Decoupled Brake Pedal Simulation Device

Abstract

The present invention discloses a decoupled brake pedal simulation device, comprising: a brake pedal operating mechanism, a hydraulic cylinder connected to the brake pedal operating mechanism; the hydraulic cylinder is connected to a first high-speed switching valve and a second high-speed switching valve through an oil pipe, and the other end of the first high-speed switching valve is connected to a hydraulic pump; a simulator electronic control unit, a displacement sensor connected to the simulator electronic control unit, and the displacement sensor is connected to the brake pedal operating mechanism; a pressure sensor located in the hydraulic cylinder is connected to the simulator electronic control unit; the first high-speed switching valve and the second high-speed switching valve are connected to the simulator electronic control unit; stepping on the brake pedal operating mechanism pushes the piston of the hydraulic cylinder to displace, the displacement sensor outputs the measured displacement signal of the brake pedal to the simulator electronic control unit, and the pressure sensor outputs the measured pressure signal in the hydraulic cylinder to the simulator electronic control unit.

Description

Technical Field

[0001] This application belongs to the technical field of the electronic brake system for intelligent driving vehicles, and specifically refers to a decoupled brake pedal simulation device. Background Art

[0002] With the rapid popularization of electric vehicles, the number of electric vehicles in use has been increasing year by year. In the braking control system of electric vehicles, in the case of a lack of a vacuum source in electric vehicles, how to solve the realistic demand that users are already accustomed to the braking pedal feel of internal combustion locomotives is an urgent problem to be solved. And the current proposed solution is that the brake pedal operating mechanism and the brake actuator need to be decoupled, and the power transmission between the brake pedal operating mechanism and the brake actuator is separated, replaced by an electric wire. The original brake pedal is replaced by a brake pedal simulator. The brake pedal displacement sensor monitors the driver's braking intention, transmits the braking signal, converts the mechanical signal of the brake pedal into an electronic signal and transmits it to the corresponding electronic control unit and brake actuator, and the electronic control module is used to achieve the braking force and simulate the stepping feeling and feedback it to the driver according to a certain algorithm. There is no rigid connection or hydraulic connection between the brake pedal and the brake actuator.

[0003] The brake pedal simulator can not only provide a real driving experience for the driver, but also perform CAN bus testing to obtain real braking force - pedal travel data feedback. However, in the current existing technology, the decoupled brake pedal simulation device usually uses a series of double springs or a hydraulic cylinder or a rubber valve or a brake cylinder plus an accumulator product to simulate the pedal force of the brake pedal. The braking state provided by this solution still has a certain gap from the braking states of different working conditions such as slow braking, medium - intensity braking, and emergency braking of a real vehicle, thus reducing the driver's real experience. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the embodiments of this application provide a decoupled brake pedal simulation device that can adjust the linear feeling of the brake pedal feedback force according to requirements.

[0005] The embodiments of the present invention provide a decoupled brake pedal simulation device, and the decoupled brake pedal simulation device includes:

[0006] A brake pedal operating mechanism, a hydraulic cylinder connected to the brake pedal operating mechanism; the hydraulic cylinder is connected to a first high - speed switching valve and a second high - speed switching valve through an oil pipe, the other end of the first high - speed switching valve is connected to a hydraulic pump; the hydraulic pump is connected to a motor, and the motor drives the hydraulic pump; the other end of the first high - speed switching valve is also connected to a relief valve through an oil pipe, and the other end of the relief valve is connected to an accumulator;

[0007] The simulator electronic control unit, a displacement sensor connected to the simulator electronic control unit, and the displacement sensor is connected to the brake pedal operating mechanism; a pressure sensor located inside the hydraulic cylinder is connected to the simulator electronic control unit; the first high-speed switching valve and the second high-speed switching valve are connected to the simulator electronic control unit;

[0008] Stepping on the brake pedal operating mechanism pushes the piston of the hydraulic cylinder to displace, and the displacement sensor outputs the measured displacement signal of the brake pedal to the simulator electronic control unit, and the pressure sensor outputs the measured pressure signal inside the hydraulic cylinder to the simulator electronic control unit.

[0009] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, the brake pedal operating mechanism is a hanging stepping mechanism, the upper bracket of the brake pedal operating mechanism is installed on the front body panel, and the lower bracket of the brake pedal operating mechanism is installed on the vehicle body floor; the brake pedal arm of the brake pedal operating mechanism is connected to the hydraulic cylinder through a connecting fork.

[0010] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, the hydraulic cylinder includes a cylinder block, a damping elastic element arranged inside the cylinder block, a hydraulic cylinder piston arranged inside the cylinder block, and a sealing member is arranged on the outer circumferential surface of the hydraulic cylinder piston to seal the cylinder block;

[0011] One end of the hydraulic cylinder piston is connected to the brake pedal arm through the piston push rod, and the other end of the hydraulic cylinder piston is connected to the damping elastic element.

[0012] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, the damping elastic element includes but is not limited to a multi-stage spring, and the stiffness of the multi-stage spring is determined according to the maximum value of the brake pedal force.

[0013] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, the displacement sensor is installed on the piston push rod, and the displacement sensor converts the measured analog signal of the piston push rod displacement into a digital signal through an A / D converter and transmits it to the simulator electronic control unit.

[0014] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, the simulator electronic control unit calculates the reaction force value of the pedal according to the displacement of the brake pedal operating mechanism and the pressure of the hydraulic cylinder, and controls the pressure inside the hydraulic cylinder by adjusting the first high-speed switching valve and the second high-speed switching valve, and adjusts the output force of the hydraulic cylinder piston;

[0015] The pressure sensor outputs the real-time pressure value in the hydraulic cylinder to the simulator electronic control unit, and compares it with the required target pressure value to form a closed-loop PID control system with feedback, so as to control the pressure value in the hydraulic cylinder in real time.

[0016] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, calculating the reaction force value of the pedal includes: calculating the acting force F1 of the elastic element,

[0017] ;

[0018] wherein, S0 is the displacement of the piston push rod, K1 is the stiffness of the elastic element, i is the lever ratio of the brake pedal, and S is the stroke of the brake pedal.

[0019] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, calculating the thrust F2 of the piston push rod of the hydraulic cylinder includes:

[0020] Calculating the pressure P of the hydraulic cylinder;

[0021] ;

[0022] wherein, a and b are fitting coefficients, and V is the volume of the brake fluid;

[0023] Calculating the thrust F2 of the piston push rod of the hydraulic cylinder;

[0024] ;

[0025] wherein, A is the piston area of the hydraulic cylinder, and K2 is the elastic modulus of the brake fluid.

[0026] According to the decoupled brake pedal simulation device provided by the embodiment of the present invention, calculating the pedal force F and the pedal stroke S of the brake pedal includes:

[0027] ;

[0028] The electronic control unit of the simulator is built-in with a PID control algorithm and a fuzzy control algorithm for simulating the braking intention of the driver. The input parameters of the electronic control unit of the simulator are the brake pedal displacement and the brake pedal displacement change rate, and the control parameter of the electronic control unit of the simulator is the thrust of the piston push rod output by the hydraulic cylinder.

[0029] According to the decoupled brake pedal simulation device provided by the embodiments of the present invention, the first high-speed switching valve and the second high-speed switching valve control the oil pressure output through pulse width modulation technology; when the pulse is at a high level, the electromagnets in the first high-speed switching valve and the second high-speed switching valve are energized to generate suction force; when the pulse is at a low level, the electromagnets in the first high-speed switching valve and the second high-speed switching valve are de-energized, and the suction force generated by the electromagnets is zero;

[0030] By changing the duty cycle of the pulse width, the on-off time of the electromagnets inside the first high-speed switching valve and the second high-speed switching valve is changed, and the valve orifice sizes of the first high-speed switching valve and the second high-speed switching valve are changed to achieve the control of the pressure of the brake cylinder.

[0031] The beneficial effects of the present invention are as follows: The decoupled brake pedal simulation device provided by the embodiments of the present invention jointly simulates the brake pedal feedback force through the hydraulic components in the hydraulic cylinder and the damping elastic components arranged inside the hydraulic cylinder. The hydraulic components and the elastic components have good linear feedback force, and can well simulate the pedal feedback force of the brake pedal of a traditional internal combustion engine, conforming to the braking characteristics of the original internal combustion engine pedal. The electronic control unit of the simulator provided by the embodiments of the present invention presets the PID control algorithm and the fuzzy control algorithm for simulating the braking intention of the driver. The controller based on the fuzzy control algorithm can well simulate the driver's demand for braking force and better simulate the driver's braking intention. The PID control algorithm can accurately and real-time follow the pedal force preset by the target. During the actual use process of the decoupled brake pedal simulation device provided by the embodiments of the present invention, the brake pedal feedback force is appropriate and has good linearity. This device is simple to assemble and convenient to repair. Description of the Drawings

[0032] The following will make the technical solutions and other beneficial effects of the present application obvious by describing the specific embodiments of the present application in detail in conjunction with the drawings.

[0033] Figure 1 It is a structural schematic diagram of the decoupled brake pedal simulation device provided by this embodiment.

[0034] The reference numerals of each component in the figure are as follows: brake pedal operating mechanism 1, upper bracket 2, lower bracket 3, brake pedal arm 4, connecting fork 5, hydraulic cylinder 6, piston push rod 7, damping elastic component 8, displacement sensor 9, electronic control unit of the simulator 10, pressure sensor 11, oil pipe 12, first high-speed switching valve 13, second high-speed switching valve 14, hydraulic pump 15, motor 16, overflow valve 17 and accumulator 18. Detailed Embodiments

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0037] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0038] Figure 1 It is a schematic structural diagram of the decoupled brake pedal simulation device provided for this embodiment. As Figure 1 shown, the decoupled brake pedal simulation device includes: a brake pedal operating mechanism 1, and a hydraulic cylinder 6 connected to the brake pedal operating mechanism 1; the hydraulic cylinder 6 is connected to a first high-speed switching valve 13 and a second high-speed switching valve 14 through a pipeline 12, and the other end of the first high-speed switching valve 13 is connected to a hydraulic pump 15; the hydraulic pump 15 is connected to a motor 16, and the motor 16 drives the hydraulic pump 15; the other end of the first high-speed switching valve 13 is also connected to a relief valve 17 through the pipeline 12, and the other end of the relief valve 17 is connected to an accumulator 18;

[0039] The simulator electronic control unit 10, the displacement sensor 9 connected to the simulator electronic control unit 10, and the displacement sensor 9 is connected to the brake pedal operating mechanism 1; the pressure sensor 11 located in the hydraulic cylinder 6 is connected to the simulator electronic control unit 10; the first high-speed switching valve 13 and the second high-speed switching valve 14 are connected to the simulator electronic control unit 10;

[0040] Stepping on the brake pedal operating mechanism 1 drives the piston displacement of the hydraulic cylinder 6, the displacement sensor 9 outputs the measured displacement signal of the brake pedal operating mechanism 1 to the simulator electronic control unit 10, and the pressure sensor 11 outputs the measured pressure signal in the hydraulic cylinder 6 to the simulator electronic control unit 10.

[0041] As Figure 1 shown, in this embodiment, the brake pedal operating mechanism 1 is a hanging stepping mechanism, the brake pedal operating mechanism 1 is arranged according to the installation space of the intelligent cockpit, the upper bracket 2 of the brake pedal operating mechanism 1 is installed on the front body panel, and the lower bracket 3 of the brake pedal operating mechanism 1 is installed on the vehicle body floor. And the brake pedal operating mechanism 1 can be designed flexibly and diversely according to the structural changes of the driving cockpit to adapt to different intelligent cockpits. The stepping point of the brake pedal operating mechanism 1 also fully meets the requirements of vehicle ergonomics.

[0042] A point is taken on the brake pedal arm 4 of the brake pedal operating mechanism 1 to connect with the vehicle body, and the specific position is determined according to the lever ratio of the vehicle's brake pedal and the layout space of the hydraulic cylinder 6. The brake pedal arm 4 is connected to the hydraulic cylinder 6 through a connecting fork 5.

[0043] Specifically, the hydraulic cylinder 6 includes a damping elastic element 8 arranged inside the hydraulic cylinder 6. The brake pedal arm 4 is connected to the piston push rod 7 and is connected in series with the damping elastic element 8. The hydraulic cylinder 6 is provided with a piston, and a seal is arranged outside the piston to seal the cylinder block. The seal includes but is not limited to rubber seals, sealing washers, etc., and the seal can prevent impurities, dust, etc. from entering the cylinder block. One end of the hydraulic cylinder 6 is connected to the brake pedal arm 4 through the piston push rod 7, and the other end of the hydraulic cylinder 6 is connected to the damping elastic element 8.

[0044] Among them, the damping elastic element 8 includes but is not limited to multi-stage springs, and the stiffness of the multi-stage springs is determined according to the maximum value of the brake pedal force. The damping elastic element 8 of the multi-stage springs can ensure that the brake pedal feedback force is more linear.

[0045] In this embodiment, the series connection of the damping elastic element 8 is taken as an example for illustration. The damping elastic element 8 can also be installed in parallel or in series-parallel according to needs, which will not be elaborated here.

[0046] As Figure 1 shown, the displacement sensor 9 is installed on the piston push rod 7, and the displacement sensor 9 is communicatively connected to the simulator electronic control unit 10 through a data line. Stepping on the brake pedal of the brake pedal operating mechanism 1 drives the piston push rod 7 to displace. The displacement sensor 9 detects the displacement of the piston push rod 7, and the displacement sensor 9 converts the analog signal of the measured displacement of the piston push rod 7 into a digital signal through an A / D converter and transmits it to the simulator electronic control unit 10, and the simulator electronic control unit 10 processes the displacement of the piston push rod 7.

[0047] A pressure sensor 11 is arranged in the hydraulic cylinder 6. The pressure sensor 11 is communicatively connected to the simulator electronic control unit 10 through a data line and is connected to the first high-speed switching valve 13 and the second high-speed switching valve 14 through an oil pipe 12 at the same time. The pressure sensor 11 detects the pressure in the hydraulic cylinder 6 in real time and transmits it to the simulator electronic control unit 10. The pressure sensor 11 converts the analog signal of the measured pressure into a digital signal through an A / D converter and transmits it to the simulator electronic control unit 10, and the simulator electronic control unit 10 processes the pressure in the hydraulic cylinder 6.

[0048] As Figure 1 shown, the first high-speed switching valve 13 and the second high-speed switching valve 14 are communicated with the hydraulic cylinder 6 through an oil pipe 12, and the first high-speed switching valve 13 and the second high-speed switching valve 14 are communicatively connected to the simulator electronic control unit 10 through a data line. One end of the first high-speed switching valve 13 is communicated with the hydraulic pump 15 through an oil pipe 12, and the hydraulic pump 15 is driven by the motor 16. The other end of the first high-speed switching valve 13 is communicated with the overflow valve 17 through an oil pipe 12, and the other end of the overflow valve 17 is connected to the accumulator 18. The first high-speed switching valve 13 and the second high-speed switching valve 14 are powered by the simulator electronic control unit 10. In this embodiment, the supply voltage of the simulator electronic control unit 10 is 12V.

[0049] Specifically, the first high-speed switching valve 13 and the second high-speed switching valve 14 control the oil pressure output through PWM pulse width modulation technology; when the pulse is at a high level, the electromagnets in the first high-speed switching valve 13 and the second high-speed switching valve 14 are energized to generate suction; when the pulse is at a low level, the electromagnets in the first high-speed switching valve 13 and the second high-speed switching valve 14 are de-energized, and the suction generated by the electromagnets is zero.

[0050] By changing the duty ratio of the pulse width, the on-off time of the electromagnets inside the first high-speed switching valve 13 and the second high-speed switching valve 14 is changed, so as to change the orifice sizes of the first high-speed switching valve 13 and the second high-speed switching valve 14, and realize the control of the pressure of the brake cylinder.

[0051] Specifically, for the decoupled brake pedal simulation device provided by the embodiments of the present invention, the simulator electronic control unit 10 calculates the reaction force value of the pedal according to the displacement of the brake pedal operating mechanism 1 and the pressure of the hydraulic cylinder 6, and controls the pressure inside the hydraulic cylinder 6 by adjusting the first high-speed switching valve 13 and the second high-speed switching valve 14, and adjusts the output force of the piston of the hydraulic cylinder 6.

[0052] The pressure sensor 11 outputs the real-time pressure value inside the hydraulic cylinder 6 to the simulator electronic control unit 10, and compares it with the required target pressure value, forming a closed-loop PID control system with feedback to perform real-time control on the pressure value inside the hydraulic cylinder 6.

[0053] Specifically, according to the mathematical model of the elastic element, the characteristic equation of the acting force F1 of the damping elastic element 8 and the stroke S of the brake pedal is obtained:

[0054] ;

[0055] Wherein, F1 is the acting force of the damping elastic element 8, S0 is the displacement of the piston push rod 7, K1 is the stiffness of the elastic element, i is the lever ratio of the brake pedal, and S is the stroke of the brake pedal.

[0056] Therefore, the relationship between the elastic stiffness of the damping elastic element 8 and the pedal stroke shows a linear change.

[0057] The relational expression obtained from the mathematical model of the pressure P of the hydraulic cylinder 6 and the volume V of the brake fluid:

[0058] ;

[0059] Wherein, a and b are fitting coefficients, and V is the volume of the brake fluid.

[0060] Calculate the thrust F2 of the piston push rod of the hydraulic cylinder 6, and obtain the mathematical model of the hydraulic pressure and the pedal stroke:

[0061] ;

[0062] Wherein, F2 is the thrust of the piston push rod of the hydraulic cylinder 6, A is the piston area of the hydraulic cylinder 6, and K2 is the elastic modulus of the brake fluid.

[0063] Therefore, the mathematical model of the pedal force F and the pedal travel S of the brake pedal can be obtained:

[0064] .

[0065] In the simulator electronic control unit 10 provided in this embodiment, a PID control algorithm and a fuzzy control algorithm for simulating the braking intention of the driver are built in. Through the combined control of the PID control algorithm and the fuzzy control algorithm, the demand of the driver for the feedback force of the brake pedal can be better simulated.

[0066] Among them, the input parameters of the simulator electronic control unit 10 are the brake pedal displacement and the change rate of the brake pedal displacement, and the control parameter of the simulator electronic control unit 10 is the thrust of the piston push rod output by the hydraulic cylinder 6.

[0067] The simulator electronic control unit 10 calculates the demand coefficient f of the feedback force of the brake pedal required by the driver through the fuzzy control algorithm, and obtains the mathematical model of the target brake pedal force Fm:

[0068] F m = F max * f;

[0069] Among them, F max is the maximum pedal force of the brake pedal, and f is the demand coefficient of the feedback force of the brake pedal.

[0070] The simulator electronic control unit 10 provided in the embodiment of the present invention calculates the feedback force value of the pedal jointly according to the displacement amount of the pedal of the brake pedal operating mechanism 1 and the in-cylinder pressure value of the hydraulic cylinder 6, and controls the pressure in the hydraulic cylinder 6 by quickly adjusting the first high-speed switching valve 13 and the second high-speed switching valve 14, and adjusts the output force of the piston of the hydraulic cylinder 6. The pressure sensor 11 located in the hydraulic cylinder 6 inputs the real-time pressure in the hydraulic cylinder to the simulator electronic control unit 10, and the simulator electronic control unit 10 compares it with the required target pressure value, thereby forming a PID control system with a feedback closed loop, so as to accurately and real-time control the pressure value of the hydraulic cylinder 6.

[0071] The decoupled brake pedal simulation device provided by the embodiments of the present invention simulates the brake pedal feedback force through the hydraulic components in the hydraulic cylinder 6 and the damping elastic element 8 arranged inside the hydraulic cylinder 6. The hydraulic components and the elastic element have good linear feedback force, and can well simulate the pedal feedback force of the brake pedal of a traditional internal combustion engine, conforming to the braking characteristics of the original internal combustion engine pedal. The simulator electronic control unit 10 provided by the embodiments of the present invention presets a PID control algorithm and a fuzzy control algorithm for simulating the braking intention of the driver. The controller based on the fuzzy control algorithm can well simulate the driver's demand for braking force and better simulate the driver's braking intention. The PID control algorithm can accurately and real-time follow the pedal force preset by the target. In the actual use process of the decoupled brake pedal simulation device provided by the embodiments of the present invention, the brake pedal feedback force is appropriate and has good linearity. This device is simple to assemble and convenient to maintain.

[0072] Although the preferred embodiments of the embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention. Finally, it should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or terminal device including the element.

[0073] The decoupled brake pedal simulation device provided by the embodiments of the present application has been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or equivalently replace some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A decoupled brake pedal simulation device, characterized in that, The decoupled brake pedal simulation device includes: A brake pedal operating mechanism, and a hydraulic cylinder connected to the brake pedal operating mechanism; the hydraulic cylinder is connected to a first high-speed switching valve and a second high-speed switching valve through an oil pipe, and the other end of the first high-speed switching valve is connected to a hydraulic pump; the hydraulic pump is connected to a motor, and the motor drives the hydraulic pump; the other end of the first high-speed switching valve is also connected to a relief valve through an oil pipe, and the other end of the relief valve is connected to an accumulator; A simulator electronic control unit, a displacement sensor connected to the simulator electronic control unit, and the displacement sensor is connected to the brake pedal operating mechanism; a pressure sensor located inside the hydraulic cylinder is connected to the simulator electronic control unit; the first high-speed switching valve and the second high-speed switching valve are connected to the simulator electronic control unit; Stepping on the brake pedal operating mechanism pushes the piston of the hydraulic cylinder to displace, the displacement sensor outputs the measured displacement signal of the brake pedal to the simulator electronic control unit, and the pressure sensor outputs the measured pressure signal inside the hydraulic cylinder to the simulator electronic control unit; The brake pedal operating mechanism is a hanging stepping mechanism, the upper bracket of the brake pedal operating mechanism is installed on the front body panel, and the lower bracket of the brake pedal operating mechanism is installed on the vehicle body floor; the brake pedal arm of the brake pedal operating mechanism is connected to the piston push rod of the hydraulic cylinder through a connecting fork; The hydraulic cylinder includes a cylinder block, a damping elastic element arranged inside the cylinder block, and a hydraulic cylinder piston arranged inside the cylinder block, and a sealing element is arranged on the outer circumferential surface of the hydraulic cylinder piston to seal the cylinder block; One end of the hydraulic cylinder piston is connected to the brake pedal arm through the piston push rod, and the other end of the hydraulic cylinder piston is connected to the damping elastic element; The first high-speed switching valve and the second high-speed switching valve control the oil pressure output through PWM pulse width modulation technology; when the pulse is at a high level, the electromagnets in the first high-speed switching valve and the second high-speed switching valve are energized to generate suction; when the pulse is at a low level, the electromagnets in the first high-speed switching valve and the second high-speed switching valve are de-energized, and the suction generated by the electromagnets is zero; By changing the duty cycle of the pulse width, the on-off time of the electromagnets inside the first high-speed switching valve and the second high-speed switching valve is changed, and the valve port sizes of the first high-speed switching valve and the second high-speed switching valve are changed to achieve the control of the pressure of the brake cylinder; Calculating the thrust F2 of the piston push rod of the hydraulic cylinder includes: Calculating the pressure P of the hydraulic cylinder; ； where a and b are fitting coefficients, and V is the volume of the brake fluid; Calculating the thrust F2 of the piston push rod of the hydraulic cylinder; ； where A is the piston area of the hydraulic cylinder, K2 is the elastic modulus of the brake fluid, i is the lever ratio of the brake pedal, and S is the stroke of the brake pedal.

2. The decoupled brake pedal simulation device according to claim 1, wherein The damping elastic element includes but is not limited to multi-stage springs, and the stiffness of the multi-stage springs is determined according to the maximum value of the brake pedal force.

3. The decoupled brake pedal simulation device according to claim 1, characterized in that The displacement sensor is installed on the side of the piston push rod, and the displacement sensor converts the measured analog signal of the piston push rod displacement into a digital signal through an A / D converter and transmits it to the electronic control unit of the simulator.

4. The decoupled brake pedal simulation device according to claim 1, characterized in that The electronic control unit of the simulator calculates the reaction force value of the pedal based on the displacement of the brake pedal operating mechanism and the pressure of the hydraulic cylinder, and controls the pressure in the hydraulic cylinder by adjusting the first high-speed switching valve and the second high-speed switching valve to adjust the output force of the piston of the hydraulic cylinder. The pressure sensor outputs the real-time pressure value in the hydraulic cylinder to the electronic control unit of the simulator, and compares it with the required target pressure value to form a closed-loop PID control system with feedback to control the pressure value in the hydraulic cylinder in real time.

5. The decoupled brake pedal simulation device according to claim 4, characterized in that, Calculating the reaction force value of the pedal includes: calculating the acting force F1 of the elastic element. ； Among them, S0 is the displacement of the piston push rod, K1 is the stiffness of the elastic element, i is the lever ratio of the brake pedal, and S is the stroke of the brake pedal.

6. The decoupled brake pedal simulation device according to claim 5, wherein Calculating the pedal force F and the pedal stroke S of the brake pedal includes: ； The electronic control unit of the simulator is built-in with a PID control algorithm and a fuzzy control algorithm for simulating the braking intention of the driver. The input parameters of the electronic control unit of the simulator are the brake pedal displacement and the brake pedal displacement change rate, and the control parameter of the electronic control unit of the simulator is the thrust of the piston push rod output by the hydraulic cylinder.

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