the roll angle measured by the inertial measurement unit. The lateral acceleration coefficient c1 obtained in step three is converted into the initial value of the vehicle's lateral acceleration. The calculation formula is:

[0035] ;

[0036] in, Where is the density of the liquid; g is the acceleration due to gravity;

[0037] Step 5: If the compensated lateral acceleration of the vehicle exceeds the preset threshold of the fusion controller and continues for a set time, the fusion controller outputs a control command to the actuator drive component to drive the moving counterweight component to move so that the projection of the entire transport vehicle's center of gravity remains within the support area formed by the tire contact point.

[0038] In step two, before processing the pressure signal, outliers are removed from the pressure-position data using RANSAC or residual threshold methods, and a health index is constructed based on the regression residuals for online monitoring of the performance of the micro-pressure sensing unit.

[0039] The specific method for driving the moving counterweight component in step five is as follows:

[0040] When the compensated vehicle lateral acceleration When the value continuously exceeds the first threshold preset by the fusion controller, the fusion controller controls the counterweight slide to carry the counterweight block to move along the guide rail in the same direction as the calculated target displacement and the compensating lateral acceleration in the vehicle's lateral x-axis direction.

[0041] When the compensated vehicle lateral acceleration After the weight drops below the second threshold preset by the fusion controller and remains there for a set time, the fusion controller controls the counterweight slide to carry the counterweight block back to the safe position or the center position along the guide rail.

[0042] The advantages of this invention compared to existing technologies are as follows: The anti-rollover control system and method for transport vehicles based on micro-pressure gradient sensing and moving counterweight provided by this invention, by equidistantly arranging a micro-pressure sensor array along the lateral direction of the vehicle on the bottom plate of the liquid container, and integrating the controller based on the one-dimensional form of the Euler momentum equation, directly calculates the lateral acceleration of the vehicle using the liquid pressure field, which is insensitive to changes in vehicle load rate and installation conditions; when the calculated acceleration value exceeds a threshold, the counterweight under the vehicle is controlled to move so that the projection of the vehicle's center of gravity is maintained within the support area formed by the tire contact point (at least within the lateral support interval corresponding to the wheel track), thereby reducing the risk of rollover and improving the equivalent static rollover threshold and dynamic stability; in addition, this invention also uses filtering and attitude compensation to enhance robustness, and incorporates anti-anomaly regression, attitude / This invention combines density online compensation, anti-wave triggering, and displacement mapping technologies, unlike existing technologies that only intervene with counterweights or brakes at the execution end or are triggered solely by inertial measurement units. This effectively improves measurement accuracy and the effectiveness of compensation-linked control. Especially for high-risk media transportation scenarios such as fuel, hazardous chemicals, or propellants, this invention adopts a closed-loop link of "pressure field observation - lateral acceleration reconstruction - active counterweight compensation," which makes vehicle stability control no longer dependent on a single inertial estimation result. It can provide drivers with more interpretable risk warnings and compensation action basis, and provide fusionable stability state quantities for fleet management and intelligent driving / assisted driving systems. This reduces the reliance on drivers' real-time judgment and high-intensity operation under high-risk conditions, thereby improving the safety redundancy and system reliability of the transportation process. Attached Figure Description

[0043] The present invention will be further described below with reference to the accompanying drawings:

[0044] Figure 1This is a schematic diagram of the structure of the present invention;

[0045] Figure 2 for Figure 1 Top view;

[0046] Figure 3 for Figure 1 A bottom view;

[0047] Figure 4 for Figure 2 AA section view in the middle;

[0048] Figure 5 This is a schematic diagram illustrating the control principle for preventing rollover when a vehicle turns right in an embodiment of the present invention;

[0049] Figure 6 This is a diagram illustrating the anti-rollover effect when a vehicle turns to the right in an embodiment of the present invention.

[0050] The meanings of the numbers in the diagram are as follows: 1 is the liquid tank container, 2 is the base plate, 3 is the micro-pressure sensing unit, 4 is the temperature and liquid level sensor, 5 is the inertial measurement unit, 6 is the fusion controller, 7 is the moving counterweight assembly, 71 is the guide rail, 72 is the counterweight slide, 73 is the counterweight block, 8 is the actuator drive assembly, 9 is the power supply and intrinsically safe isolation unit, and 10 is the human-machine interaction and diagnostic unit. Detailed Implementation

[0051] like Figures 1 to 6 As shown, this invention addresses the technical problems of existing vehicles lacking active center of gravity correction, dynamic stability, and robustness during lateral turns. It provides a rollover prevention control system and method for transport vehicles based on micro-pressure gradient sensing and moving counterweight. The pressure gradient at the bottom of the liquid tank is used as a direct observation of the lateral working condition, reflecting the liquid inertial response and reconstructing the lateral acceleration. Compared with existing traditional schemes that rely on acceleration sensors, center of gravity calculation, and torque comparison, this invention has the advantages of more direct principle, simpler calculation, stronger anti-interference ability, faster response speed, lower cost, and better robustness.

[0052] The anti-rollover control system for transport vehicles based on micro-pressure gradient sensing and moving counterweight provided by this invention mainly includes:

[0053] A liquid tank container 1 with internal baffles and anti-wave cavity;

[0054] Base plate 2 for horizontally arranging micro-pressure arrays;

[0055] A micro-pressure sensing unit 3, of piezoresistive or capacitive MEMS type, is embedded in the mounting hole / groove of the base plate 2 and sealed with a sealing ring. Its pressure measuring end is connected to the inside of the liquid tank container 1 through a pressure tapping hole, and is used to collect the pressure at different lateral positions of the tank bottom. Therefore, in the cross-sectional schematic diagram, the pressure measuring end can be seen to be located inside the liquid tank container 1, but the mounting base of the micro-pressure sensing unit 3 is still set on the base plate 2. The MEMS selection criteria are: piezoresistive (low temperature drift, fast dynamic response) or capacitive (low range, high resolution); the range is based on the medium density and maximum liquid level. With maximum lateral acceleration The sampling parameters are selected to meet the following conditions: each channel ≥ 200Hz, synchronization error < 1ms;

[0056] Temperature and level sensor 4 is used to detect the internal liquid temperature T and loading height h of liquid tank container 1. A fusion controller 6 calculates the liquid density from T based on a medium model or lookup table function. ;

[0057] Used to detect pitch angle (around the horizontal axis), roll angle (about the longitudinal axis), yaw rate (around the vertical axis) and turning angle Inertial measurement unit 5, which provides attitude information such as (front wheel angle / steering input);

[0058] A fusion controller 6 for filtering, regression, thresholding, and execution control;

[0059] The movable counterweight assembly 7 is used to set the guide rail 71, counterweight slide 72, counterweight block 73 and corresponding lead screw motor and linear motor. The counterweight slide 72 is also equipped with a position sensor for detecting the current position of the counterweight block 73, specifically a magnetic grating or optical grating displacement sensor.

[0060] Actuator drive assembly 8 for driving and braking locking screw motors and linear motors;

[0061] Power supply and intrinsic safety isolation unit 9 for providing power and intrinsic safety isolation to the system;

[0062] Human-machine interaction and diagnostic unit 10 is used to display alarms, fault codes, and provide maintenance interfaces.

[0063] like Figure 3As shown, in a preferred embodiment, the movable counterweight assembly 7 includes two parallel guide rails 71, a counterweight slide 72, and a counterweight block 73. The counterweight block 73 is fixedly installed on the counterweight slide 72 and moves as a whole with the counterweight slide 72. The actuator drive assembly 8 can be a ball screw motor or a linear motor. When a ball screw motor is used, the two ends of the screw are supported by bearing seats and coaxially connected to the motor. The nut seat is fixedly connected to the counterweight slide 72. The rotation of the motor drives the nut seat and the counterweight slide 72 to reciprocate linearly along the guide rails 71. When a linear motor is used, the stator is fixed to the frame, and the mover is fixedly connected to the counterweight slide 72, causing the counterweight slide 72 to reciprocate along the guide rails 71. The effective stroke of the counterweight block 73 is 0.35m-0.45m from the center position of the transport vehicle frame to the left or right along the lateral direction of the vehicle.

[0064] In use, the fusion controller 6 filters and removes anomalies from the pressure signal, and regresses the pressure-position data within a sliding time window to obtain the pressure gradient. Based on Euler's momentum equation and density model The initial value of lateral acceleration is calculated and then compensated by attitude information. When the compensated lateral acceleration of the vehicle exceeds the threshold and meets the continuous criterion, the fusion controller 6 drives the moving counterweight component 7 to move laterally along the vehicle, so that the projection of the vehicle's center of gravity is kept within the support area formed by the tire contact point, thereby reducing the risk of rollover.

[0065] Specifically, when calculating lateral acceleration, the fusion controller 6 establishes the following vehicle coordinate system: the positive y-axis is taken as the direction of the vehicle's longitudinal movement, the positive x-axis is taken as the right side of the vehicle's longitudinal movement direction, and the positive z-axis is taken vertically upward; the calculated lateral acceleration is denoted as... (Acceleration along the x-axis), pressure gradient Defined as Its sign is consistent with the positive direction of the above coordinates. The moving counterweight component 7 moves in the lateral direction, i.e. the x-axis direction, to compensate for the rollover moment caused by the lateral acceleration of the vehicle when it is turning in a curve.

[0066] like Figure 5 and Figure 6 As shown, with the vehicle along Taking a vehicle traveling at a constant speed in the positive direction of the axis and turning to the right as an example, the vehicle generates a lateral acceleration pointing towards the inside of the curve. ( In the vehicle's body coordinate system, in addition to the downward force of gravity (negative z-axis direction), the liquid inside the tank is also subjected to forces related to gravity. Lateral inertial forces in opposite directions (equivalent centrifugal force, pointing towards) (Negative direction of the axis). Under the action of inertial force and gravity, the free liquid surface tilts to the outside of the curve and is located on the outside of the curve ( Accumulation (in the negative direction of the axis) leads to the accumulation of the medium inside the tank and the equivalent center of mass of the entire vehicle. Shift towards the outside of the curve. The point of contact between the tire and the ground on the outside of the curve. Using the point as the fulcrum, the aforementioned lateral inertial force will cause the vehicle to rotate around... The overturning moment is directed towards the outside of the curve. To counteract this overturning moment, the fusion controller drives the moving counterweight assembly to move the counterweight block towards the inside of the curve. The axis moves in the positive direction, causing the vehicle's equivalent center of gravity to pull back towards the inside of the curve, thus reducing the impact of gravity on the fulcrum. The restoring torque towards the inside of the curve increases and is sufficient to resist the overturning torque, ensuring that the center of gravity projection remains within the support area formed by the tire contact point, thereby maintaining vehicle stability.

[0067] This invention, under the conditions of filtering out high-frequency disturbances such as wave crashing and treating the liquid inside the tank as a quasi-static (gradually varying acceleration) response, neglects the viscous term and local velocity term, taking the vehicle's lateral direction as the x-axis (right side positive) and the vertical direction as the z-axis (upward positive), and using the turning to the right (lateral acceleration) as the basis for the calculation. Taking the positive x-axis as an example, the fluid motion within the transverse section of the vehicle's body coordinate system can be considered as uniformly accelerated linear motion, and the fluid pressure distribution pattern can be obtained by integrating the pressure difference formula:

[0068] ;

[0069] ;

[0070] The liquid pressure gradient is:

[0071] ;

[0072] As a one-dimensional form of the Euler momentum equation, under the condition of gradually varying liquid acceleration and after filtering out the high-frequency components of wave impact, the pressure gradient satisfies the quasi-static one-dimensional Euler equation form, which is used for modeling in the transverse x-axis direction.

[0073] When the bottom surface of the tank is horizontal, the micro-pressure sensing units at the bottom of the tank are located at the same geometric height. If z = z0 is a constant and does not change with x, then the pressure measured at the lateral position on the bottom of the tank is... ,satisfy:

[0074] ;

[0075] When roll angle is not considered, i.e. At that time, the relationship between the pressure gradient at the bottom of the tank on the horizontal plane and the lateral acceleration is:

[0076] ;

[0077] In practical engineering applications, the tank shape of a typical liquid transport vehicle can be cylindrical or elliptical. Furthermore, the bottom surface of the tank's transverse cross-section can be designed as other multi-segment curves depending on the specific circumstances. Therefore, for a general-shaped tank cross-section bottom surface, the sensor pressure-applying ends are distributed along the inner wall of the bottom surface, and their geometric vertical height z typically varies with the transverse position x, which can be denoted as... At this time, the pressure measured at the sensor on the inner wall of the bottom surface is a composite function. ,right Differentiating and applying the chain rule, we can obtain:

[0078] ;

[0079] Considering that cylinders are common in practical engineering due to their uniform stress distribution and ease of maintenance, a cylindrical tank with radius r is used as an example. The origin of the coordinate axis is placed at the center of the cross-section. For the local geometry of the bottom surface of the arc-shaped tank, the coordinates x and z satisfy the following:

[0080] ;

[0081] The z-coordinate of the lower semicircle of the bottom of the can is Then we have:

[0082] ;

[0083] When roll angle is not considered At that time, the pressure gradient measured along the arc-shaped bottom of the tank is:

[0084] ;

[0085] make Let be the angle between the tangent line of the bottom wall at the sensor location and the horizontal plane, then:

[0086] ;

[0087] ;

[0088] Inverse solution for:

[0089] ;

[0090] in The pressure gradient is measured laterally along the bottom of the tank (obtained by a sensor array). The tangent slope is determined by the geometric parameters of the wall surface at the location of the sensor at the bottom of the tank.

[0091] When a vehicle is actually driving on the road, its center of gravity may shift to the outside of the curve during a turn, and the centrifugal force may cause it to tilt slightly to one side, with one wheel as the fulcrum. The lateral tilt angle of the vehicle body (or the vehicle's body coordinate system) about its longitudinal axis is defined as the roll angle. For the example of a right turn, the vehicle may have a roll angle φ tilting to the left. The component of gravity in the body coordinate system can be taken as:

[0092] ;

[0093] Therefore, the pressure difference formula needs to include the component of gravity in the x-axis direction, while the g component in the z-axis direction becomes g. z :

[0094] ;

[0095] The pressure gradient becomes:

[0096] ;

[0097] For the curved bottom surface of a cylindrical tank, the pressure gradient at the bottom surface can be obtained when considering the roll angle φ for attitude compensation:

[0098] ;

[0099] Inverse solution for:

[0100] ;

[0101] For the bottom surface of the horizontal tank, the pressure-sensing end openings of each micro-pressure sensing unit 3 are located at the same geometric height (same) in the vehicle coordinate system. The pressure gradient at the bottom of the tank satisfies The linear relationship, when reconstructing the lateral acceleration from the pressure gradient at the bottom of the tank, only requires considering the pressure difference at different measuring points. Perform linear regression and roll angle attitude compensation.

[0102] For cylindrical, arc-shaped tank bottoms or other generally common tank bottom shapes, the pressure-applying terminals of the micro-pressure sensing unit may be located at different geometric heights under structural geometric constraints. At this point, the pressure difference caused by the geometric height difference at the bottom of the tank will be introduced. This leads to a pressure gradient A deviation has occurred. The pressure gradient at the bottom of the tank still essentially satisfies... A linear relationship is established, but a geometric correction coefficient is needed to correct local errors caused by the bottom curvature. To ensure the accuracy of reconstructing the lateral acceleration from the tank bottom pressure gradient, this invention does not directly address the issue. Instead of performing linear regression, we use the least squares fitting method, specifically as follows:

[0103] Within the sliding time window, the pressure-position relationship can be approximated as a linear field, and the model can be established as follows:

[0104] ;

[0105] right Each measuring point and its pressure measurement Establish the equation:

[0106] ;

[0107] in, The constant term in the regression model represents the baseline pressure level at the origin of the selected vehicle coordinate system. It is used to absorb the position-independent constant influences such as the gas phase pressure inside the tank, the static pressure baseline, and the zero-point offset of the sensor, thereby improving the fitting stability. c1 corresponds to the rate of change of pressure along the lateral coordinate x. Under the corresponding coordinate definition, it can characterize the lateral pressure gradient and is related to the lateral acceleration of the vehicle. c2 corresponds to the rate of change of pressure along the geometric height z. It is used to characterize the pressure change caused by the static pressure due to gravity and the geometric height difference of the pressure tapping end.

[0108] And because:

[0109] ;

[0110] To obtain acceleration We need to find That is, for three points distributed at different heights , , Establish the matrix equation:

[0111] ;

[0112] Thus, the lateral acceleration coefficient c1 and the acceleration coefficient c2 including vertical gravity, as well as the acceleration... .

[0113] In embodiments of the present invention, the provided anti-rollover control system for transport vehicles includes at least three equidistant micro-pressure sensing units 3 disposed in the transverse direction of the bottom plate of the liquid tank container 1 for collecting pressure-position data. Preferably, two or more sets of micro-pressure sensing arrays are arranged along the longitudinal y-direction of the vehicle to obtain multiple sets of pressure-position data under the same conditions, thereby suppressing or eliminating measurement errors caused by only one sensor or only one set of sensors, improving the accuracy and robustness of the pressure gradient inversion results. The fusion controller 6 uses least squares linear regression to fit the pressure-position relationship of each array within a sliding time window to obtain the pressure gradient. The transverse acceleration is calculated based on the inversion relationship between the pressure gradient and the transverse acceleration, and voting, weighted fusion or fault elimination is performed based on the consistency between the estimation results of each array.

[0114] It also includes a fusion controller 6 electrically connected to the micro-pressure sensing unit 3. The fusion controller 6 is configured to take the pressure-position data collected by each micro-pressure sensing unit 3 as input, use a linear regression method to fit the relationship between pressure and lateral position, and obtain the pressure gradient and calculate the vehicle's lateral acceleration accordingly. ,in For liquid density, For vehicle roll angle; when When the set threshold is exceeded and the continuous condition is met, the movable counterweight component 7 installed at the bottom of the vehicle is driven to move laterally so that the projection of the vehicle's center of gravity is kept within the support area formed by the tire contact point (at least within the lateral support range corresponding to the wheel track), thereby reducing the risk of rollover.

[0115] Subsequently, the roll angle was determined based on the quasi-static Euler momentum equation and in conjunction with the inertial measurement pressure gradient unit. Calculate the lateral acceleration of the vehicle The calculation formula is:

[0116] ;

[0117] The calculated lateral acceleration of the vehicle Perform attitude compensation, density Composed of temperature sensor and media library Updated online.

[0118] The fusion controller 6 uses a continuous over-threshold window criterion to avoid false triggering caused by wave crashing (e.g., >0.35g and >300m / s). 2 To further suppress the impact of wave crashing, the first-order characteristic frequency of wave crashing can be used as the calculation formula:

[0119] , ;

[0120] In the formula, It is the acceleration due to gravity. Angular frequency, The first-order wave beat frequency, The wave number is used to characterize spatial frequency, that is, "how fast the wave changes in space" (as opposed to the pressure gradient mentioned above). Used to distinguish here (where h represents wave number) and h represents liquid depth;

[0121] To improve robustness, RANSAC is used to remove outliers within the window before weighted least squares estimation. and to Low-pass / median processing is performed and used as the basis for triggering and displacement mapping. The dual thresholds and duration are preset as follows: Entering the warning phase, and Start the counterweight; and measure the yaw rate using the inertial measurement unit 5. Perform consistency checks to avoid spurious triggers; use the sliding window midpoint and RANSAC robust line fitting for strong wave crashes; add a hysteresis band (e.g., 0.1-0.2 m / s). 2 To prevent boundary jitter, and with yaw rate Perform consistency cross-validation.

[0122] The movable counterweight assembly 7 adopts a dual-rail and ball screw or linear motor structure, with a stroke set to... Displacement closed-loop control satisfies rise time overshoot ;

[0123] The displacement of the counterweight 73 is calculated based on the overturning moment and the restoring moment, and the equivalent mass of the entire vehicle is set as follows. The height of the center of mass is The quasi-static lateral acceleration component is The counterweight mass is Safety factor is Gravitational acceleration Then the overturning moment M O Approximate expression:

[0124] ;

[0125] Corresponding safety requirement torque for:

[0126] ;

[0127] When the lateral displacement of counterweight 73 is When, the restoring torque M generated by the counterweight S Approximately:

[0128] ;

[0129] Therefore, the torque gap ΔM that needs to be compensated can be defined as:

[0130] ;

[0131] Used to indicate the current displacement of the counterweight There is still a torque gap that needs to be compensated, therefore This is used to represent the unique increment that needs to be added, so the target lateral displacement of the counterweight is... The calculation formula is:

[0132] ;

[0133] in, This represents the maximum permissible lateral displacement of the counterweight.

[0134] When the existing restoring torque is ignored (let) When this condition is met, the aforementioned closed loop can degenerate into a lower displacement limit. ,satisfy:

[0135] ;

[0136] It employs an S-curve / velocity and acceleration limiter to prevent secondary oscillations, and implements a mechanical locking and return-to-center strategy after execution.

[0137] This invention also provides a coordinated control function with the Electronic Stability Control (ESC) and Electronic Braking System (EBS): when a high-risk threshold is reached, the outer brake can be linked to the counterweight adjustment to suppress roll and yaw as a whole. To avoid interference between systems, this invention preferably interlocks with the chassis only by risk level / state position and does not directly control the braking torque, defining degradation and failure safety strategies under the functional safety framework (such as ISO 26262).

[0138] This invention applies to transport vehicles including tank trucks and vehicles transporting high-risk liquid chemicals. A micro-pressure sensor array is equidistantly arranged along the lateral side of the liquid container's bottom plate. Specifically, at least three equidistant micro-pressure sensor units are arranged laterally on the liquid container's bottom plate. When the compensated lateral acceleration exceeds a threshold and meets the continuity criterion, the counterweight under the vehicle is moved, keeping the vehicle's center of gravity projection within the support area formed by the tire contact points (at least within the lateral support interval corresponding to the wheel track), reducing the risk of rollover. This invention has advantages such as low cost, robustness to changes in load rate, and easy coordination with electronic stability control (ESC) or electronic braking control (EBS) systems. It represents a significant improvement over existing control schemes that rely solely on suspension or inertial measurement unit (IMU) triggering or simply move the counterweight. This invention employs a collaborative control method involving a multi-point micro-pressure array at the tank bottom, pressure gradient regression, attitude density compensation, lateral acceleration estimation, appropriate displacement counterweight correction, and locking in place. It uses a wave-resistant frequency-time domain combined triggering method, resulting in a simple structure that significantly improves robustness while ensuring feasibility.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle rollover prevention control system based on micro-pressure gradient sensing and moving counterweight, comprising a liquid tank container (1), characterized in that: The liquid tank container (1) is fixed on the transport vehicle frame by the base plate (2), and multiple micro pressure sensing units (3) are arranged laterally at the position where the base plate (2) contacts the liquid tank container (1). A temperature and level sensor (4) is also provided on the liquid tank container (1) to obtain the temperature and level information of the medium inside the liquid tank. An inertial measurement unit (5) for measuring vehicle attitude and lateral acceleration is installed on the liquid tank container (1) or the vehicle frame. The transport vehicle frame is also equipped with a fusion controller (6), a moving counterweight assembly (7), an actuator drive assembly (8), and a power supply and intrinsic safety isolation unit (9). A human-machine interface and diagnostic unit (10) is installed in the driver's cab of the transport vehicle. The mobile counterweight assembly (7) is arranged on the underside of the transport vehicle frame, and the actuator drive assembly (8) is used to drive the mobile counterweight assembly (7) to move adaptively; The human-machine interaction and diagnostic unit (10) is electrically connected to the fusion controller (6) via wires and is used to display alarm information, fault codes and record operating data; The micro-pressure sensing unit (3), temperature and liquid level sensor (4), inertial measurement unit (5), and actuator drive assembly (8) are all electrically connected to the fusion controller (6); The power supply and intrinsic safety isolation unit (9) supplies power to the micro pressure sensing unit (3), temperature and liquid level sensor (4), inertial measurement unit (5), fusion controller (6), and actuator drive assembly (8) respectively, and achieves explosion-proof and intrinsic safety isolation.

2. The anti-rollover control system for transport vehicles based on micro-pressure gradient sensing and moving counterweight as described in claim 1, characterized in that: The movable counterweight assembly (7) includes two guide rails (71) fixed to the lower side of the transport vehicle frame, a counterweight slide (72) that slides along the guide rails (71), and a counterweight block (73) installed on the counterweight slide (72). The counterweight slide (72) is connected to the actuator drive assembly (8) via a ball screw motor or a linear motor. Mechanical limit and buffer structures are provided at both ends of the travel of the guide rail (71); The counterweight slide (72) is also equipped with a position sensor for detecting the current position of the counterweight block (73).

3. The anti-rollover control system for transport vehicles based on micro-pressure gradient sensing and moving counterweight as described in claim 2, characterized in that: The actuator drive assembly (8) includes a motor drive module and a brake control module. The motor drive module is used to drive a ball screw motor or a linear motor. The brake control module is used to control the moving counterweight assembly (7) to stop moving when the system loses power or receives a fault signal, so that the counterweight block (73) stops at the current position or returns to the center position of the guide rail (71).

4. The anti-rollover control system for transport vehicles based on micro-pressure gradient sensing and moving counterweight as described in claim 1, characterized in that: The micro pressure sensing unit (3) is specifically a piezoresistive or capacitive MEMS micro pressure sensor. A temperature compensation circuit is provided inside the micro pressure sensing unit (3), and an explosion-proof and corrosion-resistant structural housing is provided outside. At least three micro-pressure sensing units (3) are set along the vehicle's transverse x-axis at the contact position between the base plate (2) and the liquid tank container (1) to collect liquid pressure data at different transverse positions of the base plate (2).

5. The anti-rollover control system for transport vehicles based on micro-pressure gradient sensing and moving counterweight as described in claim 1, characterized in that: The power supply and intrinsic safety isolation unit (9) includes an on-board power interface, an explosion-proof safety barrier, and an isolated DC / DC converter unit, wherein: The explosion-proof safety barrier is used to limit the electrical energy and voltage entering the hazardous medium area, and the isolated DC / DC conversion unit is used to provide isolated power to the micro pressure sensing unit (3), temperature and liquid level sensor (4) and inertial measurement unit (5).

6. The anti-rollover control system for transport vehicles based on micro-pressure gradient sensing and moving counterweight according to claim 2, characterized in that: The human-machine interaction and diagnostic unit (10) includes a display screen, status indicator lights and a communication interface, which can display the lateral acceleration, the position of the counterweight (73), the system working mode and fault codes in real time, and connect to the vehicle network or external diagnostic equipment through the communication interface for data recording and remote upgrades.

7. The anti-rollover control system for transport vehicles based on micro-pressure gradient sensing and moving counterweight as described in claim 1, characterized in that: The interior of the liquid tank container (1) is also provided with a flow guide baffle and a wave-reflecting cavity.

8. A method for anti-rollover control of a transport vehicle based on micro-pressure gradient sensing and moving counterweight as described in claim 2, characterized in that: The control steps include the following: Step 1: During vehicle operation, multiple micro-pressure sensing units (3) installed on the base plate (2) synchronously collect the bottom pressure values ​​at various lateral positions of the vehicle and record the position coordinates (x, y) of the corresponding measuring points in the vehicle coordinate system. i , z i ), where x i The position coordinates of the pressure-sensing unit (3) at the pressure-applying end opening in the vehicle coordinate system along the transverse x-axis are given by z. i The geometric height of the pressure-sensing unit (3) is the opening of the pressure terminal. If all measuring points are at the same height, then z i It is a constant; Step 2: The filtering and regression calculation module inside the fusion controller (6) performs low-pass filtering and / or Kalman filtering on the pressure signal collected by the micro-pressure sensing unit (3), and performs outlier removal and data processing within the sliding time window to obtain the pressure-position dataset for regression, expressed as: ， ； in, The lower horizontal edge of the vehicle coordinate system Position coordinates along the axis The slope of the pressure-position relationship. For pressure, For the density of the liquid, For the pressure gradient, satisfying ; Step 3: The fusion controller (6) establishes a pressure-position regression model within the sliding time window based on the quasi-static linear assumption of the pressure field, with the following expression: ； Where, p i The pressure value measured by the i-th micro-pressure sensing unit (3), (x i , z i ) represents the lateral coordinates and geometric height coordinates of the measuring point in the vehicle coordinate system, and N represents the number of measuring points; The fusion controller (6) uses the least squares method to estimate the parameters of the pressure-position regression model, and the calculation formula is as follows: ； Where c0 is a constant term in the regression model, representing the reference pressure level at the origin of the selected vehicle coordinate system, thus obtaining the lateral acceleration coefficient c1 and the vertical gravity acceleration coefficient c2. Step 4: The fusion controller (6) is based on the quasi-static form of the Euler momentum equation and combines the roll angle measured by the inertial measurement unit (5). The lateral acceleration coefficient c1 obtained in step three is converted into the initial value of the vehicle's lateral acceleration. The calculation formula is: ； in, Where is the density of the liquid; g is the acceleration due to gravity; Step 5: If the compensated lateral acceleration of the vehicle exceeds the preset threshold of the fusion controller (6) and continues for a set time, the fusion controller (6) outputs a control command to the actuator drive component (8) to drive the moving counterweight component (7) to move so that the center of gravity projection of the entire transport vehicle remains within the support area formed by the tire contact point.

9. The method for anti-rollover control of a transport vehicle based on micro-pressure gradient sensing and moving counterweight according to claim 8, characterized in that: Before processing the pressure signal, step two involves using RANSAC or residual threshold methods to remove outliers from the pressure-position data and constructing a health index based on the regression residuals for online monitoring of the performance of the micro-pressure sensing unit (3).

10. The method for anti-rollover control of a transport vehicle based on micro-pressure gradient sensing and moving counterweight according to claim 9, characterized in that: The specific method for moving the moving counterweight component (7) in step five is as follows: When the compensated vehicle lateral acceleration When the first threshold preset by the fusion controller (6) is continuously exceeded, the fusion controller (6) controls the counterweight slide (72) to carry the counterweight block (73) to move along the guide rail (71) in the same direction as the calculated target displacement in the x-axis direction of the vehicle to compensate for the lateral acceleration. When the compensated vehicle lateral acceleration After descending to below the second threshold preset by the fusion controller (6) and holding for a set time, the fusion controller (6) controls the counterweight slide (72) to carry the counterweight block (73) back to the safe position or center position along the guide rail (71).

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