Pedal feel emulation device and method with active redundancy and variable feel functionality

Abstract

The application discloses a pedal feeling simulation device and method with active redundancy and variable pedal feeling, and the pedal push rod provided with front and rear shaft shoulders penetrates the rear cavity, left cavity and right cavity in sequence; the air pressure sensor, displacement sensor and air compressor are connected with the ECU signal, the right cavity is in cut-off communication with the air compressor and / or air cylinder through valve control, and the air compressor is in communication with the high-pressure air cylinder through valve control; the air pressure sensor is arranged to collect the pressure of the right cavity and air spring, and the displacement sensor is arranged to collect the displacement of the front end of the pedal push rod; the electric power booster and brake master cylinder are connected with the force feedback disc; and the force feedback disc and the front end of the pedal push rod are provided with a set gap. The double-energy guarantee system is safe in failure. The differential pressure control of the right cavity and air spring is used to realize the free conversion function of variable pedal feeling. Meanwhile, the brake response speed in the failure working mode can be improved.

Description

Technical Field

[0001] This invention relates to the field of motor vehicle pedal feel simulator technology, and in particular to a feel simulator and simulation control method that uses air springs for force feedback and has two failure modes. Background Technology

[0002] A primary function of pedal feel simulators is to provide force feedback to the driver. Pedal feel simulators can be categorized into active and passive types based on their ability to simulate different pedal sensations. However, many current active simulators can only provide pedal sensation simulations in fixed settings such as comfort, standard, and sport modes. The simulated sensations cannot change according to actual conditions, resulting in a low degree of simulation of the process of movement.

[0003] Secondly, the pedal feel simulation device is part of the braking system. The most serious failure of the braking system is the loss of the active power source. The safety of the single power source in the failure state also becomes a major threat to the pedal feel simulation device.

[0004] Therefore, safety redundancy designs can also be considered. The most serious failure scenario for a braking system is the loss of the active power source. The power source of the active pedal feel simulation device can serve as a second power source to provide braking assistance, thereby improving safety. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to design a pedal feel simulation device and method with active redundancy and variable feel function through structural improvement, which can realize the simulation of countless pedal feel in multiple pedal modes; at the same time, it has dual safety redundancy function and can improve the braking response speed when working in the disabled working mode.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A pedal feel simulation device with active redundancy and variable sensitivity, characterized in that it comprises:

[0008] The pedal feel simulator body, air control system and brake master cylinder assembly;

[0009] The pedal feel simulator is divided into a rear cavity, a left cavity, and a right cavity, all coaxially arranged. A pedal push rod with a front and rear axle shoulder passes through the rear, left, and right cavities sequentially. The rear end of the pedal push rod connects to the pedal. A pressure ring spring is installed between the rear axle shoulder of the pedal push rod and the air filter device that seals the rear cavity. A rubber force feedback disc is installed adjacent to the front axle shoulder between the front axle shoulder of the pedal push rod and the closed end of the right cavity. An air spring is installed between the rubber force feedback disc and the closed end of the right cavity. The rubber force feedback disc separates the left and right cavities. A rebound spring is installed on the end face of the rubber force feedback disc facing the rear axle shoulder. This rebound spring is located between the end wall of the left cavity and the rubber force feedback disc and is compressed or released along the pedal push rod. An air valve is installed at the junction of the rear and left cavities. The pedal push rod is designed to move under the action of pedal force and pressure differential force.

[0010] The air control system includes an air compressor, a gas cylinder, a pressure sensor, a displacement sensor, and several pneumatic solenoid valves. The pressure sensor, displacement sensor, and air compressor are all connected to the ECU signal. The right chamber is connected to the air compressor in a valve-controlled manner, and the air compressor is connected to the high-pressure gas cylinder in a valve-controlled manner. A pressure sensor is installed at the closed end of the right chamber facing the first interface to collect the pressure of the right chamber and the air spring. The displacement sensor is set to collect the displacement of the front end of the pedal push rod.

[0011] The brake master cylinder assembly includes an electric booster, a force feedback disc, and a brake master cylinder. Both the electric booster and the brake master cylinder are connected to the force feedback disc. There is a set gap between the force feedback disc and the front end of the pedal push rod.

[0012] In the above technical solution, the end face wall of the left cavity is parallel and of equal length to the closed end of the right cavity, so that the diameters of both the left and right cavities are larger than the rear cavity.

[0013] In the above technical solution, the pressure ring spring is placed between the fixed pressure ring and the sliding pressure ring, and both the fixed pressure ring and the sliding pressure ring are sleeved on the pedal push rod.

[0014] In the above technical solution, the air valve is located between the sliding pressure ring and the rear axle shoulder and circumferentially seals the shoulder space between the rear axle shoulder and the rear cavity in the closed state. The sliding pressure ring has a hole that communicates with the air valve through hole, so that when the air valve is open, the rear cavity communicates with the shoulder space at the other end of the rear axle shoulder through the hole and the air valve through hole; the shoulder space and the left cavity are connected through a circumferential through hole; the shoulder space is connected to the right cavity through a front-back channel, which is composed of a partition fixed on the rubber force feedback disc and the circumferential outer wall of the shoulder space, and can be blocked by the displacement action of the air valve.

[0015] In the above technical solution, the force-bearing point at the rear end of the pedal push rod is located at the hinge axis of the pedal.

[0016] In the above technical solution, the axial center of the air spring installed in the right cavity is hollowed out and does not interfere with the pedal push rod.

[0017] In the above technical solution, the rubber force feedback disc is made of elastic rubber and is fixedly connected to the pedal push rod.

[0018] In the above technical solution, the high-pressure gas cylinder is connected to the air spring and the right chamber respectively through a four-position four-way solenoid valve, and the high-pressure gas cylinder is connected to the air compressor through the first two-position three-way solenoid valve; the air compressor is connected to the air spring and the right chamber respectively through the second two-position three-way solenoid valve; the interface connection status of the four-position four-way solenoid valve and the two-position three-way solenoid valve in the power-off state are AB, BC and BC respectively.

[0019] The working principle of this invention is as follows:

[0020] The movement of the air valve in the rear chamber is constrained by the sliding pressure ring and the shoulder of the pedal push rod, thus cutting off or connecting the airflow between the rear and left chambers. The rubber force feedback disc between the left and right chambers has good elasticity and is fixedly connected to the pedal push rod. The air spring in the right chamber is mainly used to simulate the pedal feel.

[0021] The feedback disc of the brake master cylinder assembly and the pedal push rod in the simulator body have a certain set gap △h to achieve partial decoupling.

[0022] In normal operating mode, the air compressor continuously supplies air to the air spring, and the second 2-position 3-way solenoid valve is in the B and C position. The driver can select a custom mode, in which they need to provide the percentage of each of the two system's fixed modes. The system's fixed modes can be understood as pre-set pedal feel simulation modes at the factory, such as Sport mode and Comfort mode. In different fixed modes, the feedback force applied by the pedal feel simulation device per unit pedal travel cannot be changed by the user. However, in custom mode, the user can manually change the feedback force applied by the pedal feel simulation device per unit pedal travel. The ECU updates a new curve based on the "pedal travel-feedback force curve" of the two system fixed modes and the percentage provided by the driver, and controls the force feedback accordingly. The "pedal travel-feedback force curve" update process is as follows: Figure 3 As shown. By controlling the air pressure in the air spring, a continuous change in pedal feel can be achieved. The specific control method is as follows: Figure 4 As shown.

[0023] In this article, the active power is provided by an electric booster, and the backup power is provided by an air compressor.

[0024] In the first failure mode, both the electric booster and the air compressor fail simultaneously.

[0025] In the first disabled operating mode, both the active power and backup power fail simultaneously. That is, the electric booster and air compressor fail at the same time. At this time, the AB interface of the four-position four-way solenoid valve is connected. The rubber force feedback disc, under the action of its own elasticity and the rebound spring, drives the pedal push rod to the right until it contacts the force feedback disc, eliminating the set gap Δh. When the rubber force feedback disc and the rebound spring are in a free position, Δh is zero or close to zero, ensuring that the gap Δh can be automatically eliminated. The gap Δh does not need to be overcome before establishing brake pressure, improving the braking response speed in the disabled operating mode.

[0026] In the second disabled operating mode, the electric booster cannot function properly, but the air compressor still operates normally. In this mode, the air compressor remains continuously on, creating a certain vacuum at its air input. By controlling the opening and closing of specific valves, the air input of the air compressor can be connected to the air spring and the right chamber, reducing the pressure in the air spring and the right chamber. When the driver does not apply the brakes, the air valve isolates the rear chamber from the left chamber. The four-position four-way solenoid valve is in the AD position, the first two-position three-way solenoid valve is in the B and C position, and the second two-position three-way solenoid valve is in the AC position, causing a decrease in air pressure in the air spring and the left and right chambers. When the driver applies the brakes, the air valve moves to the right until it completely covers the front-rear passage a port, cutting off the connection between the left and right chambers. At this time, outside air enters the rear chamber through the air filter and then enters the left chamber through the sliding pressure ring orifice f. At this time, there is a pressure difference between the left and right sides of the rubber force feedback disc. This pressure difference is in the same direction as the pedal force applied by the driver, and together they act on the force feedback disc to establish brake fluid pressure. When the driver releases the brake pedal, under the action of the rubber force feedback disc's own elasticity and the hydraulic reaction force of the brake master cylinder, the pedal push rod moves to the left, opening the front-rear channel a while cutting off the connection between the rear chamber and the left chamber, so that there is no pressure difference between the left and right sides of the rubber force feedback disc, thus disengaging the brake assist. It is particularly worth noting that the principle by which Δh can be automatically eliminated is the same in both the second and first failure modes.

[0027] Furthermore, based on the above-mentioned device, the present invention also provides a pedal feel simulation method with active redundancy and variable sensitivity, characterized by including at least the following steps:

[0028] S1: Steps for measuring pedal push rod displacement:

[0029] S11) Starting with vehicle startup and power-on, read the current pedal push rod displacement. ;

[0030] S12) Judgment If so, the output board push rod displacement If not, output ; The brake pedal is set to be in a doubly engaged position;

[0031] S13) Determine if the vehicle is turned off or powered off. If yes, end; if no, return to step S11).

[0032] S2: Control steps for the air spring in normal operating mode:

[0033] S21) Displacement of the output plate push rod To begin, the pedal mode is first read to determine the "pedal displacement-feedback force curve";

[0034] S22) Read ;

[0035] S23) Based on the "pedal displacement-feedback force curve" and Determine the target air pressure ;

[0036] S24) Read the air pressure of the air spring. ;

[0037] S25) Judgment If yes, proceed to the next step sequentially; if no, the valve port AB of the four-position four-way solenoid valve is connected, the air spring is depressurized, and then the process jumps to step S28).

[0038] S26) Judgment If yes, proceed to the next step; if no, the valve port A-none of the four-position four-way solenoid valve is connected, the air spring maintains pressure, and then proceed to step S28).

[0039] S27) When the AC port of the four-position four-way solenoid valve is connected, the air spring pressurizes the valve.

[0040] S28) Read ;

[0041] S29) Judgment If yes, then end; if no, then return to S23).

[0042] S3: Control steps for filling and discharging high-pressure gas cylinders under normal operating mode:

[0043] S31) Read the target gas pressure of the gas cylinder ;

[0044] S32) Read the gas cylinder pressure ;

[0045] S33) ;

[0046] S34) Judgment If yes, proceed to the next step; if no, proceed to S341).

[0047] S341) Judgment If yes, proceed to S342); if no, end.

[0048] S342) Start the air compressor;

[0049] S343) Solenoid valve 10 AC is turned on for a period of time t, and then returns to S32).

[0050] S35) Judgment If yes, then end; if no, return to S343).

[0051] Where △p is the margin when filling the high-pressure gas cylinder.

[0052] Furthermore, the present invention also includes the step of fitting a new "pedal travel-feedback force curve" in a custom mode based on the driver's selection:

[0053] S41) Select two existing fixed pedal modes, M and N;

[0054] S42) provides two percentages m and n for pedal modes M and N, where m and n must satisfy... Relationship;

[0055] S43) Take the pedal displacement ;

[0056] S44) Based on the "pedal travel-feedback force curve" stored in the ECU controller, take the... The pedal feedback force corresponding to M mode and N mode is as follows: and ;

[0057] S45) Obtain the custom mode. Corresponding pedal feedback force :

[0058] ;

[0059] S46) ;

[0060] S47) Judgment =max If yes, then end; if no, return to S43).

[0061] in, The unit pedal displacement is manually set according to the actual situation. The percentages m and n can be input via the knob.

[0062] Furthermore, the pedal displacement-feedback force curve is a graph stored in the controller based on the relationship between pedal displacement and pedal feedback force, including at least two or more fixed modes, and a custom mode where the pedal feedback force is between the feedback forces of the two fixed modes.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] (1) It has dual safety redundancy function. The present invention senses that the simulator is set with dual power sources, including a second energy source that can be used as the active power source of the braking system. That is, the whole system has two power sources that can be used for braking, which makes it safer.

[0065] (2) When the control system detects that the electric booster has failed, it can automatically eliminate the set gap △h between the set pedal push rod and the air spring, thereby improving the braking response speed when working in the disabled working mode.

[0066] (3) By selecting the pedal displacement according to the set curve, the simulation of countless pedal sensations in various pedal modes can be realized, thus realizing the variable pedal sensation function.

[0067] (4) If the present invention is installed on a car with air suspension, it can share a set of air charging and storage device, making the whole structure more compact. Attached Figure Description

[0068] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0069] Figure 1 This is a structural diagram of the pedal feel simulation device module with active redundancy and variable sensing function according to the present invention.

[0070] Figure 2 This is a schematic diagram of the overall structure of the pedal feel simulation device with active redundancy and variable sensing function according to the present invention. The reference numerals in the figure are as follows:

[0071] 1. Brake pedal; 2. Air filter; 3. Fixed pressure ring; 4. Pressure ring spring; 5. Sliding pressure ring; 6. Air valve; 7. Rebound spring; 8. Left cover; 9. Four-position four-way solenoid valve; 10. Two-position three-way solenoid valve; 11. Two-position three-way solenoid valve; 12. Right cover; 13. Air spring; 14. Rubber force feedback disc; 15. Pedal push rod; 16. High-pressure gas cylinder; 17. Air compressor; 18. Displacement sensor; 19. Brake master cylinder; 20. Force feedback disc; 21. Electric booster; 22. Air pressure sensor.

[0072] Figure 3This is a flowchart illustrating the method for updating the "pedal travel-feedback force curve" in normal operation mode using the pedal feel simulation device with active redundancy and variable sensing function of the present invention.

[0073] Figure 4 This is a flowchart of the air spring control method of the present invention in normal working mode.

[0074] Figure 5 This is a flowchart of the control method for measuring the displacement of the pedal push rod according to the present invention.

[0075] Figure 6 This is a flowchart of the control method for filling and discharging high-pressure gas cylinders under normal operating conditions according to the present invention.

[0076] Figure 7 This is a graph showing the pedal travel-feedback force of the present invention. Detailed Implementation

[0077] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0078] This invention provides an air-type pedal feel simulator with active redundancy and variable pedal feel, which can be divided into three parts: the pedal feel simulator body, the air control system, and the brake master cylinder assembly. Its modular structure diagram is shown below. Figure 1 As shown, the specific structure is as follows: Figure 2 As shown. The mode in which the pedal feel simulation equipment operates when both the active and backup power sources of the braking system fail is referred to as the first disabled operating mode, and the mode in which the active power source fails but the backup power source is effective is referred to as the second disabled operating mode.

[0079] The pedal feel simulator is divided into three parts: a rear chamber, a left chamber, and a right chamber. In the rear chamber, the movement of the air valve 6 is constrained by the sliding pressure ring and the shoulder of 15, effectively cutting off or connecting the airflow between the rear and left chambers. The rubber force feedback disc 14 between the left and right chambers has good elasticity and is fixedly connected to the pedal push rod 15. The air spring 13 in the right chamber is mainly used to simulate the pedal feel; its central part is hollow to prevent interference with the pedal push rod 15.

[0080] The pedal feel simulator is divided into a rear cavity, a left cavity, and a right cavity arranged coaxially. A pedal push rod 15 with a front axle shoulder and a rear axle shoulder passes through the rear cavity, the left cavity, and the right cavity in sequence. The rear end of the pedal push rod 15 is connected to the brake pedal 1. A pressure ring spring 4 is set between the rear axle shoulder of the pedal push rod 15 and the air filter device 2 that seals the rear cavity. A rubber force feedback disc 14 is set close to the front axle shoulder between the front axle shoulder of the pedal push rod 15 and the closed end of the right cavity. An air spring 13 is set between the rubber force feedback disc 14 and the closed end of the right cavity. The rubber force feedback disc 14 separates the left cavity and the right cavity. A rebound spring 7 is set on the end face of the rubber force feedback disc 14 facing the rear axle shoulder. The rebound spring 7 is set between the end face cavity wall of the left cavity and the rubber force feedback disc 14 and is compressed or released along the pedal push rod. An air valve 6 is set at the junction of the rear cavity and the left cavity. The pedal push rod 15 is designed to move under the action of pedal force and pressure difference force.

[0081] The pressure ring spring 4 is positioned between the fixed pressure ring 3 and the sliding pressure ring 5, and both the fixed pressure ring and the sliding pressure ring are sleeved on the pedal push rod 15.

[0082] Air valve 6 is located between sliding pressure ring 5 and rear axle shoulder, and in the closed state, it circumferentially seals the shoulder space between the rear axle shoulder and the rear cavity. The sliding pressure ring is provided with a hole f that communicates with the air valve through hole, so that when the air valve is open, the rear cavity communicates with the shoulder space at the other end of the rear axle shoulder through the hole f and the air valve through hole; the shoulder space and the left cavity are connected through the circumferential through hole b; the shoulder space is connected to the right cavity through the front-back channel a. The front-back channel a is composed of a partition fixed on the rubber force feedback disc and the circumferential outer wall of the shoulder space, and can be blocked by the displacement action of the air valve.

[0083] The brake master cylinder assembly includes an electric booster 21, a force feedback disc 20, and a master cylinder 19. The force feedback disc 20 has a certain gap Δh with the pedal push rod 15 in the simulator body, thereby achieving partial decoupling.

[0084] The air control system includes an air compressor 17, a gas cylinder 16, a sensor 22 for measuring gas pressure, a sensor 18 for measuring the displacement of the pedal push rod 15, an ECU, and several pneumatic solenoid valves.

[0085] Among several pneumatic solenoid valves, the valve port connection states of the four-position four-way solenoid valve 9, the first two-position three-way solenoid valve 10, and the second two-position three-way solenoid valve 11 in the de-energized state are AB, BC, and BC, respectively.

[0086] In normal operating mode, air compressor 17 continuously supplies air to air spring 13, and the second two-position three-way solenoid valve 11 is in the BC-on state. The driver can select a custom mode, in which the driver needs to provide the percentage of each of the two system fixed modes. The ECU updates a new curve based on the weighted average of the "pedal travel-feedback force curves" from the two system fixed modes and the percentages provided by the driver, and controls the force feedback according to this curve. The "pedal travel-feedback force curve" update process is as follows: Figure 3 As shown. By controlling the air pressure in the air spring 13, a continuous change in pedal feel can be achieved. The specific control method is as follows: Figure 4 As shown.

[0087] In the first disabled operating mode, both the active power and the backup power fail simultaneously. At this time, the valve ports AB of the four-position four-way valve 9 are closed. The rubber force feedback disc 14, under its own elasticity and the action of the rebound spring 7, drives the pedal push rod 15 to move to the right until it contacts the force feedback disc C, eliminating Δh. When the rubber force feedback disc 14 and the rebound spring 7 are in their free positions, Δh is zero or close to zero, ensuring that the gap Δh can be automatically eliminated. The gap Δh does not need to be overcome before establishing brake oil pressure, improving the braking response speed in the disabled operating mode.

[0088] In the second disabled operation mode, the electric brake assist device cannot function properly, but the air compressor still functions properly. At this time, the air compressor remains continuously on, and its air input end generates a certain degree of vacuum. By controlling the opening and closing of specific valves, the air input end of the air compressor 17 can be connected to the air spring 13 and the right chamber, reducing the pressure in the air spring 13 and the right chamber. When the driver does not apply the brakes, the air valve 6 isolates the rear chamber from the left chamber. Valve 9 is in the AD closed state, valve 10 is in the BC closed state, and valve 11 is in the AC closed state, causing the air pressure in the air spring 13 and the left and right chambers to decrease. When the driver applies the brakes, the air valve 6 moves to the right until it completely covers the port of channel a, cutting off the connection between the left and right chambers. At this time, outside air enters the rear chamber through the air filter 2, and then enters the left chamber through the groove f. At this time, there is a pressure difference between the left and right sides of the rubber force feedback disc 14. This pressure difference is in the same direction as the pedal force applied by the driver, and together they act on the force feedback disc to establish brake fluid pressure. When the driver releases the brake pedal, under the action of the elasticity of the rubber force feedback disc 14 and the hydraulic reaction force of the brake master cylinder, the pedal push rod 15 moves to the left, opening channel a and simultaneously cutting off the connection between the rear chamber and the left chamber, so that there is no pressure difference between the left and right sides of the rubber force feedback disc 14, thus releasing the brake assist. It is particularly worth noting that the principle by which Δh can be automatically eliminated is consistent in both the second and first disability operating modes.

[0089] like Figure 5 As shown, the control method for measuring the displacement of the pedal push rod used in this invention includes the following processes:

[0090] 1) Starting with vehicle startup and power-on, read the push rod displacement. ;

[0091] 2) Judgment If yes, then output If not, output ;

[0092] 3) Determine if the vehicle is off or powered down. If yes, end the process; otherwise, return to step 1).

[0093] The control method for measuring the displacement of the pedal push rod used in this invention also takes into account the actual situation that the brake pedal has a play. The brake pedal play setting is designed to reduce erroneous braking behavior caused by measurement errors of sensor F or driver misoperation.

[0094] like Figure 6 As shown, the air spring control method of the present invention in normal operating mode includes the following processes:

[0095] 1) Displacement of pedal push rod 15 To begin, the pedal mode is first read to determine the "pedal displacement-feedback force curve";

[0096] 2) Read ;

[0097] 3) Based on the "pedal displacement-feedback force curve" and Determine the target air pressure ;

[0098] 4) Read the air pressure of the air spring 13 ;

[0099] 5) Judgment If yes, proceed to the next step; if no, valve 9AB is activated, air spring 13 is depressurized, and then proceed to step 8).

[0100] 6) Judgment If yes, proceed to the next step; if no, valve 9 A-none is turned on, air spring 13 maintains pressure, and then proceed to step 8).

[0101] 7) Valve 9 AC is turned on, and air spring 13 pressurizes;

[0102] 8) Read ;

[0103] 9) Judgment If yes, then end; if no, then return to step 3).

[0104] like Figure 4 As shown, the present invention employs a control method for filling and discharging high-pressure gas cylinders under normal operating conditions, comprising the following processes:

[0105] 1) Read the target gas pressure of the gas cylinder ;

[0106] 2) Read the gas cylinder pressure ;

[0107] 3) ;

[0108] 4) Judgment If yes, proceed to the next step; if no, proceed to 4.1).

[0109] 4.1) Judgment If yes, proceed to 4.2); if no, end.

[0110] 4.2) Start the air compressor 17;

[0111] 4.3) Solenoid valve 10 AC is turned on for a period of time t, and then returns to 2).

[0112] 5) Judgment If yes, then end; if no, return to 4.3).

[0113] Where △p is the allowance for filling the high-pressure gas cylinder, to prevent pressure buildup due to cylinder pressure issues. Slightly lower than the target pressure of the gas cylinder The frequent start-stop cycles of the solenoid valve 10 and the air compressor 17 will reduce its service life. After the air compressor 17 starts, if it does not receive a start request from the ECU within a certain period of time T, it will stop. If it receives a start request from the ECU within a certain period of time T after starting, the timer will restart from the moment the start request is received.

[0114] like Figure 3 As shown, fitting a new "pedal travel-feedback force curve" based on the driver's selection in custom mode involves the following process:

[0115] 1) Select two system-fixed pedal modes, M and N;

[0116] 2) Provide two percentages m and n about M and N, where m and n must satisfy... Relationship;

[0117] 3) Take the pedal displacement ;

[0118] 4) Based on a fixed "pedal travel-feedback force curve" such as Figure 7 As shown, take this The pedal feedback force corresponding to M mode and N mode is as follows: and ;

[0119] 5) Obtain the value in custom mode Corresponding pedal feedback force ,

[0120] ;

[0121] 6) ;

[0122] 7) Judgment =max If yes, then end; if no, then return to step 3).

[0123] in, The unit pedal displacement can be manually set according to actual conditions. The percentages m and n can be input via the knob.

[0124] Figure 7 In the "Pedal Travel-Feedback Force Curve" shown, the pedal feedback force is smaller in M ​​mode, larger in N mode, and intermediate in custom mode. Figure 7 The horizontal axis represents the pedal travel in mm. The vertical axis represents the feedback force of the pedal feel simulation device in N. M and N are the fixed modes already present in the system, defined as the pedal feel simulation modes preset at the factory, such as sport and comfort modes. In different fixed modes, the feedback force applied by the pedal feel simulation device per unit pedal travel cannot be changed by the user. The custom mode allows the user to change the feedback force applied by the pedal feel simulation device per unit pedal travel. Figure 7 The inflection points of each curve indicate that the electric power booster is about to reach its assist limit and will be unable to apply more force to the force feedback disc. The driver is informed of this situation by increasing the feedback force applied by the simulation device per unit pedal travel.

[0125] Both M and N modes operate in the normal working mode of the pedal feel simulation device, which is a fixed pedal feel simulation mode in the system. The custom mode also operates in the normal working mode of the simulation device. In this mode, the active power source applies force to the force feedback disc, while the backup power source provides energy to the pedal feel simulation device. In custom mode, the driver needs to provide the percentage of each of the two fixed system modes. The ECU updates a new curve based on the weighted average of the "pedal travel-feedback force curve" from the two fixed system modes and the percentage provided by the driver, and then controls the force feedback according to this curve. The "pedal travel-feedback force curve" update process is as follows: Figure 3 As shown. The specific calculation process for weighting is as follows: the feedback force applied per unit pedal travel in M ​​mode is multiplied by the percentage corresponding to M mode, and the feedback force applied per unit pedal travel in N mode is multiplied by the percentage corresponding to N mode. The sum of the two results gives the feedback force applied per unit pedal travel in custom mode.

[0126] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A pedal feel simulation device with active redundancy and variable sensing function, characterized in that... include: The pedal feel simulator body, air control system and brake master cylinder assembly; The pedal feel simulator is divided into a rear cavity, a left cavity, and a right cavity set on the same axis. The pedal push rod with a front axle shoulder and a rear axle shoulder passes through the rear cavity, the left cavity, and the right cavity in sequence. The rear end of the pedal push rod is connected to the pedal. A pressure ring spring is installed between the rear axle shoulder of the pedal push rod and the air filter device that seals the rear cavity. A rubber force feedback disc is installed close to the front axle shoulder between the front axle shoulder of the pedal push rod and the closed end of the right cavity. An air spring is installed between the rubber force feedback disc and the closed end of the right cavity. The rubber force feedback disc separates the left and right cavities. A rebound spring is installed on the end face of the rubber force feedback disc facing the rear axle shoulder. The rebound spring is located between the end face cavity wall of the left cavity and the rubber force feedback disc and is compressed or released along the pedal push rod. An air valve is installed at the junction of the rear and left cavities. The pedal push rod is designed to move under the action of pedal force and pressure differential force. The pressure ring spring is positioned between the fixed pressure ring and the sliding pressure ring, and both the fixed pressure ring and the sliding pressure ring are sleeved on the pedal push rod; An air valve is located between the sliding pressure ring and the rear axle shoulder, and in the closed state, it circumferentially seals the shoulder space between the rear axle shoulder and the rear cavity. The sliding pressure ring has a hole that communicates with the air valve through hole, so that when the air valve is open, the rear cavity communicates with the shoulder space at the other end of the rear axle shoulder through the hole and the air valve through hole. The shoulder space and the left cavity are connected through a circumferential through hole. The shoulder space is connected to the right cavity through a front-to-back channel, which is composed of a partition fixed on a rubber force feedback disc and the circumferential outer wall of the shoulder space, and can be blocked by the displacement action of the air valve. The air control system includes an air compressor, a gas cylinder, a pressure sensor, a displacement sensor, and several pneumatic solenoid valves. The pressure sensor, displacement sensor, and air compressor are all connected to the ECU signal. The right chamber is connected to the air compressor in a valve-controlled manner, and the air compressor is connected to the high-pressure gas cylinder in a valve-controlled manner. A pressure sensor is set to collect the pressure of the right chamber and the air spring, and a displacement sensor is set to collect the movement displacement of the front end of the pedal push rod. The brake master cylinder assembly includes an electric booster, a force feedback disc, and a brake master cylinder. Both the electric booster and the brake master cylinder are connected to the force feedback disc. There is a set gap between the force feedback disc and the front end of the pedal push rod.

2. The pedal feel simulation device with active redundancy and variable sensing function according to claim 1, characterized in that... The force point at the rear end of the pedal push rod is located at the hinge axis of the pedal.

3. The pedal feel simulation device with active redundancy and variable sensing function according to claim 1, characterized in that... The air spring in the right cavity has an axial center cutout and does not interfere with the pedal push rod.

4. The pedal feel simulation device with active redundancy and variable sensing function according to claim 1, characterized in that... The rubber force feedback disc is made of elastic rubber and is fixedly connected to the pedal push rod.

5. The pedal feel simulation device with active redundancy and variable sensing function according to claim 1, characterized in that... The high-pressure gas cylinder is connected to the air spring and the right chamber through a four-position four-way solenoid valve. The high-pressure gas cylinder is connected to the electric booster and the air compressor through the first two-position three-way solenoid valve. The air compressor is connected to the air spring and the right chamber through the second two-position three-way solenoid valve. The valve ports of the four-position four-way solenoid valve and the two-position three-way solenoid valve are AB, BC, and BC respectively when the power is off.

6. A pedal feel simulation method with active redundancy and variable sensing function, characterized in that... The implementation of the pedal feel simulation device with active redundancy and variable sensing function according to any one of claims 1-5 includes at least the following steps: S1: Steps for measuring pedal push rod displacement: S11) Starting with vehicle startup and power-on, read the current pedal push rod displacement. ; S12) Judgment If so, the output board push rod displacement If not, output ; The brake pedal is set to be in a doubly engaged position; S13) Determine if the vehicle is turned off or powered off. If yes, end; if no, return to step S11). S2: Control steps for the air spring in normal operating mode: S21) Displacement of the output plate push rod To begin, the pedal mode is first read to determine the "ped displacement-feedback force curve"; S22) Read ; S23) Based on the "pedal displacement-feedback force curve" and Determine the target air pressure ; S24) Read the air pressure of the air spring. ; S25) Judgment If yes, proceed to the next step sequentially; if no, the valve port AB of the four-position four-way solenoid valve is connected, the air spring is depressurized, and then the process jumps to step S28). S26) Judgment If yes, proceed to the next step; if no, the valve port A-none of the four-position four-way solenoid valve is connected, the air spring maintains pressure, and then proceed to step S28). S27) When the AC port of the four-position four-way solenoid valve is connected, the air spring pressurizes the valve. S28) Read ; S29) Judgment If yes, then end; if no, then return to S23). S3: Control steps for filling and discharging high-pressure gas cylinders under normal operating mode: S31) Read the target gas pressure of the gas cylinder ; S32) Read the gas cylinder pressure ; S33） ； S34) Judgment If yes, proceed to the next step; if no, proceed to S341). S341) Judgment If yes, proceed to S342); if no, end. S342) Start the air compressor; S343) Solenoid valve (10) AC is turned on for a period of time t, and then returns to S32). S35) Judgment If yes, then end; if no, return to S343). Where △p is the margin when filling the high-pressure gas cylinder.

7. The pedal feel simulation method with active redundancy and variable sensing function according to claim 6, characterized in that... It also includes a step in custom mode to fit a new "pedal travel-feedback force curve" based on the driver's selection: S41) Select two existing fixed pedal modes, M and N; S42) provides two percentages m and n for pedal modes M and N, where m and n must satisfy... Relationship; S43) Take the pedal displacement ; S44) Based on the "pedal travel-feedback force curve" stored in the ECU controller, take the... The pedal feedback force corresponding to M mode and N mode is as follows: and ; S45) Obtain the custom mode. Corresponding pedal feedback force : ； S46） ； S47) Judgment =max If yes, then end; if no, return to S43). in, The unit pedal displacement is manually set according to the actual situation. The percentages m and n can be input via the knob.

8. The pedal feel simulation method with active redundancy and variable sensing function according to claim 6, characterized in that... The pedal displacement-feedback force curve is a graph stored in the controller based on the relationship between pedal displacement and pedal feedback force. It includes two fixed modes and a custom mode where the pedal feedback force is between the feedback forces of the two fixed modes.

Images