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

Abstract

The application 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 gearboxes. The method comprises the following steps: collecting gearbox related data; calculating the total equivalent rotational inertia of the synchronizing part of a countershaft based on gearbox structure parameters, establishing the relationship between the braking torque of a countershaft brake and the rotational angular acceleration of the countershaft, establishing the relationship between the braking torque generated by the friction plate of the countershaft brake and the air cylinder pressure of the brake, establishing the relationship between the internal pressure of the air cylinder and the air intake and exhaust of the air cylinder, establishing the gas flow rate calculation formula in the air intake and exhaust process of the air cylinder, and establishing the relationship between the gas flow rate in the air cylinder and the real-time internal pressure of the air cylinder; the simultaneous equations are used to calculate the specific state of the countershaft brake at any moment during the working process, and the piston thrust and the braking torque of the brake are controlled by adjusting the volume of the air cylinder and the time between air intake and air exhaust. The application realizes accurate control of the braking performance of the brake, and improves driving safety and comfort.

Description

Technical Field

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

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

[0003] The vast majority of current commercial vehicle AMT transmissions feature a brake installed on the countershaft. This adjusts the countershaft speed to align the input and output speeds, enabling smooth shifting. The countershaft brake plays a crucial role in this process. Most brakes utilize a pneumatically controlled structure, controlling the movement of the cylinder piston through intake boost and exhaust pressure relief, compressing the brake pads and friction plates to achieve friction braking, thereby varying the countershaft speed. During the intake and exhaust processes, cylinder pressure changes dynamically. Since many design processes use static peak values ​​for theoretical calculations, deviations between actual operating conditions and theoretical calculations can occur. This increases the workload during prototype testing and can lead to unexpected issues.

[0004] In order to improve the braking performance of a transmission brake, the present invention provides a transmission 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 its technical problems is:

[0007] In a first aspect, an embodiment of the present invention provides a method for calculating and controlling transmission air pressure, 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 countershaft synchronized parts based on the gearbox structural parameters, and establishing a relationship between the braking torque of the countershaft brake and the countershaft rotational angular acceleration when the countershaft brake is in operation;

[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 structural 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: Based on the principles of aerodynamics, a calculation formula for the gas flow rate during the cylinder intake and exhaust processes 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 steps S2 to S5, calculates the specific state of the secondary shaft brake at any time during operation, 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 rotational angular acceleration when the secondary shaft brake is in operation is:

[0016] The brake working process meets:

[0017]

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

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

[0020]

[0021] in, is the equivalent moment of inertia of the synchronized parts:

[0022]

[0023] in, 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 countershaft brake, uses an area integration method to establish a relationship between the braking torque generated by the countershaft brake friction plate and the brake cylinder pressure, includes the following steps:

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

[0026]

[0027] in, 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]

[0029] Where, is the friction coefficient between the brake pads, is the contact surface pressure of the brake friction pad;

[0030] Brake friction pad contact surface pressure for:

[0031]

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

[0033]

[0034] in, is the brake return spring stiffness coefficient, L is the cylinder piston movement distance;

[0035] The simultaneous equations give the following relationship for the countershaft brake torque:

[0036]

[0037] Where 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 introduces a thermodynamic equation based on the mechanical structural parameters of the cylinder 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 is:

[0040]

[0041] Differential equation for cylinder volume change:

[0042]

[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; is the temperature in Kelvin;

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

[0047]

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

[0049] As a possible implementation of this embodiment, step S5, based on aerodynamic principles, establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust processes, and substitutes the experimentally fitted resistance coefficient of the gas flow rate 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] Where 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 vehicle input air source pressure; and is the resistance coefficient during the intake and exhaust process, 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 operation includes:

[0057] The following parameters of the countershaft brake during operation are calculated: cylinder volume, cylinder piston cross-sectional area, cylinder inlet and exhaust port cross-sectional areas, 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 transmission air pressure calculation and control device, comprising:

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

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

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

[0062] The module for establishing the relationship between pressure and intake and exhaust is used 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 by introducing thermodynamic equations;

[0063] The flow rate and pressure relationship establishment module is used to establish a calculation formula for the gas flow rate during the cylinder intake and exhaust process based on the principles of aerodynamics. 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;

[0064] The countershaft brake state calculation module is used to calculate the specific state of the countershaft brake at any time during its operation by using simultaneous equations. The piston thrust and brake torque are controlled 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 rotational angular acceleration when the secondary shaft brake is in operation is:

[0067] The brake working process meets:

[0068]

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

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

[0071]

[0072] in, is the equivalent moment of inertia of the synchronized parts:

[0073]

[0074] in, The moment of inertia of the target synchronized part along the rotation axis, its value can be obtained through 3D design software.

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

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

[0077]

[0078] in, 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]

[0080] Where, is the friction coefficient between the brake pads, is the contact surface pressure of the brake friction pad;

[0081] Brake friction pad contact surface pressure for:

[0082]

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

[0084]

[0085] in, is the brake return spring stiffness coefficient, L is the cylinder piston movement distance;

[0086] The simultaneous equations give the following relationship for the countershaft brake torque:

[0087]

[0088] Where 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 module for establishing the relationship between pressure and intake and exhaust is based on the mechanical structure parameters of the cylinder and introduces thermodynamic equations to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder. The specific process is as follows:

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

[0091]

[0092] Differential equation for cylinder volume change:

[0093]

[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; is the temperature in Kelvin;

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

[0098]

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

[0100] As a possible implementation of this embodiment, the flow rate and pressure relationship establishment module establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust process based on aerodynamic principles, and substitutes the drag coefficient of the gas flow rate obtained through 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. 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] Where 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 vehicle input air source pressure; and is the resistance coefficient during the intake and exhaust process, 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 inlet and exhaust 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. 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 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 having a computer program stored thereon, which, when executed by a processor, executes the steps of any of the above-mentioned transmission air pressure calculation and control methods.

[0110] The beneficial effects of the technical solutions of the embodiments of the present invention are as follows:

[0111] A method for calculating and controlling transmission air pressure according to a technical solution of an embodiment of the present invention includes the following steps: Step S1, collecting relevant transmission data, including transmission structural parameters, 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 transmission structural parameters, and establishing a relationship between the braking torque of the countershaft brake during operation and the countershaft rotational angular acceleration; Step S3, establishing a relationship between the braking torque generated by the countershaft brake friction pad and the brake cylinder pressure using an area integration method based on the countershaft brake structural parameters; In step S4, based on the mechanical structural parameters of the cylinder, thermodynamic equations are introduced to establish the relationship between the internal pressure of the cylinder and the cylinder intake and exhaust. In step S5, based on the principles 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 experimentally fitted and substituted into the calculation formula to establish the relationship between the gas flow rate in the cylinder and the real-time internal pressure of the cylinder. In step S6, the relationship formulas in steps S2 to S5 are combined to calculate the specific state of the countershaft brake at any time during operation, and the piston thrust and brake torque are controlled 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 conditions of the automatic transmission under various operating conditions, thereby achieving precise 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 transmission air pressure according to an exemplary embodiment;

[0113] Figure 2 is a schematic structural diagram of a countershaft brake according to an exemplary embodiment;

[0114] Figure 3 The figure is a schematic structural 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 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, an embodiment of the present invention provides a method for calculating and controlling transmission air pressure, comprising 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 countershaft synchronized parts based on the gearbox structural parameters, and establishing a relationship between the braking torque of the countershaft brake and the countershaft rotational angular acceleration when the countershaft brake is in operation;

[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 structural 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: Based on the principles of aerodynamics, a calculation formula for the gas flow rate during the cylinder intake and exhaust processes 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 steps S2 to S5, calculates the specific state of the secondary shaft brake at any time during operation, 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 countershaft end ( Figure 2 The braking function is achieved by charging the piston on the intake side of the cylinder to press the friction plate. After the braking time is completed according to the control strategy, the air is exhausted. 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, disengaging from the brake plate, and the braking torque disappears.

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

[0126] The brake working process meets:

[0127]

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

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

[0130]

[0131] in, is the equivalent moment of inertia of the synchronized parts:

[0132]

[0133] in, The moment of inertia of the target synchronized part along the rotation axis, 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 countershaft brake, uses an area integration method to establish a relationship between the braking torque generated by the countershaft brake friction plate and the brake cylinder pressure, includes the following steps:

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

[0136]

[0137] in, 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]

[0139] Where, is the friction coefficient between the brake pads, is the contact surface pressure of the brake friction pad;

[0140] Brake friction pad contact surface pressure for:

[0141]

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

[0143]

[0144] in, is the brake return spring stiffness coefficient, L is the cylinder piston movement distance;

[0145] The simultaneous equations give the following relationship for the countershaft brake torque:

[0146]

[0147] Where 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 introduces a thermodynamic equation based on the mechanical structural parameters of the cylinder 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 is:

[0150]

[0151] Differential equation for cylinder volume change:

[0152]

[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). is the temperature in Kelvin;

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

[0157]

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

[0159] As a possible implementation of this embodiment, step S5, based on aerodynamic principles, establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust processes, and substitutes the experimentally fitted resistance coefficient of the gas flow rate 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] Where v is the gas flow rate; 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 vehicle input air source pressure; and is the resistance coefficient during the intake and exhaust process, which can be obtained by fitting the 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 operation includes:

[0167] The following parameters of the countershaft brake during operation are calculated: cylinder volume, cylinder piston cross-sectional area, cylinder inlet and exhaust port cross-sectional areas, 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 transmission air pressure calculation and control device, comprising:

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

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

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

[0173] The module for establishing the relationship between pressure and intake and exhaust is used 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 by introducing thermodynamic equations;

[0174] The flow rate and pressure relationship establishment module is used to establish a calculation formula for the gas flow rate during the cylinder intake and exhaust process based on the principles of aerodynamics. 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;

[0175] The countershaft brake state calculation module is used to calculate the specific state of the countershaft brake at any time during its operation by using simultaneous equations. The piston thrust and brake torque are controlled 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 rotational angular acceleration when the secondary shaft brake is in operation is:

[0178] The brake working process meets:

[0179]

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

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

[0182]

[0183] in, is the equivalent moment of inertia of the synchronized parts:

[0184]

[0185] in, The moment of inertia of the target synchronized part along the rotation axis, its value can be obtained through 3D design software.

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

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

[0188]

[0189] in, 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]

[0191] Where, is the friction coefficient between the brake pads, is the contact surface pressure of the brake friction pad;

[0192] Brake friction pad contact surface pressure for:

[0193]

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

[0195]

[0196] in, is the brake return spring stiffness coefficient, L is the cylinder piston movement distance;

[0197] The simultaneous equations give the following relationship for the countershaft brake torque:

[0198]

[0199] Where 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 module for establishing the relationship between pressure and intake and exhaust is based on the mechanical structure parameters of the cylinder and introduces thermodynamic equations to establish the relationship between the internal pressure of the cylinder and the intake and exhaust of the cylinder. The specific process is as follows:

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

[0202]

[0203] Differential equation for cylinder volume change:

[0204]

[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). is the temperature in Kelvin;

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

[0209]

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

[0211] As a possible implementation of this embodiment, the flow rate and pressure relationship establishment module establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust process based on aerodynamic principles, and substitutes the drag coefficient of the gas flow rate obtained through 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. 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] Where v is the gas flow rate; 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 vehicle input air source pressure; and is the resistance coefficient during the intake and exhaust process, which can be obtained by fitting the 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 inlet and exhaust hole cross-sectional area, cylinder valve opening time, brake friction surface friction coefficient and brake return spring stiffness.

[0219] Analysis of the above calculation model clearly shows that the main parameters affecting brake performance are: cylinder volume V, cylinder piston cross-sectional area S, cylinder inlet and exhaust port cross-sectional areas s, cylinder valve opening time t, brake friction surface friction coefficient u, and brake return spring stiffness k. By adjusting these parameters, the present invention can achieve precise control of brake performance.

[0220] An embodiment of the present invention provides an electronic device, including 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 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, it can execute the above-mentioned transmission air pressure calculation and control method.

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

[0223] In some embodiments, the electronic device may also include a touch screen for displaying a graphical user interface (e.g., an application launch interface) and receiving user operations on the graphical user interface (e.g., application launch operations). Specifically, the touch screen may include a display panel and a touch panel. The display panel may be configured in the form of an LCD (Liquid Crystal Display), an OLED (Organic Light-Emitting Diode), or other devices. The touch panel can detect contact or non-contact operations performed by the user on or near it and generate pre-set operation instructions. For example, the user can use a finger, a stylus, or any other suitable object, or an attachment, on or near the touch panel to perform operations. Furthermore, the touch panel may include two components: a touch detection device and a touch controller. The touch detection device detects the user's touch position and posture, detects signals generated by the touch operation, and transmits the signals to the touch controller. The touch controller receives the touch information from the touch detection device, converts it into information that can be processed by the processor, and then transmits it to the processor. The touch controller can also receive and execute commands from the processor. In addition, the touch panel can be implemented using 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. Furthermore, 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 transmits it to the processor to determine the user input, and then the processor provides a 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 above-mentioned application startup method, an embodiment of the present invention further provides a storage medium on which a computer program is stored. When the computer program is run by a processor, the steps of any of the above-mentioned transmission air pressure calculation and control methods are executed.

[0225] The startup device of the application provided in the embodiment of the present application can be specific hardware on the device or software or firmware installed on the device. The implementation principle and technical effects of the device provided in the embodiment of the present application are the same as those of the aforementioned method embodiment. For the sake of brief description, for any part not mentioned in the device embodiment, reference can be made to the corresponding content in the aforementioned method embodiment. Those skilled in the art can clearly understand that for the convenience and brevity 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 take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0227] In the embodiments provided in this 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 interface, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

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

[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 block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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 produce 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 that can direct a computer or other programmable data processing device to work 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 The 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 operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function 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 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 by the scope of protection of the claims of the present invention.

Claims

1. A method for calculating and controlling transmission air pressure, 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 countershaft synchronized parts based on the gearbox structural parameters, and establishing a relationship between the braking torque of the countershaft brake and the countershaft rotational angular acceleration when the countershaft brake is in operation; 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; Step S4, based on the mechanical structural 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: Based on the principles of aerodynamics, a calculation formula for the gas flow rate during the cylinder intake and exhaust processes 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 steps S2 to S5, calculates the specific state of the secondary shaft brake at any time during operation, and controls the piston thrust and brake torque by adjusting the cylinder volume and the time between intake and exhaust.

2. The transmission air pressure calculation and control method 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 transmission air pressure calculation and control method according to claim 2, characterized in that: The relationship between the braking torque and the angular acceleration of the countershaft when the countershaft brake is working is: The brake working process meets: Wherein, T is the working torque of the countershaft brake, and α is the angular acceleration of the countershaft; is the total equivalent moment of inertia of the synchronized parts of the gearbox countershaft, and its calculation satisfies: in, is the equivalent moment of inertia of the synchronized parts: in, The moment of inertia of the target synchronized part along the rotation axis.

4. The transmission air pressure calculation and control method according to claim 3, characterized in that: The step S3, based on the structural parameters of the countershaft brake, uses the area integration method to establish the relationship between the braking torque generated by the countershaft brake friction plate and the brake cylinder pressure, includes the following steps: For a single friction surface of the brake, the braking torque generated satisfies the equation: in, 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: Where, is the friction coefficient between the brake pads, is the contact surface pressure of the brake friction pad; Brake friction pad contact surface pressure for: in, is the pressure inside the cylinder, S is the cross-sectional area of ​​the cylinder piston, is the brake friction area; is the force of the brake return spring on the piston, which satisfies the differential equation: in, is the brake return spring stiffness coefficient, L is the cylinder piston movement distance; The simultaneous equations give the following relationship for the countershaft brake torque: Where q is the number of brake friction surfaces and T is the working torque of the countershaft brake.

5. The transmission air pressure calculation and control method according to claim 4, characterized in that: The step S4, based on the mechanical structural 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 is: Differential equation for cylinder volume change: 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; is the temperature in Kelvin; The differential equation of the change of gas mass m inside the cylinder with time: in is the gas density inside the cylinder; t is the time.

6. The method for calculating and controlling transmission air pressure according to claim 5, characterized in that: Step S5, based on aerodynamic principles, establishes a calculation formula for the gas flow rate during the cylinder intake and exhaust processes, and substitutes the experimentally fitted resistance coefficient of the gas flow rate 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: The calculation formula for the cylinder intake process is: The calculation formula for the cylinder exhaust process is: Where 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 vehicle input air source pressure; and is the resistance coefficient during the intake and exhaust process, 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 transmission air pressure 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 are calculated: cylinder volume, cylinder piston cross-sectional area, cylinder inlet and exhaust port cross-sectional areas, 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 is used to collect relevant data of the gearbox, wherein the relevant data includes gearbox structural parameters, structural parameters of the countershaft brake and mechanical structural parameters of the cylinder; The torque and rotation angle relationship establishment module is used to calculate the total equivalent moment of inertia of the countershaft synchronized parts based on the gearbox structural parameters, and establish the relationship between the braking torque and the countershaft rotational angular acceleration when the countershaft brake is working; The torque and air pressure relationship establishment module is used to establish the relationship between the braking torque generated by the countershaft brake friction plate and the brake cylinder pressure based on the structural parameters of the countershaft brake using the area integration method; The module for establishing the relationship between pressure and intake and exhaust is used 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 by introducing thermodynamic equations; The flow rate and pressure relationship establishment module is used to establish a calculation formula for the gas flow rate during the cylinder intake and exhaust process based on the principles of aerodynamics. 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; The countershaft brake state calculation module is used to calculate the specific state of the countershaft brake at any time during its operation by using simultaneous equations. The piston thrust and brake torque are controlled by adjusting the cylinder volume and the time between intake and exhaust.

9. An electronic device, characterized in that: The electronic device comprises 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 and the memory communicate via 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 to 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 according to any one of claims 1 to 7.

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