Horizontal wheel rigidity control method, device and equipment and storage medium

Abstract

The invention discloses a horizontal wheel rigidity control method, device and equipment and a storage medium, and is applied to the field of train control. The method comprises the steps that a stress analysis model of a straddle type monorail vehicle is established, target guiding torque is determined, the target guiding torque is input into the stress analysis model, and tire radial force is obtained; obtaining the radial compression amount of the tire under the target guiding moment, and determining the target rigidity of the horizontal wheel based on the radial force of the horizontal wheel in the radial force of the tire and the radial compression amount of the horizontal wheel in the radial compression amount of the tire; determining a rigidity-tire pressure correlation model, and inputting the target rigidity of the horizontal wheel into the rigidity-tire pressure correlation model to obtain target tire pressure of the horizontal wheel; and the tire pressure of the horizontal wheel is adjusted to the target tire pressure of the horizontal wheel, so that the rigidity of the horizontal wheel reaches the target rigidity of the horizontal wheel. According to the method disclosed by the invention, the rigidity control of the horizontal wheels is realized by adjusting the tire pressure of the horizontal wheels, so that the straddle type monorail vehicle has better anti-overturning capability when passing through a curve.

Description

Technical Field

[0001] The present invention relates to the field of train control, and in particular to a horizontal wheel stiffness control method, device, equipment and computer-readable storage medium. Background Art

[0002] The lateral spacing of the running wheels of straddle-type monorail vehicles is very small, and the vehicle's anti-overturning ability is guaranteed by the contact between the horizontal wheels and the side of the track. If the radial force of the horizontal wheels is 0, the vehicle's anti-overturning ability through the curved line is insufficient, and the vehicle will then deviate from the track beam, causing a major safety accident. If the pre-pressure of the horizontal wheels increases, the vehicle's anti-rolling ability will be enhanced, and the vehicle's curve passing performance will also be improved, but it will also directly increase the wear of the running wheels and the horizontal tire surface, affecting the service life of the rubber wheels. Secondly, if the vehicle speed is too high, the vehicle is subjected to excessive centrifugal force, and the inclination angle is larger, the lateral displacement of the horizontal wheels will be greater than the pre-compression of the horizontal wheels, and the horizontal wheels will deviate from the track surface. Therefore, it is necessary to actively adjust the stiffness of the horizontal wheels to achieve better overturning stability. Summary of the invention

[0003] The object of the present invention is to provide a horizontal wheel stiffness control method, device, equipment and computer-readable storage medium, which are applied to the field of train control. The method realizes the stiffness control of the horizontal wheel by adjusting the tire pressure of the horizontal wheel, so that the straddle-type monorail vehicle has better anti-overturning ability when passing through a curve.

[0004] In order to solve the above technical problems, the present invention provides a horizontal wheel stiffness control method, comprising:

[0005] Establishing a force analysis model of a straddle-type monorail vehicle, determining a target steering torque, inputting the target steering torque into the force analysis model, and obtaining a tire radial force;

[0006] Acquire the radial compression of the tire under the target steering torque, and determine the horizontal wheel target stiffness based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression;

[0007] Determining a stiffness-tire pressure correlation model, and inputting the horizontal wheel target stiffness into the stiffness-tire pressure correlation model to obtain the horizontal wheel target tire pressure;

[0008] The tire pressure of the horizontal wheel is adjusted to the horizontal wheel target tire pressure so that the stiffness of the horizontal wheel reaches the horizontal wheel target stiffness.

[0009] Optionally, the method further includes:

[0010] Acquiring a running wheel speed, and determining a vehicle slip rate based on the running wheel speed;

[0011] If the slip ratio is greater than the slip ratio threshold, determining a running wheel target tire pressure that is lower than a running wheel current tire pressure;

[0012] Sending the running wheel target tire pressure to a tire pressure regulating system so that the tire pressure regulating system regulates the tire pressure of the running wheel to the running wheel target tire pressure;

[0013] Determine the running wheel friction coefficient based on the running wheel target tire pressure, and determine the running wheel adhesion torque based on the running wheel friction coefficient, the running wheel radial force in the tire radial force, and the running wheel tire radius;

[0014] A torque command is sent to the motor controller of the running wheel to control the running wheel driving torque to be smaller than the running wheel adhesion torque.

[0015] Optionally, the method further includes:

[0016] Determine a tire measured radial force based on the tire compression, and determine an equivalent radial force based on the tire measured radial force;

[0017] Determine the radial force threshold based on the maximum radial force of the guide wheel, the maximum radial force of the stabilizing wheel and the maximum radial force of the running wheel;

[0018] If the equivalent radial force is greater than the radial force threshold, the target steering torque is re-determined.

[0019] Optionally, the method further includes:

[0020] Establishing a horizontal wheel radial force-vehicle speed-curve radius correlation model, inputting the vehicle speed and curve radius into the horizontal wheel radial force-vehicle speed-curve radius correlation model, and obtaining a reference horizontal wheel radial force output by the model;

[0021] If the horizontal wheel radial force is not equal to the reference horizontal wheel radial force, redetermining the target steering torque;

[0022] The expression of the horizontal wheel radial force-vehicle speed-curve radius correlation model is:

[0023] F jz-i =μ i1 +μ i2 *v 2 +μ i3 *R;

[0024] In the formula, F jz-i is the reference horizontal wheel radial force of the i-th horizontal wheel, μ i1 , μ i2 and μ i3 is the constant coefficient of the i-th horizontal wheel, v is the vehicle speed, and R is the curve radius.

[0025] Optionally, the method further includes:

[0026] Establishing a bogie offset angle constraint model, and if the bogie offset angle does not satisfy the bogie offset angle constraint model, re-determining the target steering torque;

[0027] The expression of the bogie offset angle constraint model is:

[0028]

[0029] Where θ is the bogie offset angle, is the vehicle angular acceleration, and t is the vehicle running time when passing the curve.

[0030] Optionally, the method further includes:

[0031] Establishing a guiding torque constraint model, determining the root mean square of the guiding torque when the curve passes through, and re-determining the target guiding torque if the root mean square of the guiding torque does not satisfy the guiding torque constraint model;

[0032] The expression of the guiding moment constraint model is:

[0033]

[0034] Where M rms is the root mean square of the guiding torque, M max is the maximum guiding torque, I z is the moment of inertia, A is the longitudinal distance between the guide wheels, R is the curve radius, and v is the vehicle speed.

[0035] Optionally, adjusting the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel includes:

[0036] The horizontal wheel target tire pressure is sent to a tire pressure regulation system, so that the tire pressure regulation system regulates the tire pressure of the horizontal wheel to the horizontal wheel target tire pressure.

[0037] In order to solve the above technical problems, the present invention provides a horizontal wheel stiffness control device, comprising:

[0038] The first module is used to establish a force analysis model of a straddle-type monorail vehicle, determine a target steering torque, input the target steering torque into the force analysis model, and obtain a tire radial force;

[0039] The second module is used to obtain the radial compression of the tire under the target steering torque, and determine the horizontal wheel target stiffness based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression;

[0040] A third module is used to determine a stiffness-tire pressure correlation model, and input the horizontal wheel target stiffness into the stiffness-tire pressure correlation model to obtain the horizontal wheel target tire pressure;

[0041] The fourth module is used to adjust the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel so that the stiffness of the running wheel reaches the target stiffness of the horizontal wheel.

[0042] In order to solve the above technical problems, the present invention provides a horizontal wheel stiffness control device, comprising:

[0043] Memory, for storing computer programs;

[0044] A processor is used to implement the above-mentioned horizontal wheel stiffness control method when executing the computer program.

[0045] In order to solve the above technical problems, the present invention provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, the above-mentioned horizontal wheel stiffness control method is implemented.

[0046] It can be seen that the method of the present invention establishes a force analysis model of a straddle-type monorail vehicle, determines the target guiding torque, inputs the target guiding torque into the force analysis model, and obtains the tire radial force; obtains the tire radial compression under the target guiding torque, and determines the horizontal wheel target stiffness based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression; determines the stiffness-tire pressure correlation model, inputs the horizontal wheel target stiffness into the stiffness-tire pressure correlation model to obtain the horizontal wheel target tire pressure; adjusts the horizontal wheel tire pressure to the horizontal wheel target tire pressure, so that the running wheel stiffness reaches the horizontal wheel target stiffness. The method of the present invention achieves stiffness control of the horizontal wheel by adjusting the tire pressure of the horizontal wheel, so that the straddle-type monorail vehicle has better anti-overturning ability when passing through a curve. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0048] Figure 1 A flow chart of a horizontal wheel stiffness control method provided by an embodiment of the present invention;

[0049] Figure 2 An exemplary diagram of a bogie provided by an embodiment of the present invention;

[0050] Figure 3 A schematic cross-sectional view of a horizontal wheel provided in an embodiment of the present invention;

[0051] Figure 4 This is a structural block diagram of a horizontal wheel stiffness control device provided by an embodiment of the present invention.

[0052] The following are the descriptions of the reference numerals:

[0053] 1-front bogie; 2-rear bogie; 3-intake valve; 4-vent; 5-exhaust valve; 6-air storage chamber; 7-sealing ring; 8-horizontal wheel tire; 9-main shaft; 10-rim; 11-tire inner cavity; 12-explosion-proof support body; 13-explosion-proof valve. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] The lateral spacing of the running wheels of straddle-type monorail vehicles is very small, and the vehicle's anti-rollover ability is guaranteed by the contact between the guide wheels and the stabilizing wheels and the side of the track. If the radial force of the horizontal wheel is 0, the vehicle's anti-rollover ability will be insufficient when passing through a curved line, and the vehicle will then deviate from the track beam, causing a major safety accident. If the preload of the horizontal wheel is increased, the vehicle's anti-rolling ability will be enhanced, and the vehicle's curve passing performance will also be improved. However, this will directly increase the wear of the running wheels and the horizontal tire surface, affecting the service life of the rubber wheel.

[0056] Secondly, if the vehicle speed is too high, the vehicle is subjected to excessive centrifugal force, the tilt angle is larger, and the lateral displacement of the horizontal wheel will be greater than the pre-compression of the horizontal wheel, and the horizontal wheel will leave the track surface. Therefore, it is necessary to actively adjust the stiffness of the horizontal wheel to achieve better rollover stability.

[0057] The bending radius of the straddle-type monorail line is small, and the excitation spectrum of the track beam is larger than that of the railway. Therefore, it is easy to cause impact excitation, which in turn causes the structural parts of the bogie to over-yield and be damaged or even destroyed. At the same time, the wheels have a strong impact on the beam surface, causing damage to the beam surface. In addition, when encountering icy and snowy weather, monorail vehicles frequently slip. By adjusting the tire pressure of the running wheels, increasing the contact area and improving the grip, the occurrence of slipping incidents can be effectively avoided. Other anti-skid measures, such as tire anti-skid chains, are prone to damage the beam surface or finger plates.

[0058] The following combination Figure 1 , Figure 1A flowchart of a horizontal wheel stiffness control method provided by an embodiment of the present invention, the method may include:

[0059] S101: establishing a force analysis model of a straddle-type monorail vehicle, determining a target steering torque, inputting the target steering torque into the force analysis model, and obtaining a tire radial force.

[0060] According to existing relevant research, the evaluation indicators of vehicle curve passability mainly include horizontal wheel radial force, rollover coefficient, tire force scalar and steering torque. Taking the steering torque as an example, when the vehicle is subjected to a large unbalanced centrifugal acceleration, a force analysis model can be established for the straddle-type monorail vehicle.

[0061] The expression of the force analysis model in this embodiment is related to the number of horizontal wheels (guide wheels and stabilizing wheels) and running wheels of the straddle-type monorail vehicle. In practical applications, the force analysis model can be determined based on the number of various types of tires of the straddle-type monorail vehicle. In the example, each straddle-type monorail vehicle can have four guide wheels, two stabilizing wheels and four running wheels. Then, the force analysis model of the straddle-type monorail vehicle in this embodiment can be:

[0062]

[0063] In the formula, F i is the horizontal wheel radial force, i is 1-6, F1, F2, F3 and F4 are the guide wheel radial forces of the front left, front right, rear right and rear left guide wheels respectively, F5 and F6 are the stabilizing wheel radial forces of the left and right stabilizing wheels respectively, m is the vehicle mass, g is the gravitational acceleration, α is the superelevation angle of the track beam, β is the vehicle body roll angle, v is the vehicle speed, R is the curve radius, g c is the centrifugal acceleration, F7 and F8 are the longitudinal forces of the two springs, A is the longitudinal spacing of the guide wheels, B is the lateral spacing of the two springs, C is the wheelbase, N is the distance between the tire contact center line and the track beam center, M is the guiding torque on the bogie, F9 and F 9c F is the side force of the two coaxial running wheels on the first axis, 10 and F 10c is the side deflection force of the coaxial running wheel on the second axis, F 11 and F 11c is the sideways force of the two running wheels on the same side of the bogie, F 12 and F 12c It is the running wheel side force of the two running wheels on the other side of the bogie.

[0064] Since the running wheel cornering force is positively correlated with the running wheel radial force, this embodiment can determine the positive correlation coefficient of each running wheel cornering force, and multiply the running wheel cornering force obtained by the force analysis model by the corresponding positive correlation coefficient to obtain the corresponding running wheel radial force.

[0065] This embodiment can determine the target steering torque, input the target steering torque into the force analysis model, and obtain the tire radial force.

[0066] S102: Obtain the radial compression of the tire under the target steering torque, and determine the target stiffness of the horizontal wheel based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression.

[0067] S103: Determine a stiffness-tire pressure correlation model, and input the horizontal wheel target stiffness into the stiffness-tire pressure correlation model to obtain the horizontal wheel target tire pressure.

[0068] Since the radial force (load force) of the tire is determined by the air pressure inside the tire, the present embodiment can establish a relationship between the tire pressure, the radial force of the tire, the amount of tire compression, and the tire stiffness, as shown below:

[0069] (PP a )v λ =cons;

[0070] F=(PP a )S = Kx;

[0071] Furthermore, the expression of the stiffness-tire pressure correlation model can be obtained by differentiating the tire compression:

[0072]

[0073] Where P is tire pressure, P a is atmospheric pressure, v is vehicle speed, λ is polytropic index, F is tire radial force, K is tire stiffness, x is tire radial compression, S is tire volume, cons is a constant, and Z is effective load area.

[0074] In the effective load area change rate, the effective load area and tire compression are linearly related:

[0075]

[0076] Where Z is the effective load area, Z0 is the initial effective load area, Q is the linear coefficient, and x is the radial compression of the tire.

[0077] Furthermore, the expression of the stiffness-tire pressure correlation model can be rewritten as:

[0078]

[0079] The expression of tire radial force can be:

[0080]

[0081] In this embodiment, the radial compression of the tire under the target steering torque can be obtained, and the horizontal wheel target stiffness is determined based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression. This embodiment does not limit the method for obtaining the tire radial compression, which can generally be obtained through sensor collection and conversion.

[0082] In this embodiment, the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression can be substituted into the above formula to obtain the target stiffness of the horizontal wheel that needs to be adjusted under the target steering torque. The target tire pressure of the horizontal wheel can be obtained by inputting the target stiffness of the horizontal wheel into the determined stiffness-tire pressure correlation model.

[0083] S104: Adjust the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel, so that the stiffness of the running wheel reaches the target stiffness of the horizontal wheel.

[0084] This embodiment can adjust the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel so that the stiffness of the running wheel reaches the target stiffness of the horizontal wheel. This embodiment does not limit the specific method of tire pressure adjustment. Generally, the target tire pressure of the horizontal wheel can be sent to the tire pressure adjustment system so that the tire pressure adjustment system adjusts the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel. The tire pressure adjustment system in this embodiment can be connected to each tire of the straddle-type monorail vehicle to control the inflation and deflation of the tires.

[0085] In this embodiment, in order to ensure the anti-overturning capability of the straddle-type monorail vehicle, multiple constraint conditions may be set during the horizontal force stiffness control process, and each constraint condition may be set individually or in coordination.

[0086] First, in this embodiment, constraints can be set to constrain the radial force of each tire to avoid the situation where the radial force of the tire exceeds the load range under the target steering torque. In this embodiment, the specific method of constraining the radial force of the tire is not limited. Generally, the measured radial force of the tire can be determined based on the tire compression amount, and the equivalent radial force can be determined based on the theoretical radial force of the tire; the radial force threshold can be determined based on the maximum radial force of the guide wheel, the maximum radial force of the stabilizing wheel and the maximum radial force of the running wheel; if the equivalent radial force is greater than the radial force threshold, the target steering torque is re-determined.

[0087] This embodiment can determine the tire measured radial force based on the tire compression. The tire radial force mentioned in this embodiment is a theoretical force determined by a force analysis model. The tire measured radial force is the tire measured radial force converted from the collected tire compression. The specific conversion process can be substituted into the relationship between tire pressure, tire radial force, tire compression and tire stiffness for conversion.

[0088] In this embodiment, the equivalent radial force can be determined based on the theoretical radial force of the tire. The equivalent radial force in this embodiment is the equivalent radial force after the radial forces measured by each tire are synthesized. The general expression of the equivalent radial force can be:

[0089] F all =F w +F d +2F z ;

[0090] In the formula, F all is the equivalent radial force, also known as the wear equivalent force, F w The total radial force measured by the stabilizing wheel, F d The guide wheel measures the total radial force, F z The running wheel measures the sum of the radial forces.

[0091] In this embodiment, the equivalent radial force can be limited so that the equivalent radial force is less than or equal to the radial force threshold, as shown in the following formula:

[0092] F all ≤F wmax +F dmax +2F zmax ;

[0093] In the formula, F wmax is the maximum radial force of the stabilizing wheel, F dmax is the maximum radial force of the guide wheel, F zmax is the maximum radial force of the running wheel.

[0094] Furthermore, in this embodiment, a horizontal wheel radial force-vehicle speed-curve radius correlation model can be established to constrain the horizontal wheel radial force, and the vehicle speed and curve radius are input into the horizontal wheel radial force-vehicle speed-curve radius correlation model to obtain a reference horizontal wheel radial force output by the model; if the horizontal wheel radial force is not equal to the corresponding reference horizontal wheel radial force, the target steering torque can be re-determined;

[0095] The expression of the horizontal wheel radial force-vehicle speed-curve radius correlation model is:

[0096] F jz-i =μ i1 +μ i2 *v 2 +μi3 *R;

[0097] In the formula, F jz-i is the reference horizontal wheel radial force of the i-th horizontal wheel, μ i1 , μ i2 and μ i3 is the constant coefficient of the i-th horizontal wheel, v is the vehicle speed, R is the curve radius when the vehicle passes through the curve, and i is 1-6 in the example.

[0098] Furthermore, the present embodiment may constrain the bogie offset angle. Specifically, the present embodiment may establish a bogie offset angle constraint model. If the bogie offset angle does not satisfy the bogie offset angle constraint model, the target steering torque is re-determined.

[0099] The expression of the bogie offset angle constraint model is:

[0100]

[0101] Where θ is the bogie offset angle, is the vehicle angular acceleration, and t is the vehicle running time when passing through the curve.

[0102] Finally, this embodiment can constrain the set target steering torque. Specifically, this embodiment can establish a steering torque constraint model to determine the root mean square of the steering torque when the curve passes through. If the root mean square of the steering torque does not satisfy the steering torque constraint model, the target steering torque is re-determined.

[0103] The expression of the guiding moment constraint model is:

[0104]

[0105] Where M rms is the root mean square of the guiding torque, M max is the maximum guiding torque, I z is the moment of inertia, A is the longitudinal distance between the guide wheels, R is the curve radius, and v is the vehicle speed.

[0106] according to Figure 2 As shown, when the method of the present invention is actually applied, the front bogie (1) and the rear bogie (2) are located in a curved section. To enable the vehicle to have good curve passing performance, the tire pressure of the front left and rear right guide wheels of the front bogie must be increased to increase the radial force. The tire pressure of the front right and rear left guide wheels is reduced to reduce the radial force. In this way, when the vehicle turns left, the radial force on the four guide wheels of the front bogie will form a guiding torque that causes the vehicle to rotate along the direction of track travel; the rear bogie is turning right relative to the front bogie, so the radial force of the four guide wheels should form a guiding torque in the opposite direction to the front bogie.

[0107] In order to adapt to the tire pressure regulation system, the cross-sectional diagram of the horizontal wheel in this embodiment can be as follows: Figure 3 As shown, the inlet valve 3 and the exhaust valve 5 are mounted on the main shaft 9, and there is a vent hole 4 inside the main shaft, which leads to the air storage chamber 6. There are sealing rings 7 above and below the air storage chamber to prevent gas leakage. The air storage chamber has a through hole that passes through the rim 10 and reaches the tire cavity 11 of the horizontal wheel tire 8. If a tire blows out, it can be inflated to the explosion-proof support body 12 to achieve emergency driving. At the same time, the explosion-proof valve 13 will automatically block the air path to the tire.

[0108] Furthermore, when the vehicle is traveling on ice, lowering the tire pressure can improve the traction performance of the tire. Considering that under the same load, lower tire pressure can increase the contact area between the tire and the ice surface, thereby increasing the friction coefficient of the contact surface. In this embodiment, the ice passability of the straddle-type monorail vehicle can be improved by adjusting the tire pressure of the running wheels, thereby improving the anti-skid performance.

[0109] Specifically, the present embodiment can obtain the running wheel rotation speed, and determine the vehicle slip rate based on the running wheel rotation speed; if the slip rate is greater than the slip rate threshold, determine the running wheel target tire pressure that is lower than the running wheel current tire pressure; send the running wheel target tire pressure to the tire pressure regulation system, so that the tire pressure regulation system adjusts the running wheel tire pressure to the running wheel target tire pressure; determine the running wheel friction coefficient based on the running wheel target tire pressure, and determine the running wheel adhesion torque based on the running wheel friction coefficient, the running wheel radial force in the tire radial force, and the running wheel tire radius; send a torque command to the running wheel motor controller to control the running wheel drive torque to be less than the running wheel adhesion torque.

[0110] In this embodiment, the vehicle slip rate can be determined by the rotation speed of the running wheels. If the vehicle slip rate is greater than the slip rate threshold, the tire pressure of the running wheels can be reduced to increase the friction coefficient between the tire and the contact surface.

[0111] Different tire pressures, loads, speeds and other factors will affect the friction coefficient of the tire. The relative sliding speed of the contact surface between the tire and the ice surface increases, which reduces the friction coefficient of the contact surface. At this time, the tire-ice adhesion ability decreases, and the ice surface cannot provide high traction. Under a large load, the contact area between the tire and the ice surface increases, making the dry friction area between the tire and the ice surface larger. Under low-speed conditions, the higher the load, the greater the traction and torque. Reducing the internal pressure of the tire can improve the tire's traction performance. Considering that under the same load, a lower tire pressure can increase the tire-ice contact area, thereby increasing the friction coefficient of the contact surface.

[0112] The correlation model between the running tire pressure and the running wheel friction coefficient can be shown as follows:

[0113] μ m =f(P z ,v,E);

[0114] In the formula, μ m is the friction coefficient of the running wheel, P z is the running tire pressure, v is the vehicle speed, E is the comprehensive factor of tire rubber material, aspect ratio and tire width, and f is the related function.

[0115] In this embodiment, the target tire pressure of the running wheel can be substituted into the above formula to obtain the running wheel friction coefficient under the target tire pressure of the running wheel. Further, the running wheel adhesion torque is determined based on the running wheel friction coefficient, the running wheel radial force in the tire radial force, and the running wheel tire radius, which can be specifically calculated by the following formula:

[0116] N j =μ m-j F j r;

[0117] Where N j is the running wheel adhesion torque of the jth running wheel, μ m-j is the friction coefficient of the jth running wheel, F j The radial force of the running wheel of the jth running wheel.

[0118] This embodiment can send a torque instruction to the motor controller of the running wheel to control the running wheel driving torque to be smaller than the running wheel adhesion torque. Specifically, the torque instruction can be directly sent to the motor controller of each running wheel through the CAN (Controller Area Network) bus to make the motor reduce the driving torque output and make the driving torque smaller than the adhesion torque of each running wheel, thereby achieving the purpose of traction torque control.

[0119] Based on the above embodiments, the present invention adjusts the tire pressure of the horizontal wheels to achieve stiffness control of the horizontal wheels, so that the straddle-type monorail vehicle has better anti-overturning ability when passing through a curve.

[0120] The following combination Figure 4 , FIG. 1 is a structural block diagram of a horizontal wheel stiffness control device provided by an embodiment of the present invention, and the device may include:

[0121] The first module 100 is used to establish a force analysis model of a straddle-type monorail vehicle, determine a target steering torque, input the target steering torque into the force analysis model, and obtain a tire radial force;

[0122] The second module 200 is used to obtain the radial compression of the tire under the target steering torque, and determine the horizontal wheel target stiffness based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression;

[0123] The third module 300 is used to determine a stiffness-tire pressure correlation model, and input the horizontal wheel target stiffness into the stiffness-tire pressure correlation model to obtain the horizontal wheel target tire pressure;

[0124] The fourth module 400 is used to adjust the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel so that the stiffness of the running wheel reaches the target stiffness of the horizontal wheel.

[0125] Based on the above embodiments, the method of the present invention adjusts the tire pressure of the horizontal wheels to achieve stiffness control of the horizontal wheels, so that the straddle-type monorail vehicle has better anti-overturning ability when passing through a curve.

[0126] Based on the above embodiment, the device may further include:

[0127] A fifth module is used to obtain a running wheel speed, and determine a vehicle slip rate based on the running wheel speed;

[0128] A sixth module is used to determine a target tire pressure of the running wheel that is lower than the current tire pressure of the running wheel if the slip rate is greater than the slip rate threshold;

[0129] A seventh module is used to send the target tire pressure of the running wheel to a tire pressure regulating system, so that the tire pressure regulating system regulates the tire pressure of the running wheel to the target tire pressure of the running wheel;

[0130] An eighth module is used to determine a running wheel friction coefficient based on the running wheel target tire pressure, and determine a running wheel adhesion torque based on the running wheel friction coefficient, the running wheel radial force in the tire radial force, and the running wheel tire radius;

[0131] The ninth module is used to send a torque instruction to the motor controller of the running wheel to control the driving torque of the running wheel to be smaller than the adhesion torque of the running wheel.

[0132] Based on the above embodiments, the device may further include:

[0133] A tenth module is used to determine a tire measured radial force based on the tire compression amount, and determine an equivalent radial force based on the tire measured radial force;

[0134] An eleventh module is used to determine a radial force threshold based on the maximum radial force of the guide wheel, the maximum radial force of the stabilizing wheel, and the maximum radial force of the running wheel;

[0135] The twelfth module is used to redetermine the target steering torque if the equivalent radial force is greater than the radial force threshold.

[0136] Based on the above embodiments, the device may further include:

[0137] The thirteenth module is used to establish a horizontal wheel radial force-vehicle speed-curve radius correlation model, input the vehicle speed and curve radius into the horizontal wheel radial force-vehicle speed-curve radius correlation model, and obtain a reference horizontal wheel radial force output by the model;

[0138] A fourteenth module is used to redetermine the target steering torque if the horizontal wheel radial force is not equal to the reference horizontal wheel radial force;

[0139] The expression of the horizontal wheel radial force-vehicle speed-curve radius correlation model is:

[0140] F jz-i =μ i1 +μ i2 *v 2 +μ i3 *R;

[0141] In the formula, F jz-i is the reference horizontal wheel radial force of the i-th horizontal wheel, μ i1 , μ i2 and μ i3 is the constant coefficient of the i-th horizontal wheel, v is the vehicle speed, and R is the curve radius.

[0142] Based on the above embodiments, the device may further include:

[0143] A fifteenth module is used to establish a bogie offset angle constraint model, and if the bogie offset angle does not satisfy the bogie offset angle constraint model, the target steering torque is re-determined;

[0144] The expression of the bogie offset angle constraint model is:

[0145]

[0146] Where θ is the bogie offset angle, is the vehicle angular acceleration, and t is the vehicle running time when passing through the curve.

[0147] Based on the above embodiments, the device may further include:

[0148] A sixteenth module is used to establish a guiding torque constraint model to determine the root mean square of the guiding torque when passing through a curve, and if the root mean square of the guiding torque does not satisfy the guiding torque constraint model, then the target guiding torque is re-determined;

[0149] The expression of the guiding moment constraint model is:

[0150]

[0151] Where Mrms is the root mean square of the guiding torque, M max is the maximum guiding torque, I z is the moment of inertia, A is the longitudinal distance between the guide wheels, R is the curve radius, and v is the vehicle speed.

[0152] Based on the above embodiments, the fourth module 400 may include:

[0153] The first unit is used to send the horizontal wheel target tire pressure to a tire pressure regulation system, so that the tire pressure regulation system regulates the tire pressure of the horizontal wheel to the horizontal wheel target tire pressure.

[0154] Based on the above embodiments, the present invention further provides a horizontal wheel stiffness control device, which may include a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the steps provided in the above embodiments may be implemented. Of course, the device may also include various necessary network interfaces, power supplies, and other components.

[0155] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by an execution terminal or a processor, the method provided in the embodiment of the present invention can be implemented; the storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0156] In this article, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

Claims

1. A horizontal wheel stiffness control method, characterized in that: include: Establishing a force analysis model of a straddle-type monorail vehicle, determining a target steering torque, inputting the target steering torque into the force analysis model, and obtaining a tire radial force; Acquire the radial compression of the tire under the target steering torque, and determine the horizontal wheel target stiffness based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression; Determining a stiffness-tire pressure correlation model, and inputting the horizontal wheel target stiffness into the stiffness-tire pressure correlation model to obtain the horizontal wheel target tire pressure; The tire pressure of the horizontal wheel is adjusted to the horizontal wheel target tire pressure so that the stiffness of the horizontal wheel reaches the horizontal wheel target stiffness.

2. The horizontal wheel stiffness control method according to claim 1, characterized in that: Also includes: Acquiring a running wheel speed, and determining a vehicle slip rate based on the running wheel speed; If the slip ratio is greater than the slip ratio threshold, determining a running wheel target tire pressure that is lower than a running wheel current tire pressure; Sending the running wheel target tire pressure to a tire pressure regulating system so that the tire pressure regulating system regulates the tire pressure of the running wheel to the running wheel target tire pressure; Determine the running wheel friction coefficient based on the running wheel target tire pressure, and determine the running wheel adhesion torque based on the running wheel friction coefficient, the running wheel radial force in the tire radial force, and the running wheel tire radius; A torque command is sent to the motor controller of the running wheel to control the running wheel driving torque to be smaller than the running wheel adhesion torque.

3. The horizontal wheel stiffness control method according to claim 1, characterized in that: Also includes: Determine a tire measured radial force based on the tire compression, and determine an equivalent radial force based on the tire measured radial force; Determine the radial force threshold based on the maximum radial force of the guide wheel, the maximum radial force of the stabilizing wheel and the maximum radial force of the running wheel; If the equivalent radial force is greater than the radial force threshold, the target steering torque is re-determined.

4. The horizontal wheel stiffness control method according to claim 1, characterized in that: Also includes: Establishing a horizontal wheel radial force-vehicle speed-curve radius correlation model, inputting the vehicle speed and curve radius into the horizontal wheel radial force-vehicle speed-curve radius correlation model, and obtaining a reference horizontal wheel radial force output by the model; If the horizontal wheel radial force is not equal to the reference horizontal wheel radial force, redetermining the target steering torque; The expression of the horizontal wheel radial force-vehicle speed-curve radius correlation model is: F jz-i =μ i1 +m i2 *v 2 +m i3 *R; In the formula, F jz-i is the reference horizontal wheel radial force of the i-th horizontal wheel, μ i1 , μ i2 and μ i3 is the constant coefficient of the i-th horizontal wheel, v is the vehicle speed, and R is the curve radius.

5. The horizontal wheel stiffness control method according to claim 1, characterized in that: Also includes: Establishing a bogie offset angle constraint model, and if the bogie offset angle does not satisfy the bogie offset angle constraint model, re-determining the target steering torque; The expression of the bogie offset angle constraint model is: Where θ is the bogie offset angle, is the vehicle angular acceleration, and t is the vehicle running time when passing the curve.

6. The horizontal wheel stiffness control method according to claim 1, characterized in that: Also includes: Establishing a guiding torque constraint model, determining the root mean square of the guiding torque when the curve passes through, and re-determining the target guiding torque if the root mean square of the guiding torque does not satisfy the guiding torque constraint model; The expression of the guiding moment constraint model is: Where M rms is the root mean square of the guiding torque, M max is the maximum guiding torque, I z is the moment of inertia, A is the longitudinal distance between the guide wheels, R is the curve radius, and v is the vehicle speed.

7. The horizontal wheel stiffness control method according to claim 1, characterized in that: Adjusting the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel includes: The horizontal wheel target tire pressure is sent to a tire pressure regulation system, so that the tire pressure regulation system regulates the tire pressure of the horizontal wheel to the horizontal wheel target tire pressure.

8. A horizontal wheel stiffness control device, characterized in that: include: The first module is used to establish a force analysis model of a straddle-type monorail vehicle, determine a target steering torque, input the target steering torque into the force analysis model, and obtain a tire radial force; The second module is used to obtain the radial compression of the tire under the target steering torque, and determine the horizontal wheel target stiffness based on the horizontal wheel radial force in the tire radial force and the horizontal wheel radial compression in the tire radial compression; A third module is used to determine a stiffness-tire pressure correlation model, and input the horizontal wheel target stiffness into the stiffness-tire pressure correlation model to obtain the horizontal wheel target tire pressure; The fourth module is used to adjust the tire pressure of the horizontal wheel to the target tire pressure of the horizontal wheel so that the stiffness of the horizontal wheel reaches the target stiffness of the horizontal wheel.

9. A horizontal wheel stiffness control device, characterized in that: include: Memory, for storing computer programs; A processor, configured to implement the horizontal wheel stiffness control method as claimed in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, the horizontal wheel stiffness control method according to any one of claims 1 to 7 is implemented.

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