Gearbox air pressure calculation and control method and device, electronic equipment and storage medium

Abstract

The invention discloses a gearbox air pressure calculation and control method and device, electronic equipment and a storage medium, and belongs to the technical field of automobile transmissions. The total equivalent rotational inertia of a countershaft synchronized part is calculated based on gearbox structure parameters, and the relation between the braking torque and the countershaft rotation angular acceleration when a countershaft brake works is established; establishing the relationship between the braking torque generated by the countershaft brake friction plate and the pressure intensity of the brake cylinder; establishing a relationship between cylinder internal pressure and cylinder intake and exhaust; establishing a gas flow rate calculation formula in the intake and exhaust process of the cylinder and a relationship between the gas flow rate in the cylinder and the real-time pressure in the cylinder; and the specific state of the countershaft brake at any moment in the working process is calculated according to the relational expression, and the thrust of the piston and the braking torque of the brake are controlled by adjusting the volume of the air cylinder and the time from air intake to air exhaust. Accurate control over the braking performance of the brake is achieved, and the driving safety and comfort are improved.

Description

Technical Field

[0001] The invention relates to a method, device, electronic equipment and storage medium for calculating and controlling air pressure of a gearbox, and belongs to the technical field of automobile gearboxes. Background Art

[0002] AMT (Automated Manual Transmission) is a transmission system that combines manual transmission and automatic transmission. Since its introduction, it has attracted much attention due to its relatively low cost.

[0003] Most commercial vehicle AMT transmissions now have brakes installed on the countershaft. By adjusting the countershaft speed to make the input and output speeds consistent, smooth shifting is achieved. The countershaft brake plays an extremely critical role in this process. Most of the brakes use a pneumatic control structure, which controls the movement of the cylinder piston through the intake boost and exhaust pressure relief of the brake cylinder, compresses the brake pads and friction pads, and achieves friction braking, thereby changing the countershaft speed. During the intake and exhaust process, the cylinder pressure is a dynamic change process. Since many design processes are theoretically calculated based on static peak values, the actual working state will deviate from the theoretical calculation, which will not only increase the workload in the prototype test phase, but also cause other unexpected problems.

[0004] In order to improve the braking performance of a gearbox brake, the present invention provides a gearbox air pressure calculation and control method, device, electronic equipment and storage medium. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a transmission air pressure calculation and control method, device, electronic equipment and storage medium, which can improve the braking performance of the transmission brake.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] In a first aspect, an embodiment of the present invention provides a method for calculating and controlling air pressure of a transmission, comprising the following steps:

[0008] Step S1, collecting relevant data of the gearbox, wherein the relevant data includes gearbox structural parameters, countershaft brake structural parameters and cylinder mechanical structural parameters;

[0009] Step S2, calculating the total equivalent moment of inertia of the synchronized parts of the countershaft based on the gearbox structural parameters, and establishing the relationship between the braking torque of the countershaft brake and the countershaft rotational angular acceleration when the countershaft brake is working;

[0010] Step S3, based on the structural parameters of the countershaft brake, using the area integration method to establish the relationship between the braking torque generated by the countershaft brake friction plate and the brake cylinder pressure;

[0011] Step S4, based on the mechanical structure parameters of the cylinder, a thermodynamic equation is introduced to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder;

[0012] Step S5, according to the principle of aerodynamics, a calculation formula for the gas flow rate during the cylinder intake and exhaust process is established, and the resistance coefficient of the gas flow rate is fitted experimentally and substituted into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder;

[0013] Step S6, combining the relationship equations in step S2 to step S5, calculates the specific state of the secondary shaft brake at any time during the working process, and controls the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust.

[0014] As a possible implementation of this embodiment, the mechanical structural parameters of the cylinder include the cylinder volume, the cylinder piston cross-sectional area, and the cylinder inlet and exhaust hole cross-sectional areas.

[0015] As a possible implementation of this embodiment, the relationship between the braking torque and the secondary shaft rotation angular acceleration when the secondary shaft brake is working is:

[0016] The brake working process meets:

[0017] T=J 总 α

[0018] Wherein, T is the working torque of the countershaft brake, and α is the angular acceleration of the countershaft rotation;

[0019] J 总 is the total equivalent moment of inertia of the synchronized parts of the gearbox countershaft, and its calculation satisfies:

[0020] J 总 =∑J i

[0021] Among them, J i is the equivalent moment of inertia of the synchronized parts:

[0022] J i =J′ i ×i 2

[0023] Among them, J′ i The moment of inertia of the target synchronized part along the rotation axis.

[0024] As a possible implementation of this embodiment, step S3, based on the structural parameters of the secondary shaft brake, uses the area integration method to establish the relationship between the braking torque generated by the secondary shaft brake friction plate and the brake cylinder pressure, includes the following steps:

[0025] For a single friction surface of the brake, the braking torque it generates satisfies the equation:

[0026] T = ∫dF f r

[0027] Among them, dF f The friction force on any force element on the friction surface is in the direction of the rotation tangent and its magnitude satisfies the following differential equation:

[0028] dF f =μP m rdrdθ

[0029] Where μ is the friction coefficient between the brake pad and the brake pad, P m is the contact surface pressure of the brake friction pad;

[0030] Brake friction pad contact surface pressure P m for:

[0031]

[0032] Among them, P1 is the pressure inside the cylinder, S is the cross-sectional area of ​​the cylinder piston, S m is the brake friction area; f is the force of the brake return spring on the piston, which satisfies the differential equation:

[0033] df=kdL

[0034] Among them, k is the brake return spring stiffness coefficient, and L is the cylinder piston movement distance;

[0035] By combining the equations, the relationship between the braking torque of the countershaft brake is obtained as follows:

[0036]

[0037] Among them, q is the number of brake friction surfaces, and T is the working torque of the countershaft brake.

[0038] As a possible implementation of this embodiment, step S4, based on the mechanical structure parameters of the cylinder, introduces a thermodynamic equation to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder, including:

[0039] The relationship between the thrust value F of the cylinder piston and the pressure change:

[0040] F=P1S

[0041] Differential equation for cylinder volume change:

[0042] dV=SdL

[0043] Introducing the thermodynamic equation PV = nRT, n = m / M, ρ = m / V, we can further obtain the differential equation for the change of the internal pressure of the cylinder with time as follows:

[0044]

[0045] Where n is the amount of gas in the cylinder; M is the unit molar mass of air; R is the thermodynamic constant; T0 is the Kelvin temperature;

[0046] The differential equation of the change of the gas mass m inside the cylinder with time:

[0047] dm=ρsvdt

[0048] Where ρ is the gas density inside the cylinder; t is the time.

[0049] As a possible implementation of this embodiment, step S5, based on the principle of aerodynamics, establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust process, and substitutes the drag coefficient of the gas flow rate obtained by experimental fitting into the calculation formula to establish a relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder, including:

[0050] The calculation formula for the cylinder intake process is:

[0051]

[0052] The calculation formula for the cylinder exhaust process is:

[0053]

[0054] Among them, v is the gas flow rate; a is the local sound speed; γ is the air specific heat ratio; P0 is the atmospheric pressure at normal temperature and pressure; P3 is the input air source pressure of the whole vehicle; A1 and A2 are the resistance coefficients during the intake and exhaust processes, which can be obtained by fitting the experimental data;

[0055] Through the calculation formula of the cylinder intake and exhaust process, the relationship between the exhaust velocity and the pressure in the cylinder during the intake and exhaust stages is obtained.

[0056] As a possible implementation of this embodiment, in step S6, calculating the specific state of the secondary shaft brake at any time during the working process includes:

[0057] The following parameters of the countershaft brake during operation were calculated: cylinder volume, cylinder piston cross-sectional area, cylinder air hole cross-sectional area, cylinder valve opening time, brake friction surface friction coefficient, and brake return spring stiffness.

[0058] In a second aspect, an embodiment of the present invention provides a gearbox air pressure calculation and control device, comprising:

[0059] A data acquisition module, used to acquire relevant data of the gearbox, wherein the relevant data includes structural parameters of the gearbox, structural parameters of the countershaft brake, and mechanical structural parameters of the cylinder;

[0060] A torque and rotation angle relationship establishment module is used to calculate the total equivalent rotational inertia of the countershaft synchronized parts based on the gearbox structural parameters, and to establish the relationship between the braking torque and the countershaft rotational angular acceleration when the countershaft brake is working;

[0061] A torque and air pressure relationship establishment module is used to establish the relationship between the braking torque generated by the friction plate of the secondary shaft brake and the brake cylinder pressure based on the structural parameters of the secondary shaft brake using the area integration method;

[0062] The module for establishing the relationship between pressure and intake and exhaust is used to introduce thermodynamic equations to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder based on the mechanical structure parameters of the cylinder;

[0063] The module for establishing the relationship between flow rate and pressure is used to establish the calculation formula for the gas flow rate during the cylinder intake and exhaust process according to the principle of aerodynamics, and substitute the resistance coefficient of the gas flow rate experimentally fitted into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder;

[0064] The secondary shaft brake state calculation module is used to calculate the specific state of the secondary shaft brake at any time during its operation by combining relationship equations, and to control the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust.

[0065] As a possible implementation of this embodiment, the mechanical structural parameters of the cylinder include the cylinder volume, the cylinder piston cross-sectional area, and the cylinder inlet and exhaust hole cross-sectional areas.

[0066] As a possible implementation of this embodiment, the relationship between the braking torque and the secondary shaft rotation angular acceleration when the secondary shaft brake is working is:

[0067] The brake working process meets:

[0068] T=J 总 α

[0069] Wherein, T is the working torque of the countershaft brake, and α is the angular acceleration of the countershaft rotation;

[0070] J 总 is the total equivalent moment of inertia of the synchronized parts of the gearbox countershaft, and its calculation satisfies:

[0071] J 总 =ΣJ i

[0072] Among them, J iis the equivalent moment of inertia of the synchronized parts:

[0073] J i =J′ i ×i 2

[0074] Among them, J′ i The target is the moment of inertia of the synchronized part along the rotation axis, and its value can be obtained through 3D design software.

[0075] As a possible implementation of this embodiment, the torque and air pressure relationship establishment module establishes the relationship between the braking torque generated by the friction plate of the secondary shaft brake and the brake cylinder pressure based on the structural parameters of the secondary shaft brake by using the area integration method. The specific process is:

[0076] For a single friction surface of the brake, the braking torque it generates satisfies the equation:

[0077] T = ∫dF f r

[0078] Among them, dF f The friction force on any force element on the friction surface is in the direction of the rotation tangent and its magnitude satisfies the following differential equation:

[0079] dF f =μP m rdrdθ

[0080] Where μ is the friction coefficient between the brake pad and the brake pad, P m is the contact surface pressure of the brake friction pad;

[0081] Brake friction pad contact surface pressure P m for:

[0082]

[0083] Among them, P1 is the pressure inside the cylinder, S is the cross-sectional area of ​​the cylinder piston, S m is the brake friction area; f is the force of the brake return spring on the piston, which satisfies the differential equation:

[0084] df=kdL

[0085] Among them, k is the brake return spring stiffness coefficient, and L is the cylinder piston movement distance;

[0086] By combining the equations, the relationship between the braking torque of the countershaft brake is obtained as follows:

[0087]

[0088] Among them, q is the number of brake friction surfaces, and T is the working torque of the countershaft brake.

[0089] As a possible implementation of this embodiment, the pressure and intake and exhaust relationship establishment module introduces thermodynamic equations based on the mechanical structure parameters of the cylinder to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder. The specific process is:

[0090] The relationship between the thrust value F of the cylinder piston and the pressure change:

[0091] F=P1S

[0092] Differential equation for cylinder volume change:

[0093] dV=SdL

[0094] Introducing the thermodynamic equation PV = nRT, n = m / M, ρ = m / V, we can further obtain the differential equation for the change of the internal pressure of the cylinder with time as follows:

[0095]

[0096] Where n is the amount of gas in the cylinder; M is the unit molar mass of air; R is the thermodynamic constant; T0 is the Kelvin temperature;

[0097] The differential equation of the change of the gas mass m inside the cylinder with time:

[0098] dm=ρsvdt

[0099] Where ρ is the gas density inside the cylinder; t is the time.

[0100] As a possible implementation of this embodiment, the flow velocity and pressure relationship establishment module establishes a gas flow velocity calculation formula during the cylinder intake and exhaust process according to the aerodynamic principle, and substitutes the resistance coefficient of the gas flow velocity obtained by experimental fitting into the calculation formula to establish the relationship between the gas flow velocity in the cylinder and the real-time pressure inside the cylinder. The specific process is as follows:

[0101] The calculation formula for the cylinder intake process is:

[0102]

[0103] The calculation formula for the cylinder exhaust process is:

[0104]

[0105] Among them, v is the gas flow rate; a is the local sound speed; γ is the air specific heat ratio; P0 is the atmospheric pressure at normal temperature and pressure; P3 is the input air source pressure of the whole vehicle; A1 and A2 are the resistance coefficients during the intake and exhaust processes, which can be obtained by fitting the experimental data;

[0106] Through the calculation formula of the cylinder intake and exhaust process, the relationship between the exhaust velocity and the pressure in the cylinder during the intake and exhaust stages is obtained.

[0107] As a possible implementation method of this embodiment, the secondary shaft brake state calculation module calculates the specific state of the secondary shaft brake at any time during its operation, including the following parameters: cylinder volume, cylinder piston cross-sectional area, cylinder air hole cross-sectional area, cylinder valve opening time, brake friction surface friction coefficient and brake return spring stiffness.

[0108] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the memory via the bus, and the processor executes the machine-readable instructions to perform the steps of any of the above-mentioned transmission air pressure calculation and control methods.

[0109] In a fourth aspect, an embodiment of the present invention provides a storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned transmission air pressure calculation and control methods are executed.

[0110] The beneficial effects of the technical solution of the embodiment of the present invention are as follows:

[0111] A method for calculating and controlling air pressure of a gearbox according to the technical solution of an embodiment of the present invention comprises the following steps: step S1, collecting relevant data of the gearbox, wherein the relevant data comprises structural parameters of the gearbox, structural parameters of a countershaft brake and mechanical structural parameters of a cylinder; step S2, calculating the total equivalent moment of inertia of the countershaft synchronized parts based on the structural parameters of the gearbox, and establishing the relationship between the braking torque of the countershaft brake and the angular acceleration of the countershaft when the countershaft brake is working; step S3, establishing the relationship between the braking torque generated by the friction plate of the countershaft brake and the brake cylinder pressure by using an area integration method based on the structural parameters of the countershaft brake; Step S4, based on the mechanical structure parameters of the cylinder, introduce the thermodynamic equation to establish the relationship between the internal pressure of the cylinder and the cylinder intake and exhaust; Step S5, according to the principle of aerodynamics, establish the gas flow rate calculation formula during the cylinder intake and exhaust process, and substitute the resistance coefficient of the gas flow rate into the calculation formula through experimental fitting, and establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder; Step S6, combine the relationship formulas in steps S2 to S5, calculate the specific state of the secondary shaft brake at any time during the working process, and control the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust. The present invention provides an innovative and practical method for calculating and controlling the internal pressure of an automatic transmission, which can effectively simulate and predict the internal pressure distribution and gas flow of the automatic transmission under various working conditions, thereby realizing accurate control of the brake performance and improving driving safety and comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Figure 1 is a flow chart of a method for calculating and controlling air pressure of a transmission according to an exemplary embodiment;

[0113] Figure 2 is a schematic diagram of a secondary shaft brake structure according to an exemplary embodiment;

[0114] Figure 3 It is a structural schematic diagram of a transmission air pressure calculation and control device according to an exemplary embodiment. DETAILED DESCRIPTION

[0115] In order to more clearly illustrate the technical features of the solution of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0116] like Figure 1 As shown, a method for calculating and controlling air pressure of a transmission provided by an embodiment of the present invention comprises the following steps:

[0117] Step S1, collecting relevant data of the gearbox, wherein the relevant data includes gearbox structural parameters, countershaft brake structural parameters and cylinder mechanical structural parameters;

[0118] Step S2, calculating the total equivalent moment of inertia of the synchronized parts of the countershaft based on the gearbox structural parameters, and establishing the relationship between the braking torque of the countershaft brake and the countershaft rotational angular acceleration when the countershaft brake is working;

[0119] Step S3, based on the structural parameters of the countershaft brake, using the area integration method to establish the relationship between the braking torque generated by the countershaft brake friction plate and the brake cylinder pressure;

[0120] Step S4, based on the mechanical structure parameters of the cylinder, a thermodynamic equation is introduced to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder;

[0121] Step S5, according to the principle of aerodynamics, a calculation formula for the gas flow rate during the cylinder intake and exhaust process is established, and the resistance coefficient of the gas flow rate is fitted experimentally and substituted into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder;

[0122] Step S6, combining the relationship equations in step S2 to step S5, calculates the specific state of the secondary shaft brake at any time during the working process, and controls the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust.

[0123] As a possible implementation of this embodiment, the mechanical structural parameters of the cylinder include the cylinder volume, the cylinder piston cross-sectional area, and the cylinder inlet and exhaust hole cross-sectional areas.

[0124] The structure of the countershaft brake is as follows: Figure 2 As shown, the friction plate and the secondary shaft end ( Figure 2 The braking function is achieved by inflating the piston on the air intake side of the cylinder to press the friction plate. After the braking time is completed according to the control strategy, exhaust begins. As the thrust of the cylinder on the piston decreases, the braking torque will decrease. After the thrust drops to a critical value, the piston will be reset by the return spring, disengage from the brake pad, and the braking torque disappears.

[0125] As a possible implementation of this embodiment, the relationship between the braking torque and the secondary shaft rotation angular acceleration when the secondary shaft brake is working is:

[0126] The brake working process meets:

[0127] T=J 总 α

[0128] Wherein, T is the working torque of the countershaft brake, and α is the angular acceleration of the countershaft rotation;

[0129] J 总 is the total equivalent moment of inertia of the synchronized parts of the gearbox countershaft, and its calculation satisfies:

[0130] J总 =ΣJ i

[0131] Among them, J i is the equivalent moment of inertia of the synchronized parts:

[0132] J i =J′ i ×i 2

[0133] Among them, J′ i The target is the moment of inertia of the synchronized part along the rotation axis, and its value can be obtained through 3D design software.

[0134] As a possible implementation of this embodiment, step S3, based on the structural parameters of the secondary shaft brake, uses the area integration method to establish the relationship between the braking torque generated by the secondary shaft brake friction plate and the brake cylinder pressure, includes the following steps:

[0135] For a single friction surface of the brake, the braking torque it generates satisfies the equation:

[0136] T = ∫dF f r

[0137] Among them, dF f The friction force on any force element on the friction surface is in the direction of the rotation tangent and its magnitude satisfies the following differential equation:

[0138] dF f =μP m rdrdθ

[0139] Where μ is the friction coefficient between the brake pad and the brake pad, P m is the contact surface pressure of the brake friction pad;

[0140] Brake friction pad contact surface pressure P m for:

[0141]

[0142] Among them, P1 is the pressure inside the cylinder, S is the cross-sectional area of ​​the cylinder piston, S m is the brake friction area; f is the force of the brake return spring on the piston, which satisfies the differential equation:

[0143] df=kdL

[0144] Among them, k is the brake return spring stiffness coefficient, and L is the cylinder piston movement distance;

[0145] By combining the equations, the relationship between the braking torque of the countershaft brake is obtained as follows:

[0146]

[0147] Among them, q is the number of brake friction surfaces, and T is the working torque of the countershaft brake.

[0148] As a possible implementation of this embodiment, step S4, based on the mechanical structure parameters of the cylinder, introduces a thermodynamic equation to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder, including:

[0149] The relationship between the thrust value F of the cylinder piston and the pressure change:

[0150] F=P1S

[0151] Differential equation for cylinder volume change:

[0152] dV=SdL

[0153] Introducing the thermodynamic equation PV = nRT, n = m / M, ρ = m / V, we can further obtain the differential equation for the change of the internal pressure of the cylinder with time as follows:

[0154]

[0155] Where n is the amount of gas in the cylinder; M is the unit molar mass of air, which is generally 28.96 (g / mol); R is the thermodynamic constant, which is 8.314 (Pa·m / mol / k); T0 is the Kelvin temperature;

[0156] The differential equation of the change of the gas mass m inside the cylinder with time:

[0157] dm=ρsvdt

[0158] Where ρ is the gas density inside the cylinder; t is the time.

[0159] As a possible implementation of this embodiment, step S5, based on the principle of aerodynamics, establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust process, and substitutes the drag coefficient of the gas flow rate obtained by experimental fitting into the calculation formula to establish a relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder, including:

[0160] The calculation formula for the cylinder intake process is:

[0161]

[0162] The calculation formula for the cylinder exhaust process is:

[0163]

[0164] Wherein, v is the gas velocity; a is the local sound speed; γ is the air specific heat ratio, which is usually 1.4; P0 is the atmospheric pressure at normal temperature and pressure; P3 is the input air source pressure of the vehicle; A1 and A2 are the resistance coefficients during the intake and exhaust processes, which can be obtained by fitting experimental data;

[0165] Through the calculation formula of the cylinder intake and exhaust process, the relationship between the exhaust velocity and the pressure in the cylinder during the intake and exhaust stages is obtained.

[0166] As a possible implementation of this embodiment, in step S6, calculating the specific state of the secondary shaft brake at any time during the working process includes:

[0167] The following parameters of the countershaft brake during operation were calculated: cylinder volume, cylinder piston cross-sectional area, cylinder air hole cross-sectional area, cylinder valve opening time, brake friction surface friction coefficient, and brake return spring stiffness.

[0168] In the specific implementation process, the cross-sectional area of ​​the piston and the cross-sectional area of ​​the exhaust hole are limited and difficult to adjust. The present invention achieves precise control of the piston thrust and the brake torque by adjusting the cylinder volume and the time between intake and exhaust.

[0169] like Figure 3 As shown, an embodiment of the present invention provides a gearbox air pressure calculation and control device, comprising:

[0170] A data acquisition module, used to acquire relevant data of the gearbox, wherein the relevant data includes structural parameters of the gearbox, structural parameters of the countershaft brake, and mechanical structural parameters of the cylinder;

[0171] A torque and rotation angle relationship establishment module is used to calculate the total equivalent rotational inertia of the countershaft synchronized parts based on the gearbox structural parameters, and to establish the relationship between the braking torque and the countershaft rotational angular acceleration when the countershaft brake is working;

[0172] A torque and air pressure relationship establishment module is used to establish the relationship between the braking torque generated by the friction plate of the secondary shaft brake and the brake cylinder pressure based on the structural parameters of the secondary shaft brake using the area integration method;

[0173] The module for establishing the relationship between pressure and intake and exhaust is used to introduce thermodynamic equations to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder based on the mechanical structure parameters of the cylinder;

[0174] The module for establishing the relationship between flow rate and pressure is used to establish the calculation formula for the gas flow rate during the cylinder intake and exhaust process according to the principle of aerodynamics, and substitute the resistance coefficient of the gas flow rate experimentally fitted into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder;

[0175] The secondary shaft brake state calculation module is used to calculate the specific state of the secondary shaft brake at any time during its operation by combining relationship equations, and to control the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust.

[0176] As a possible implementation of this embodiment, the mechanical structural parameters of the cylinder include the cylinder volume, the cylinder piston cross-sectional area, and the cylinder inlet and exhaust hole cross-sectional areas.

[0177] As a possible implementation of this embodiment, the relationship between the braking torque and the secondary shaft rotation angular acceleration when the secondary shaft brake is working is:

[0178] The brake working process meets:

[0179] T=J 总 α

[0180] Wherein, T is the working torque of the countershaft brake, and α is the angular acceleration of the countershaft rotation;

[0181] J 总 is the total equivalent moment of inertia of the synchronized parts of the gearbox countershaft, and its calculation satisfies:

[0182] J 总 =ΣJ i

[0183] Among them, J i is the equivalent moment of inertia of the synchronized parts:

[0184] J i =J′ i ×i 2

[0185] Among them, J′ i The target is the moment of inertia of the synchronized part along the rotation axis, and its value can be obtained through 3D design software.

[0186] As a possible implementation of this embodiment, the torque and air pressure relationship establishment module establishes the relationship between the braking torque generated by the friction plate of the secondary shaft brake and the brake cylinder pressure based on the structural parameters of the secondary shaft brake by using the area integration method. The specific process is:

[0187] For a single friction surface of the brake, the braking torque it generates satisfies the equation:

[0188] T = ∫dF f r

[0189] Among them, dF f The friction force on any force element on the friction surface is in the direction of the rotation tangent and its magnitude satisfies the following differential equation:

[0190] dF f =μP m rdrdθ

[0191] Where μ is the friction coefficient between the brake pad and the brake pad, P m is the contact surface pressure of the brake friction pad;

[0192] Brake friction pad contact surface pressure P m for:

[0193]

[0194] Among them, P1 is the pressure inside the cylinder, S is the cross-sectional area of ​​the cylinder piston, S m is the brake friction area; f is the force of the brake return spring on the piston, which satisfies the differential equation:

[0195] df=kdL

[0196] Among them, k is the brake return spring stiffness coefficient, and L is the cylinder piston movement distance;

[0197] By combining the equations, the relationship between the braking torque of the countershaft brake is as follows:

[0198]

[0199] Among them, q is the number of brake friction surfaces, and T is the working torque of the countershaft brake.

[0200] As a possible implementation of this embodiment, the pressure and intake and exhaust relationship establishment module introduces thermodynamic equations based on the mechanical structure parameters of the cylinder to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder. The specific process is:

[0201] The relationship between the thrust value F of the cylinder piston and the pressure change:

[0202] F=P1S

[0203] Differential equation for cylinder volume change:

[0204] dV=SdL

[0205] Introducing the thermodynamic equation PV = nRT, n = m / M, ρ = m / V, we can further obtain the differential equation for the change of the internal pressure of the cylinder with time as follows:

[0206]

[0207] Where n is the amount of gas in the cylinder; M is the unit molar mass of air, which is generally 28.96 (g / mol); R is the thermodynamic constant, which is 8.314 (Pa·m / mol / k); T0 is the Kelvin temperature;

[0208] The differential equation of the change of the gas mass m inside the cylinder with time:

[0209] dm=ρsvdt

[0210] Where ρ is the gas density inside the cylinder; t is time.

[0211] As a possible implementation of this embodiment, the flow velocity and pressure relationship establishment module establishes a gas flow velocity calculation formula during the cylinder intake and exhaust process according to the aerodynamic principle, and substitutes the resistance coefficient of the gas flow velocity obtained by experimental fitting into the calculation formula to establish the relationship between the gas flow velocity in the cylinder and the real-time pressure inside the cylinder. The specific process is as follows:

[0212] The calculation formula for the cylinder intake process is:

[0213]

[0214] The calculation formula for the cylinder exhaust process is:

[0215]

[0216] Wherein, v is the gas velocity; a is the local sound speed; γ is the air specific heat ratio, which is usually 1.4; P0 is the atmospheric pressure at normal temperature and pressure; P3 is the input air source pressure of the vehicle; A1 and A2 are the resistance coefficients during the intake and exhaust processes, which can be obtained by fitting experimental data;

[0217] Through the calculation formula of the cylinder intake and exhaust process, the relationship between the exhaust velocity and the pressure in the cylinder during the intake and exhaust stages is obtained.

[0218] As a possible implementation method of this embodiment, the secondary shaft brake state calculation module calculates the specific state of the secondary shaft brake at any time during its operation, including the following parameters: cylinder volume, cylinder piston cross-sectional area, cylinder air hole cross-sectional area, cylinder valve opening time, brake friction surface friction coefficient and brake return spring stiffness.

[0219] Through the analysis of the above calculation model, it is obvious that the main parameters affecting the brake performance are: cylinder volume V, cylinder piston cross-sectional area S, cylinder air hole cross-sectional area s, cylinder valve opening time t, brake friction surface friction coefficient u, brake return spring stiffness k. The present invention can achieve precise control of the brake performance by adjusting the above parameters.

[0220] An embodiment of the present invention provides an electronic device, including a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus, and the processor executes the machine-readable instructions to perform the steps of any of the above-mentioned transmission air pressure calculation and control methods.

[0221] Specifically, the above-mentioned memory and processor can be general-purpose memory and processor, which are not specifically limited here. When the processor runs the computer program stored in the memory, the above-mentioned transmission air pressure calculation and control method can be executed.

[0222] Those skilled in the art will appreciate that the structure of the electronic device does not limit the electronic device and may include more or fewer components than shown in the figure, or combine or split certain components, or arrange the components differently.

[0223] In some embodiments, the electronic device may also include a touch screen that can be used to display a graphical user interface (e.g., a startup interface of an application) and receive user operations on the graphical user interface (e.g., startup operations on an application). The specific touch screen may include a display panel and a touch panel. The display panel may be configured in the form of LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode), etc. The touch panel may collect the user's contact or non-contact operations on or near it, and generate pre-set operation instructions, for example, the user uses any suitable object such as a finger, stylus, or accessories on or near the touch panel. In addition, the touch panel may include two parts: a touch detection device and a touch controller. Among them, the touch detection device detects the user's touch orientation and posture, detects the signal brought by the touch operation, and transmits the signal to the touch controller; the touch controller receives the touch information from the touch detection device, converts it into information that the processor can process, and then sends it to the processor, and can receive and execute commands from the processor. In addition, the touch panel can be implemented by various types such as resistive, capacitive, infrared and surface acoustic wave, and any technology developed in the future can also be used to implement the touch panel. Further, the touch panel can cover the display panel, and the user can operate on or near the touch panel covered on the display panel according to the graphical user interface displayed on the display panel. After the touch panel detects the operation on or near it, it is transmitted to the processor to determine the user input, and then the processor provides corresponding visual output on the display panel in response to the user input. In addition, the touch panel and the display panel can be implemented as two independent components or integrated.

[0224] Corresponding to the method for starting the above-mentioned application, an embodiment of the present invention further provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned transmission air pressure calculation and control methods are executed.

[0225] The application startup device provided in the embodiment of the present application can be specific hardware on the device or software or firmware installed on the device. The device provided in the embodiment of the present application, its implementation principle and the technical effect produced are the same as those in the aforementioned method embodiment. For the sake of brief description, the parts not mentioned in the device embodiment can refer to the corresponding contents in the aforementioned method embodiment. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above can all refer to the corresponding processes in the aforementioned method embodiment, and will not be repeated here.

[0226] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0227] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0228] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0229] In addition, each functional module in the embodiments provided in the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0230] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0231] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0232] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0233] 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 above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for calculating and controlling air pressure of a gearbox, characterized in that: The steps include: Step S1, collecting relevant data of the gearbox, wherein the relevant data includes gearbox structural parameters, countershaft brake structural parameters and cylinder mechanical structural parameters; Step S2, calculating the total equivalent moment of inertia of the synchronized parts of the countershaft based on the gearbox structural parameters, and establishing the relationship between the braking torque of the countershaft brake and the countershaft rotational angular acceleration when the countershaft brake is working; Step S3, based on the structural parameters of the countershaft brake, using the area integration method to establish the relationship between the braking torque generated by the friction plate of the countershaft brake and the brake cylinder pressure; Step S4, based on the mechanical structure parameters of the cylinder, a thermodynamic equation is introduced to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder; Step S5, according to the principle of aerodynamics, a calculation formula for the gas flow rate during the cylinder intake and exhaust process is established, and the resistance coefficient of the gas flow rate is fitted experimentally and substituted into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder; Step S6, combining the relationship equations in step S2 to step S5, calculates the specific state of the secondary shaft brake at any time during the working process, and controls the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust.

2. The method for calculating and controlling the air pressure of a transmission according to claim 1, characterized in that: The mechanical structural parameters of the cylinder include cylinder volume, cylinder piston cross-sectional area and cylinder inlet and exhaust hole cross-sectional areas.

3. The method for calculating and controlling the air pressure of a transmission according to claim 2, characterized in that: The relationship between the braking torque and the secondary shaft rotation angular acceleration when the secondary shaft brake is working is: The brake working process meets: T=J 总 a Wherein, T is the working torque of the countershaft brake, and α is the angular acceleration of the countershaft rotation; J 总 is the total equivalent moment of inertia of the synchronized parts of the gearbox countershaft, and its calculation satisfies: J 总 =∑J i Among them, J i is the equivalent moment of inertia of the synchronized parts: I i =J′ i ×i 2 Among them, J′ i The moment of inertia of the target synchronized part along the rotation axis.

4. The method for calculating and controlling the air pressure of a transmission according to claim 3, characterized in that: The step S3, based on the structural parameters of the secondary shaft brake, uses the area integration method to establish the relationship between the braking torque generated by the friction plate of the secondary shaft brake and the brake cylinder pressure, comprises the following steps: For a single friction surface of the brake, the braking torque it generates satisfies the equation: T=∫dF f r Among them, dF f The friction force on any force element on the friction surface is in the direction of the rotation tangent and its magnitude satisfies the following differential equation: dF f =μP m rdrdθ Where μ is the friction coefficient between the brake pad and the brake pad, P m is the contact surface pressure of the brake friction pad; Brake friction pad contact surface pressure P m for: Among them, P1 is the pressure inside the cylinder, S is the cross-sectional area of ​​the cylinder piston, S m is the brake friction area; f is the force of the brake return spring on the piston, which satisfies the differential equation: df=kdL Among them, k is the brake return spring stiffness coefficient, and L is the cylinder piston movement distance; By combining the equations, the relationship between the braking torque of the countershaft brake is obtained as follows: Among them, q is the number of brake friction surfaces, and T is the working torque of the countershaft brake.

5. The method for calculating and controlling the air pressure of a transmission according to claim 4, characterized in that: The step S4, based on the mechanical structure parameters of the cylinder, introduces a thermodynamic equation to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder, including: The relationship between the thrust value F of the cylinder piston and the pressure change: F=P1S Differential equation for cylinder volume change: dV=SdL Introducing the thermodynamic equation PV = nRT, n = m / M, ρ = m / V, we can further obtain the differential equation for the change of the internal pressure of the cylinder with time as follows: Where n is the amount of gas in the cylinder; M is the unit molar mass of air; R is the thermodynamic constant; T0 is the Kelvin temperature; The differential equation of the change of gas mass m inside the cylinder with time: dm=ρsvdt Where ρ is the gas density inside the cylinder; t is time.

6. The method for calculating and controlling the air pressure of a transmission according to claim 5, characterized in that: The step S5, according to the aerodynamic principle, establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust process, and substitutes the resistance coefficient of the gas flow rate obtained by experimental fitting into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder, including: The calculation formula for the cylinder intake process is: The calculation formula for the cylinder exhaust process is: Among them, v is the gas flow rate; a is the local sound speed; γ is the air specific heat ratio; P0 is the atmospheric pressure at normal temperature and pressure; P3 is the input air source pressure of the whole vehicle; A1 and A2 are the resistance coefficients during the intake and exhaust processes, which can be obtained by fitting the experimental data; Through the calculation formula of the cylinder intake and exhaust process, the relationship between the exhaust velocity and the pressure in the cylinder during the intake and exhaust stages is obtained.

7. The method for calculating and controlling the air pressure of a transmission according to any one of claims 1 to 6, characterized in that: In step S6, the specific state of the secondary shaft brake at any time during operation is calculated, including: The following parameters of the countershaft brake during operation were calculated: cylinder volume, cylinder piston cross-sectional area, cylinder air hole cross-sectional area, cylinder valve opening time, brake friction surface friction coefficient, and brake return spring stiffness.

8. A gearbox air pressure calculation and control device, characterized in that: include: A data acquisition module, used to acquire relevant data of the gearbox, wherein the relevant data includes structural parameters of the gearbox, structural parameters of the countershaft brake, and mechanical structural parameters of the cylinder; A torque and rotation angle relationship establishment module is used to calculate the total equivalent rotational inertia of the countershaft synchronized parts based on the gearbox structural parameters, and to establish the relationship between the braking torque and the countershaft rotational angular acceleration when the countershaft brake is working; A torque and air pressure relationship establishment module is used to establish the relationship between the braking torque generated by the friction plate of the secondary shaft brake and the brake cylinder pressure based on the structural parameters of the secondary shaft brake using the area integration method; The module for establishing the relationship between pressure and intake and exhaust is used to introduce thermodynamic equations to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder based on the mechanical structure parameters of the cylinder; The module for establishing the relationship between flow rate and pressure is used to establish the calculation formula for the gas flow rate during the cylinder intake and exhaust process according to the principle of aerodynamics, and substitute the resistance coefficient of the gas flow rate experimentally fitted into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time pressure inside the cylinder; The secondary shaft brake state calculation module is used to calculate the specific state of the secondary shaft brake at any time during its operation by combining relationship equations, and to control the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust.

9. An electronic device, characterized in that: It includes a processor, a memory and a bus, the memory stores machine-readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and the processor executes the machine-readable instructions to perform the steps of the transmission air pressure calculation and control method as described in any one of claims 1-7.

10. A storage medium, characterized in that: The storage medium stores a computer program, which, when executed by a processor, executes the steps of the transmission air pressure calculation and control method as described in any one of claims 1 to 7.

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