Vehicle stability calculation method

Abstract

The present invention discloses a vehicle stability calculation method, which relates to the field of vehicle roll stability testing and is used to test the possibility of a vehicle overturning after falling into a pit. The vehicle stability calculation method includes the following steps: calculating the distance between the center of gravity of the vehicle and the ground when the instantaneous speed of the vehicle is zero after the vehicle falls into the pit, and the distance is recorded as the first distance; calculating the distance between the center of gravity of the vehicle and the ground in the critical state of overturning after the vehicle falls into the pit, and the distance is recorded as the second distance; calculating the difference between the second distance and the first distance; if the difference is greater than the set value, the vehicle will not overturn; otherwise, the vehicle will overturn. After the vehicle falls into the pit, the trajectory of the center of gravity of the vehicle changes from a normal driving position to a gradually lower position and then gradually higher. The first distance corresponds to the highest center of gravity position finally reached by the vehicle after falling into the pit. The above technical solution judges whether the vehicle will overturn based on the relationship between the first distance and the second distance.

Description

Technical Field

[0001] The present invention relates to the field of vehicle roll stability testing, and in particular to a vehicle stability calculation method. Background Art

[0002] A mobile lifting work platform may have one or more wheels fall into a pothole while in motion. During the design of a mobile lifting work platform, it is necessary to ensure that it does not tip over when one or both wheels fall into a pothole.

[0003] The inventors discovered at least the following problems with the prior art: In the related art, during the design process of a mobile elevating work platform, prototype testing is used to verify whether the vehicle will overturn. However, because prior art only calculates static stability and dynamic stability due to curb impact during the vehicle design phase, there is no method to calculate the situation where wheels fall into pits. Therefore, the probability of problems occurring during testing is high. A rollover accident during vehicle testing poses a significant safety risk, and repeated vehicle modifications result in design changes, hindering project progress. Summary of the Invention

[0004] The present invention provides a vehicle stability calculation method for calculating the possibility of a vehicle overturning after falling into a pit.

[0005] Some embodiments of the present invention provide a method for calculating vehicle stability, comprising the following steps:

[0006] Obtaining a first distance, where the first distance is the distance between the center of gravity of the vehicle and the ground when the instantaneous speed of the vehicle is zero after the vehicle falls into the pit;

[0007] Obtaining a second distance, where the second distance is the distance between the center of gravity of the vehicle and the ground in a critical overturning state after the vehicle falls into the pit;

[0008] calculating a difference between the second distance and the first distance;

[0009] If the difference is greater than a set value, it is determined that the vehicle will not overturn; if the difference is less than or equal to the set value, it is determined that the vehicle will overturn.

[0010] In some embodiments, the first distance is obtained according to the following steps: obtaining the distance between the center of gravity of the vehicle and the ground when the vehicle is traveling on the ground as the first distance.

[0011] In some embodiments, the first distance is obtained according to the following steps:

[0012] Build a 3D model of the vehicle;

[0013] Building a simplified model of the vehicle based on the three-dimensional model of the vehicle;

[0014] marking the location of the center of gravity of the vehicle in a simplified model of the vehicle;

[0015] The distance between the center of gravity of the vehicle and the ground is calculated as the first distance according to the coordinates corresponding to the position of the center of gravity of the vehicle.

[0016] In some embodiments, the second distance is calculated according to the following steps:

[0017] In the simplified model of the vehicle, a critical model corresponding to the critical state of the vehicle's rollover is added;

[0018] Moving the center of gravity of the vehicle along the overturning trajectory of the vehicle to the critical surface of the critical model to determine the position of the center of gravity of the vehicle in the overturning critical state;

[0019] The distance between the center of gravity of the vehicle and the ground is calculated as the second distance based on the coordinates corresponding to the position of the center of gravity of the vehicle in the critical rollover state.

[0020] In some embodiments, the set value is 0 to 5 cm.

[0021] In some embodiments, the vehicle is a mobile elevating work platform.

[0022] In some embodiments, the vehicle falling into the pit means that at least one wheel of the vehicle falls into the pit.

[0023] In some embodiments, the depth of the pit is less than or equal to 100 mm.

[0024] In some embodiments, the vehicle stability calculation method further includes the following steps: if the difference is greater than a set value, determining that the design of the vehicle meets the stability design requirements.

[0025] The vehicle stability calculation method provided by the above technical solution determines whether the vehicle is in danger of overturning based on the position of the vehicle's center of gravity. First, the first distance between the vehicle's center of gravity and the ground is calculated when the vehicle's instantaneous speed is zero after falling into the pit. This first distance can be used to determine the position of the vehicle's center of gravity. After the vehicle falls into the pit, the trajectory of the vehicle's center of gravity changes from the center of gravity in the vehicle's driving state to the position where the vehicle's speed is instantaneously zero. In other words, the vehicle's center of gravity position gradually decreases from the normal driving position and then gradually increases. The first distance corresponds to the highest center of gravity position reached after the vehicle falls into the pit. The relationship between this first distance and the second distance between the vehicle's center of gravity and the ground at the critical state of vehicle overturning is used to determine whether the vehicle will overturn. If the difference between the second distance and the first distance is greater than a set value, it is determined that the vehicle will not overturn; if the difference is less than or equal to the set value, it is determined that the vehicle will overturn. The above technical solution provides a simple and operational calculation method, which enables the possibility of vehicle overturning to be calculated and judged during the vehicle design stage, greatly reducing the workload of repeatedly modifying the design based on verification results and improving vehicle design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 A schematic flow chart of a vehicle stability calculation method provided in some embodiments of the present invention.

[0028] Figure 2 A schematic diagram of a flow chart of calculating a first distance in a vehicle stability calculation method provided in some embodiments of the present invention.

[0029] Figure 3 A schematic diagram of a flow chart of calculating a second distance in a vehicle stability calculation method provided in some embodiments of the present invention.

[0030] Figure 4 Schematic diagram of a vehicle model provided for some embodiments of the present invention.

[0031] Figure 5 Schematic diagram of a simplified vehicle model corresponding to the vehicle stability calculation method provided in some embodiments of the present invention.

[0032] Figure 6 Schematic diagram of simplified models of a vehicle in various states corresponding to the vehicle stability calculation method provided in some embodiments of the present invention.

[0033] Figure 7 A schematic structural diagram of a vehicle stability calculation system provided in some other embodiments of the present invention.

[0034] Reference numerals: 10, first distance obtaining module; 20, second distance obtaining module; 30, difference calculation module; 40, overturning determination module; 50, stability determination module. DETAILED DESCRIPTION

[0035] The following combination Figures 1 to 7 The technical solution provided by the present invention is described in more detail.

[0036] See also Figures 1 to 6 Some embodiments of the present invention provide a method for calculating vehicle stability, wherein the vehicle is a mobile lifting work platform. Mobile lifting work platforms are mainly used in industries such as construction, steel structures, venues, and leasing. As an engineering equipment for manned operations, the safety of the mobile lifting work platform is extremely important, and the stability of the entire vehicle is adjusted by counterweights. The mobile lifting work platform is used to transport people and objects from one height to another to complete high-altitude operations, high-altitude material transportation, and other needs. The weight of people and objects carried by the lifting work platform is related to the structural dimensions of the platform, and can generally meet the lifting needs of one or more people. The maximum operating height of the lifting work platform is generally 4 meters to 70 meters.

[0037] Lifting work platforms include boom-type lifting work platforms and scissor-type lifting work platforms. These types can all be designed and calculated using the technical solutions provided in the embodiments of the present invention. The following will take the boom-type lifting work platform as an example for a detailed description.

[0038] The lifting work platform includes an alighting mechanism, a luffing mechanism, a first counterweight, a second counterweight, an arm and a platform.

[0039] The disembarkation mechanism is constructed to provide support. The structural dimensions of the disembarkation mechanism are related to the specific vehicle model. The disembarkation mechanism includes a frame and a turntable. A running mechanism is installed at the bottom of the frame, and the running mechanism is located on the ground. There are many types of running mechanisms: crawler running mechanisms, wheeled running mechanisms, circular rail running mechanisms, etc. In some embodiments, in order to facilitate transfer transportation, the running mechanism adopts a wheeled running mechanism, that is, tires. Tires have good maneuverability on hard ground, and the transfer transportation is fast and efficient, which can meet emergency needs such as high-altitude firefighting and rescue.

[0040] The turntable is rotatably mounted to the vehicle frame. It rotates along its circumference to change the position and orientation of the boom, enabling the boom to operate in different directions. While the turntable's dimensions are not limited, it generally allows for 360° rotation. This allows the boom and its connected platform to be positioned to meet operational and rescue needs regardless of the platform's docking position.

[0041] The luffing mechanism is installed on the dismounting mechanism, specifically on the turntable. The luffing mechanism is a mechanism that can change the tilt angle relative to the ground. There are many forms of implementation of the luffing mechanism. In some embodiments, the luffing mechanism includes a parallelogram mechanism, which is composed of multiple truss arms, and the arrangement of these truss arms is determined according to parameters such as the weight of the lifted boom. The action of the luffing mechanism is divided into two: one is called the first luffing, and the other is called the second luffing. If the boom is slowly raised, the process is called the first luffing, or the upper luffing. The upper luffing gradually increases the height of the people and objects carried by the platform to meet the needs of high-altitude operations, high-altitude rescue, etc. If the boom is slowly lowered, the process is called the second luffing, or the lower luffing. The lower luffing gradually reduces the height of the people and objects carried by the platform to meet the needs of returning to the ground, low-altitude operations, low-altitude rescue, etc.

[0042] During the transport or operation of a mobile work platform, if it encounters uneven terrain, its traveling mechanism may fall into a pit, causing the mobile work platform to tilt. If the mobile work platform tilts too much, it may overturn, creating a dangerous situation. Therefore, during the design and manufacturing process of a mobile work platform, it is necessary to determine in advance the type of road surface the mobile work platform can travel on to ensure the safety of the mobile work platform during operation and transport.

[0043] The inventors discovered that prior art, when testing and verifying vehicle prototypes, only analyzes the static stability of the vehicle and its dynamic stability in the event of a curb impact. These analyses fail to consider the potential risk of overturning if one or more wheels of the vehicle fall into a pit. After extensive and creative effort, the inventors identified this technical issue and proposed the following solution.

[0044] See also Figures 1 to 6 An embodiment of the present invention provides a vehicle stability calculation method, which includes the following steps:

[0045] Step S100: Obtain a first distance. The first distance is the distance between the center of gravity of the vehicle and the ground when the instantaneous velocity of the vehicle is zero after the vehicle falls into the pit. The instantaneous velocity is specifically the instantaneous descent velocity or the instantaneous ascent velocity.

[0046] According to design specifications, for mobile elevating work platforms, the pit depth is less than or equal to 100mm. Therefore, the test was conducted with a pit depth of 100mm. For other vehicle models, the maximum pit depth needs to be determined based on the requirements of the vehicle model.

[0047] In some embodiments, a vehicle falling into a pit refers to at least one of the vehicle's wheels falling into the pit. Based on the wheel's installation position on the vehicle, from the driver's perspective, the wheels can be further divided into the right rear wheel (represented as tire A), the left rear wheel (represented as tire B), the left front wheel (represented as tire C), and the right front wheel (represented as tire D). For example, if the right side tires A and D fall into the pit, the vehicle will tilt to the right.

[0048] The change in the vehicle's state during the pit entry process is calculated through energy conversion. The law of conservation of energy is used to calculate the change in the vehicle's center of gravity as kinetic energy and potential energy are converted into each other, thereby calculating the change in the vehicle's state. Specifically, after the vehicle falls into the pit, the gravitational potential energy of the vehicle is converted into the kinetic energy of the vehicle's downward movement. According to the law of conservation of energy, kinetic energy is maximized at a point where gravitational potential energy is zero, and potential energy is maximized at a point where kinetic energy is zero.

[0049] The process of a vehicle falling into a pit can be divided into two processes: In the first process, the gravitational potential energy of the vehicle is completely converted into kinetic energy, that is, the center of gravity of the vehicle is Figure 6 The second process is that the kinetic energy of the vehicle is completely converted into gravitational potential energy, that is, the center of gravity of the vehicle moves from Figure 5 The b' position shown is moved to the c' position.

[0050] Since the vehicle's kinetic energy is zero at position a' and zero at position c', the law of conservation of energy indicates that the gravitational potential energy at positions a' and c' is equal. Therefore, the center of gravity at positions a' and c' is also the same. The center of gravity at position c' corresponds to the vehicle's instantaneous descent velocity of zero.

[0051] Therefore, in some embodiments, the first distance is calculated according to the following steps: obtaining the distance between the center of gravity of the vehicle and the ground when the vehicle is traveling on the ground as the first distance. It should be noted that the reference points for calculating the first distance and the second distance are the same, such as the bottom of a pit or the road surface.

[0052] As the vehicle enters a pit, its center of gravity drops, and potential energy is converted into kinetic energy. The kinetic energy of the tires touching the ground will cause the vehicle to continue moving in the direction of overturning, and this kinetic energy causes the center of gravity to rise. According to the law of conservation of energy, assuming that all kinetic energy is converted into potential energy, if the final center of gravity exceeds the rollover line, the vehicle will overturn; if it does not exceed the rollover line, the vehicle will not overturn.

[0053] This technical solution, combining the dynamic changes in the center of gravity of the vehicle and the conversion of kinetic and potential energy, calculates the vehicle's state boundaries during motion, resolving the issue of complex dynamic loads that hinder accurate calculation and enabling the calculation of dynamic pit entry stability. By simulating the pit entry process and calculating the most dangerous state possible after entering the pit, the critical state of vehicle rollover is calculated using the principle of energy conservation. By comparing these two states, the likelihood of a vehicle rollover is determined.

[0054] Figure 5 The d' position in the middle indicates the position of the vehicle's center of gravity when the vehicle is in a critical state of overturning. For the same size pit and the same size vehicle, this position is fixed and unchanged.

[0055] Of course, see Figure 2 , it is also possible to calculate the first distance between the center of gravity of the vehicle and the ground after the vehicle falls into the pit in a modeling manner according to the following steps.

[0056] Step S101: Create a three-dimensional model of the vehicle.

[0057] Step S102: Create a simplified model of the vehicle based on the three-dimensional model of the vehicle.

[0058] Simplify the state of the vehicle before entering the pit as follows Figure 5 , lock the floating axle at a position where the height difference between the left and right wheels is Δh.

[0059] When a vehicle is traveling on uneven ground, the heights of the various tires of the vehicle may be different. When the boom is in a non-working state, the axle can be adjusted to adapt to the unevenness of the road surface. After falling into a pothole, if there is a height difference between the left and right wheels of the vehicle, the risk of the vehicle overturning is greater and overturning is more likely to occur. The maximum value of the height difference Δh between the left and right wheels is the maximum value of the axle floating value. The minimum value of the height difference Δh between the left and right wheels is 0. The technical solution of the embodiment of the present invention locks the axle at a position where there is a height difference between the left and right wheels, which can better simulate the risk of vehicle overturning in the most dangerous situation, thereby making more accurate calculations and judgments.

[0060] Step S103: Mark the position of the center of gravity of the vehicle in the simplified model of the vehicle, see Figure 6 shown.

[0061] Step S104: Calculate a first distance between the center of gravity of the vehicle and the ground according to the coordinates corresponding to the position of the center of gravity of the vehicle.

[0062] In a three-dimensional model, the position coordinates of the center of gravity can be obtained directly in the software, so there is no need to use complex formulas for calculation.

[0063] The technical solution of the embodiment of the present invention adopts a very clever solution to solve the very complex problem of the center of gravity position. It is not only highly efficient and accurate, but also can greatly improve the efficiency of vehicle stability testing, improve vehicle design efficiency and shorten the design cycle.

[0064] Step S200: Obtain a second distance. The second distance is the distance between the center of gravity of the vehicle and the ground when the vehicle falls into the pit and is in a critical overturning state.

[0065] See also Figure 3 In some embodiments, the second distance is calculated according to the following steps.

[0066] Step S201: Add a critical model corresponding to the critical rollover state of the vehicle to the simplified model of the vehicle.

[0067] The simplified model obtained in step S102 is assembled, and the positions before the vehicle enters the pit, when the tires touch the ground after entering the pit (this step can also be omitted), the extreme position of continuing to flip after entering the pit, and the critical position of tipping over are assembled in the same model. Whether the vehicle has tipped over is determined by comparing the center of gravity heights of the critical point of tipping over and the extreme position of continuing to flip after entering the pit.

[0068] Step S202: Move the center of gravity of the vehicle to the critical surface along the overturning trajectory of the vehicle to determine the position of the center of gravity of the vehicle in the critical state of overturning. The straight line where the center of gravity is located is perpendicular to the vehicle chassis, see Figure 6 .

[0069] The critical plane is the vertical plane connecting the points of contact between the vehicle's two wheels and the ground at the moment of the vehicle's rollover. This vertical plane is also called the vertical plane, which is perpendicular to the horizontal plane.

[0070] Determine the location of the vehicle's center of gravity in the critical rollover state using the following steps: Figure 5 and Figure 6 , suppose tire A falls into a pit. The movement process of the vehicle falling into the pit is as follows: after tire A falls into the wheel, tire C will tilt up, and wheels B and D will remain in contact with the ground. The entire vehicle rotates around the line connecting the contact points of tires B and D with the ground until tire A contacts the bottom of the pit. After tire A contacts the bottom of the pit, as the entire vehicle overturns and the movement trend, tire B may tilt up and leave the ground, then tire A of the vehicle contacts the bottom of the pit and tire D contacts the ground. At this time, the line connecting the contact point between tire A and the bottom of the pit and the contact point between tire D and the ground is on the same vertical plane. Assuming that the center of gravity of the vehicle moves to the vertical plane, the position of the center of gravity of the vehicle on the vertical plane is the position of the center of gravity of the vehicle in the critical state of overturning. The trajectory of the above-mentioned change of the center of gravity of the vehicle is also the overturning trajectory of the vehicle.

[0071] In the above step S202, a three-dimensional modeling method is used to determine the position of the center of gravity of the vehicle in the critical rollover state in the model without the need for additional calculation formulas.

[0072] Step S203: Calculate a second distance between the center of gravity of the vehicle and the ground based on the coordinates corresponding to the position of the center of gravity of the vehicle in the critical rollover state.

[0073] In a three-dimensional model, after the position of the center of gravity is determined, the coordinates of the center of gravity can be obtained directly from the three-dimensional model without the need for calculation using formulas.

[0074] Step S300: Calculate the difference between the second distance and the first distance.

[0075] The difference between the second distance H2 and the first distance H1, ie, H2-H1, is calculated to determine the relationship between the difference and the set value.

[0076] Step S400: If the difference is greater than the set value, it is determined that the vehicle will not overturn; if the difference is less than or equal to the set value, it is determined that the vehicle will overturn.

[0077] In some embodiments, the set value is 0-5 cm, specifically 1 cm, 2 cm, 3 cm, 5 cm, etc. The larger the set value, the better the stability of the vehicle.

[0078] If the difference between H2 and H1 is greater than the set value, it means that after the vehicle falls into the pit, the distance between the center of gravity and the critical position of overturning is greater, that is, the greater the vehicle stability margin, the safer the vehicle is and the less likely it is to overturn.

[0079] If the difference between H2 and H1 is less than or equal to the set value, it means that the smaller the distance between the center of gravity and the overturning critical position, the greater the risk of the vehicle overturning.

[0080] If the difference is greater than the set value, the vehicle design meets the stability design requirements; if the difference is less than or equal to the set value, the vehicle is redesigned. Redesigning the vehicle means changing the overall layout of the vehicle to change the position of the vehicle's center of gravity.

[0081] For a pothole of a specified size, the vehicle must be able to safely navigate it according to industry standards and specifications. If the vehicle is in danger of overturning, the vehicle design does not meet the requirements. In this case, the vehicle parameters must be redesigned until the vehicle meets the stability requirements and does not overturn during the vehicle stability test.

[0082] This technical solution ensures the dynamic stability of a mobile elevating work platform when entering a pit, ensuring it will not tip over. This addresses the issue of being unable to calculate dynamic stability during pit entry during design calculations. This solution establishes a simplified model of the entire vehicle in 3D software and simulates the various states of the vehicle entering the pit. This solution combines energy methods to calculate the tipping boundary of the vehicle's stability. By comparing the pit entry state with the calculated results, the likelihood of the vehicle tipping over and the stability margin can be determined.

[0083] It should be noted that the above embodiment is introduced using a mobile lifting work platform as an example. Because the mobile lifting work platform is set to a relatively low driving speed, and the most dangerous tipping direction is perpendicular to the driving direction, the driving speed has little impact, so the impact of the driving speed is not taken into account when considering the law of conservation of energy. For other vehicles, if the driving speed is relatively high and the tipping direction is in the same direction as the driving speed, the impact of the driving speed needs to be taken into account. Then, the sum of the vehicle's driving kinetic energy, falling kinetic energy, and gravitational potential energy before the vehicle enters the pit is equal to the sum of the vehicle's driving kinetic energy, falling kinetic energy, and gravitational potential energy after the vehicle enters the pit.

[0084] See also Figure 7 Other embodiments of the present invention provide a vehicle stability calculation system for executing the vehicle stability calculation method provided by any of the above technical solutions. The vehicle stability calculation system includes a first distance acquisition module 10, a second distance acquisition module 20, a difference calculation module 30, and a rollover determination module 40.

[0085] The first distance obtaining module 10 is configured to obtain a first distance H1, which is the distance between the center of gravity of the vehicle and the ground when the vehicle's instantaneous velocity is zero after the vehicle falls into the pit. The first distance obtaining module 10 obtains this distance, for example, using a sensor, or using a program in a three-dimensional model, or by calculating the vehicle's center of gravity.

[0086] The second distance acquisition module 20 is configured to acquire a second distance H2. The second distance H2 is the distance between the vehicle's center of gravity and the ground in a critical overturning state after the vehicle falls into a pit. The second distance acquisition module 20 acquires this distance, for example, using a sensor, a program within a three-dimensional model, or by calculating the vehicle's center of gravity.

[0087] The difference calculation module 30 is configured to calculate the difference between the second distance H2 and the first distance H1. The difference calculation module 30 may be implemented by, for example, a calculator or a calculation program with a calculation function.

[0088] The rollover determination module 40 is configured to determine whether the vehicle will rollover based on the difference calculated by the difference calculation module. If the difference is greater than a set value, the vehicle is determined not to rollover; if the difference is less than or equal to the set value, the vehicle is determined to rollover.

[0089] In some embodiments, the vehicle stability calculation system further includes a stability determination module 50. The stability determination module 50 is configured to determine whether the vehicle stability meets the requirements based on the difference. If the difference is greater than a set value, it is determined that the vehicle design meets the stability design requirements.

[0090] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0091] The present disclosure also provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the aforementioned embodiment of the control method.

[0092] In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, including any media that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks typically reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0093] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the protection content of the present invention.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A vehicle stability calculation method, characterized in that: The following steps are involved: Obtaining a first distance, where the first distance is the distance between the center of gravity of the vehicle and the ground when the instantaneous speed of the vehicle is zero after the vehicle falls into the pit; Obtaining a second distance, where the second distance is the distance between the center of gravity of the vehicle and the ground in a critical overturning state after the vehicle falls into the pit; calculating a difference between the second distance and the first distance; If the difference is greater than a set value, it is determined that the vehicle will not overturn; if the difference is less than or equal to the set value, it is determined that the vehicle will overturn; The first distance is obtained according to the following steps: Build a 3D model of the vehicle; Building a simplified model of the vehicle based on the three-dimensional model of the vehicle; marking the location of the center of gravity of the vehicle in a simplified model of the vehicle; Calculating the distance between the center of gravity of the vehicle and the ground as the first distance based on the coordinates corresponding to the position of the center of gravity of the vehicle; The second distance is calculated according to the following steps: In the simplified model of the vehicle, a critical model corresponding to the critical state of the vehicle's rollover is added; Moving the center of gravity of the vehicle along the overturning trajectory of the vehicle to the critical surface of the critical model to determine the position of the center of gravity of the vehicle in the overturning critical state; The distance between the center of gravity of the vehicle and the ground is calculated as the second distance based on the coordinates corresponding to the position of the center of gravity of the vehicle in the critical rollover state.

2. The vehicle stability calculation method according to claim 1, characterized in that: The first distance is obtained according to the following steps: when the vehicle is traveling on the ground, the distance between the center of gravity of the vehicle and the ground is obtained as the first distance.

3. The vehicle stability calculation method according to claim 1, characterized in that: The set value is 0 to 5 cm.

4. The vehicle stability calculation method according to claim 1, characterized in that: The vehicle is a mobile lifting work platform.

5. The vehicle stability calculation method according to claim 1, characterized in that: The vehicle falling into the pit means that at least one wheel of the vehicle falls into the pit.

6. The vehicle stability calculation method according to claim 1, characterized in that: The depth of the pit is less than or equal to 100 mm.

7. The vehicle stability calculation method according to claim 1, characterized in that: The following steps are also included: If the difference is greater than a set value, it is determined that the design of the vehicle meets the stability design requirement.

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