A brake pedal feel simulator with dynamic feedback adjustment function

Abstract

The present application relates to the field of automobile brake-by-wire system, especially to a brake-by-wire pedal feeling simulator with dynamic feedback adjustment function, comprising a pedal push rod, multiple groups of pistons and springs, a lever mechanism, a motor, a gear reduction mechanism, a ball screw pair, an angle sensor, a displacement sensor and an electronic control unit (ECU). The simulator shortens the axial size by connecting the spring, the motor and the ball screw in parallel, eliminates the motion interference by means of the moving and rotating composite motion pair, dynamically adjusts the lever ratio, realizes mechanical redundancy by using the non-self-locking motor, and adopts the hierarchical adjustment mechanism of "mechanical basic feedback force and electrical fine adjustment". The core advantage lies in compact structure, accurate feedback, reliable failure protection and controllable cost, which solves the problems of existing simulator such as axial length, motion interference and insufficient safety. When the electronic control unit fails, the mechanical structure can still provide basic pedal feeling, ensuring driving safety.

Description

Technical Field

[0001] This invention relates to the field of automotive brake-by-wire systems, and more particularly to a brake-by-wire pedal feel simulator with dynamic feedback adjustment function. Background Technology

[0002] With the development of vehicle electrification and intelligence, intelligent chassis have gradually become an important direction for breakthroughs in the automotive industry. As the core of the chassis, the braking system not only affects overall vehicle performance but also directly impacts driving safety. In the intelligent chassis system, the brake-by-wire system is a key component. Compared to electro-pneumatic and electro-hydraulic braking systems, the electro-mechanical braking system completely eliminates hydraulic / pneumatic pipelines and components, using an electric motor as the power source. Through a distributed architecture where each wheel is independently controllable, it achieves precise execution of braking commands, significantly shortening braking response time and gradually becoming the development direction of brake-by-wire. However, because there is no longer a direct mechanical-hydraulic / pneumatic coupling between the brake pedal and the braking actuator, the driver lacks traditional foot feedback during pedaling, which can easily affect the driving experience and safety.

[0003] Currently, the mainstream technology in the industry is the electromagnetic hydraulic pedal feel simulator, which simulates the pedal force-displacement relationship through a hydraulic chamber, solenoid valve, and graded springs. Although the technology is mature and the pedal feel is close to that of traditional brakes, its inherent structure based on hydraulic medium and valve group control has core problems such as hydraulic leakage and high temperature sensitivity, resulting in poor pedal feel consistency and sluggish dynamic response. At the same time, most of these simulators do not have an independent mechanical redundancy feedback structure. When the electronic control or hydraulic circuit fails, the pedal feedback force is easily lost, which poses a driving safety hazard. Moreover, the overall structure is complex and it is difficult to balance the clearance between moving parts and frictional resistance, which directly affects the smoothness of pedal operation and the accuracy of force transmission.

[0004] To address the aforementioned issues, there is an urgent need to develop a pedal feel simulator that is hydraulically free, compact in structure, provides precise feedback, and has reliable mechanical redundancy, in order to meet the high-performance development and engineering application requirements of brake-by-wire systems. Summary of the Invention

[0005] The problem this invention aims to solve is to overcome the shortcomings of the prior art and provide a line-controlled brake pedal feel simulator with dynamic feedback adjustment function.

[0006] This invention is achieved through the following technical solution: A brake-by-wire pedal feel simulator with dynamic feedback adjustment function includes a pedal assembly, a simulator, and an electronic control unit (ECU). The pedal assembly is equipped with a displacement sensor and an angle sensor, both electrically connected to the ECU. The ECU is electrically connected to a motor. The pedal assembly includes a brake pedal and a pedal push rod, one end of which is hinged to the brake pedal. The simulator includes a cylinder, with a first piston and a second piston coaxially arranged within the cylinder. The other end of the pedal push rod is fixed to the first piston. A first spring and a second spring are mounted on the first and second pistons, respectively. The free length of the second spring is less than that of the first spring. The cylinder also includes a lever slide, with a lever mounted on both its upper and lower end faces. The second bearing and the second piston are symmetrically fixed with clamping rods, which are connected to the second bearing. The lever slide has horizontal through holes on its left and right sides, and linear bearings are installed in the through holes. The lever is assembled in the linear bearings, and one end of the lever is vertically fixed to the lever shaft. The third bearing is installed on the lever shaft, and the outer ring of the third bearing is fixed to the cylinder body. The end of the lever away from the lever shaft is fixed to a shift fork, which is a U-shaped frame with strip holes on both the upper and lower end faces. It also includes a ball screw pair, which is connected to the motor. The ball screw pair includes a screw nut and a ball screw. The ball screw is installed on the cylinder body through bearings. The outer circumference of the screw nut is fixed to a second sleeve. The upper and lower end faces of the second sleeve are provided with convex cylinders that pass through the strip holes and can slide left and right within the strip holes.

[0007] Furthermore, the brake pedal has a groove on the side facing the pedal push rod, the pedal slide is embedded in the groove and can slide along the groove, a pin is fixed to the end of the pedal slide away from the brake pedal, and first bearings are respectively assembled at both ends of the pin, the end of the pedal push rod facing the brake pedal is fixed to a U-shaped seat, and the first bearings are installed on both sides of the U-shaped seat.

[0008] Furthermore, the mating surface between the groove and the pedal slide is fitted with needle rollers.

[0009] Furthermore, the two ends of the first spring are respectively connected to the first piston and the second piston. A first sleeve is provided on the outer periphery of the first piston. The second spring is sleeved on the second piston and the first sleeve. One end of the second spring is fixed to the second piston, and the other end is a free end. There is a gap between the free end of the second spring and the first piston in the free state.

[0010] Furthermore, a first limiting device is provided on the cylinder body corresponding to the first piston, and a second limiting device is provided on the cylinder body corresponding to the second piston. Both the first limiting device and the second limiting device are rigid blocks.

[0011] Furthermore, the lever is provided with a rectangular protrusion at one end connected to the fork, and a rectangular groove matching the protrusion is provided on the end face of the fork. Both the rectangular protrusion and the rectangular groove are provided with corresponding through holes, and the lever and the fork are fixed together by bolts passing through the through holes.

[0012] Furthermore, the lead screw nut has a guide hole parallel to the ball screw, and the guide rod is coaxially inserted into the guide hole, with both ends of the guide rod fixedly connected to the cylinder body.

[0013] Furthermore, the output shaft of the motor is perpendicular to the ball screw, a small bevel gear is fixed to the upper end of the output shaft of the motor, and a large bevel gear is fixed to the end of the ball screw away from the shift fork, with the small bevel gear meshing with the large bevel gear.

[0014] Furthermore, the outer end of the strip hole is sealed by a U-shaped component, which is stuck at the outer end of the strip hole. The bolt passes through the strip hole and the U-shaped component, and nuts are provided at both ends of the bolt.

[0015] Furthermore, the motor is a non-self-locking motor.

[0016] Working principle of the invention: When the driver depresses the brake pedal, the pedal push rod drives the first piston to compress the spring, generating a basic feedback force. Displacement and angle sensors collect brake pedal displacement and applied force signals in real time and transmit them to the electronic control unit (ECU). The ECU calculates the required compensation feedback force based on a preset pedal force-displacement relationship curve and outputs a corresponding voltage command to the motor. The motor drives the large bevel gear to rotate via a small bevel gear, which in turn drives the ball screw to rotate, thereby pushing the screw nut to move axially. The screw nut drives the shift fork and lever to move via a second sleeve. The lever, in turn, drives the clamping rod to push the second piston to compress the spring, achieving precise compensation of the feedback force and ultimately synthesizing a target reaction force curve that meets the expectations.

[0017] The beneficial effects of this invention are: 1) This invention achieves parallel arrangement of spring assembly, motor, and ball screw transmission mechanism through lever mechanism, replacing the traditional series structure, greatly shortening the axial dimension of simulator and improving the overall vehicle integration adaptability.

[0018] 2) This invention employs a sliding groove and pedal slide joint structure at the hinge of the brake pedal and pedal push rod. The relative sliding friction between the sliding groove and the pedal slide is reduced by the needle roller, thereby reducing the operating resistance of the brake pedal. At the same time, the bearing-pin connection structure on the pedal slide is hinged to the pedal push rod, optimizing the force transmission efficiency, reducing mechanical wear, and completely solving the interference problem between circular motion and linear motion. It also allows the lever ratio to be dynamically adjusted with the brake pedal angle, improving the accuracy of feedback force calculation.

[0019] 3) The present invention assembles a second bearing on the upper and lower sides of the lever slide, and a linear bearing is assembled in the through hole of the lever slide, so that the lever slide can realize a combined rotation-translation motion on the lever, thereby coordinating the circumferential motion of the brake pedal and the linear motion of the pedal push rod, reducing the influence of friction and backlash on force transmission, and improving the accuracy and durability of force transmission.

[0020] 4) The feedback force of this invention is mainly provided by mechanical springs, and the motor is only used for fine adjustment compensation through ball screws and levers, which reduces the requirements for motor power and accuracy, while taking into account the feedback response speed and system cost.

[0021] 5) The motor is used. When the motor or electronic control system fails, the driver can still press the brake pedal normally. The first spring and the second spring are connected in parallel to provide basic feedback force to ensure driving safety. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of this embodiment; Figure 2 This is a schematic diagram of the overall structure after the cylinder block is removed in this embodiment; Figure 3 This is a schematic diagram of the structure from another angle in this embodiment; Figure 4 This is a schematic cross-sectional view of the overall structure of this embodiment; Figure 5 This is a schematic diagram of the signal connection at the brake pedal in this embodiment; Figure 6 This is an enlarged structural diagram of the brake pedal and pedal slide in this embodiment; Figure 7 This is an enlarged structural diagram of the lever slide in this embodiment; Figure 8 This is a schematic diagram of the fork and lever split structure in this embodiment; Figure 9 This is a schematic diagram of the ball screw pair structure in this embodiment; Figure 10 This is a schematic diagram of the shift fork structure in this embodiment.

[0023] In the diagram, 1. Brake pedal; 2. Needle roller; 3. Pedal slide; 4. First bearing; 5. Pedal push rod; 6. First limiting device; 7. First piston; 8. First sleeve; 9. First spring; 10. Second spring; 11. Second limiting device; 12. Second piston; 13. Clamping rod; 14. Lever shaft; 15. Lever slide; 16. Lever; 17. Linear bearing; 18. Shift fork; 19. Lead screw nut; 20. Support bearing; 21. Second sleeve; 2. Ball screw; 23. Guide rod; 24. Fixed bearing; 25. Small bevel gear; 26. Large bevel gear; 27. Motor; 28. Electronic control unit (ECU); 29. ​​Displacement sensor; 30. Angle sensor; 31. Third bearing; 32. Strip hole; 33. Convex cylinder; 34. Slide groove; 35. Pin; 36. U-shaped seat; 37. Rectangular protrusion; 38. Rectangular groove; 39. Through hole; 40. U-shaped part; 41. Cylinder block; 42. Second bearing. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0025] This embodiment includes a pedal assembly, a simulator, and an electronic control unit (ECU) 28. The pedal assembly is equipped with a displacement sensor 29 and an angle sensor 30, both electrically connected to the ECU 28. The ECU 28 is also electrically connected to a motor 27. The displacement sensor 29 collects real-time signals of the pedal displacement and speed of the brake pedal 1, while the angle sensor 30 collects real-time signals of changes in the pedal angle. Both sensors convert the collected signals into electrical signals and transmit them to the ECU 28. The ECU 28 calculates the desired feedback force based on the collected signals, thereby precisely controlling the speed and direction of the motor 27. The pedal assembly includes a brake pedal 1 and a pedal push rod 5, with one end of the push rod 5 hinged to the brake pedal 1. The simulator includes a cylinder 41, with a first piston 7 and a second piston 12 coaxially arranged within the cylinder 41. Both the first piston 7 and the second piston 12 can reciprocate along the axial direction of the cylinder 41. The other end of the pedal push rod 5 is fixedly connected to the first piston 7. An elastic component is provided between the first piston 7 and the second piston 12. The elastic component includes a first spring 9 and a second spring 10, wherein the free length of the second spring 10 is less than the free length of the first spring 9. The above structure is the existing brake pedal 1 structure, and will not be described in detail here. The improvements of this invention will be highlighted below: The cylinder body 41 of this invention is further provided with a lever mechanism, which includes a lever 16, a lever shaft 14, and a lever slide 15. The lever slide 15 has horizontal through holes on its left and right sides, and a linear bearing 17 is installed in each through hole. The lever 16 is assembled inside the linear bearing 17, and the linear bearing 17 can slide along the lever 16. One end of the lever 16 is vertically fixed to the lever shaft 14, which is a vertical shaft. A third bearing 31 is assembled on the lever shaft 14. The outer ring of the third bearing 31 is fixed to the cylinder body 41, and the inner ring of the third bearing 31 is rotatable. The lever shaft 14 can rotate together with the inner ring of the third bearing 31, thereby causing the lever 16 to swing. The lever slide 15 has cylinders on both its upper and lower end faces, each bearing a second bearing 42. The cylinders are fixedly connected to the inner rings of the second bearings 42. Clamping rods 13 are symmetrically fixed above and below the second piston 12, each corresponding to a different bearing 42. The clamping rods 13 are rotatably connected to the second bearings 42 and fixedly connected to their outer rings. The inner rings of the second bearings 42 are rotatable, allowing the lever slide 15 and the inner rings of the second bearings 42 to rotate together. A shift fork 18 is fixedly connected to the end of the lever 16 furthest from the lever shaft 14. The shift fork 18 is a U-shaped frame with slotted holes 32 on both its upper and lower end faces. A ball screw assembly is also located at the shift fork 18, positioned on the right side of the cylinder body 41. This ball screw assembly is connected to a motor 27, which provides rotational power to the ball screw assembly. The ball screw assembly includes a screw nut 19 and a ball screw 22. The ball screw 22 is mounted on the cylinder 41 via bearings. Both ends of the ball screw 22 are mounted on the cylinder 41 via a support bearing 20 and a fixed bearing 24, respectively. The support bearing 20 is located on the side closer to the shift fork 18. The initial position of the screw nut 19 is near the end of the support bearing 20. The ball screw 22 is perpendicular to the lever 16. The outer circumference of the screw nut 19 is coaxially fixed to a second sleeve 21. The upper and lower end faces of the second sleeve 21 are provided with radially protruding convex cylinders 33. The diameter of the convex cylinders 33 is equal to the width of the strip hole 32. The upper and lower convex cylinders 33 pass through the upper and lower strip holes 32 of the shift fork 18, respectively. The convex cylinders 33 can slide left and right within the strip hole 32. The aforementioned ball screw pair and motor 27 are arranged in the right side region of the cylinder 41, while the piston (first piston 7 and second piston 12) and elastic components (first spring 9 and second spring 10) are arranged in the left side region of the cylinder 41. The two are arranged in parallel left and right through a lever mechanism and shift fork 18, replacing the traditional series layout, which greatly shortens the overall axial dimension of the simulator, reduces the installation space requirements of the whole vehicle, and makes the engineering adaptability and applicability stronger.Displacement sensor 29 and angle sensor 30 convert the real-time collected displacement and angle signals into electrical signals and transmit them to electronic control unit ECU 28. ECU 28 has multiple preset pedal force-displacement relationship curves adapted to different driving scenarios. ECU 28 calculates the desired feedback force based on the transmitted signals and outputs control commands to motor 27, thereby precisely controlling the speed and direction of motor 27. Through the transmission of lever 16 and shift fork 18, the feedback force of brake pedal 1 is dynamically adjusted, so that the feedback force curve is highly consistent with the traditional hydraulic braking system, improving the real experience of pedal feel.

[0026] In the above-described preferred embodiment, a bevel gear transmission mechanism is used for transmission. The motor 27 is mounted on the cylinder 41, and the output shaft of the motor 27 is perpendicular to the ball screw 22. A small bevel gear 25 is coaxially fixed to the upper end of the output shaft of the motor 27, and a large bevel gear 26 is coaxially fixed to the end of the ball screw 22 away from the shift fork 18. The small bevel gear 25 and the large bevel gear 26 mesh and transmit power. This embodiment uses an orthogonal bevel gear mechanism. When the motor 27 is working, the small bevel gear 25 rotates, causing the large bevel gear 26 to rotate as well. The large bevel gear 26 rotates, causing the ball screw 22 to rotate, thereby causing the screw nut 19 and the second sleeve 21 to move along the ball screw 22, which in turn moves the shift fork 18. Since the shift fork 3518 is fixed to the lever 16, the lever shaft 14 rotates, causing the lever 16 to swing. The lever slide 15 slides along the lever 16 and swings with it. The inner ring of the second bearing 42 rotates, and the lever slide 15 drives the second piston 12 to move via the clamping rod 13. In this embodiment, lever 16 and shift fork 18 are used to form a proportional transmission structure. The torque output by motor 27 is transmitted to shift fork 18 through gear reduction mechanism and ball screw 22. The force is proportionally amplified by the swing of lever 16 and then transmitted to second piston 12 through clamp rod 13 to adjust spring compression. A small torque motor 27 can achieve precise adjustment of large feedback force, which greatly reduces the power, torque and precision performance requirements of motor 27, simplifies motor 27 selection and effectively controls the overall system cost.

[0027] In the above-described further preferred embodiment, guide holes parallel to the ball screw 22 are provided on the lead screw nut 19 and the second sleeve 21. A guide rod 23 is coaxially inserted into the guide hole, and both ends of the guide rod 23 are fixedly connected to the cylinder body 41. The guide rod 23 is used to limit the circumferential rotation of the lead screw nut 19, ensuring that the lead screw nut 19 can only move linearly along the axial direction. This avoids jamming or transmission offset problems caused by circumferential deflection of the lead screw nut 19 during transmission, and improves the transmission accuracy and smoothness of the electronic control compensation force.

[0028] In the above, as a further preferred embodiment, the fixing structure of lever 16 and fork 18 is preferably as follows: a rectangular protrusion 37 is provided at one end of lever 16 and fork 18, and a rectangular groove 38 matching the protrusion is provided on the end face of fork 18. The rectangular protrusion 37 is inserted into the rectangular groove 38. At the same time, both the rectangular protrusion 37 and the rectangular groove 38 are provided with corresponding through holes 39. The lever 16 and fork 18 are fixed together by bolts passing through the through holes 39.

[0029] In the above-described further preferred embodiment, a first limiting device 6 is provided on the cylinder body 41 corresponding to the first piston 7, and a second limiting device 11 is provided on the cylinder body 41 corresponding to the second piston 12. Both the first limiting device 6 and the second limiting device 11 are rigid stops, integrally formed with the cylinder body 41. The first limiting device 6 is used to limit the return limit stroke of the first piston 7, and the second limiting device 11 is used to limit the compression limit stroke of the second piston 12, avoiding overpressure deformation of the spring and jamming caused by excessive movement of the mechanism, while eliminating the wobble of the fitting clearance at the limit position of the components, ensuring the reliability of the device operation and the consistency of the foot feel feedback.

[0030] In the above, the preferred arrangement of the elastic component consisting of the first spring 9 and the second spring 10 is as follows: the first spring 9 and the second spring 10 are coaxially fitted between the first piston 7 and the second piston 12. The two ends of the first spring 9 are respectively connected to the first piston 7 and the second piston 12. A first sleeve 8 is fitted around the outer periphery of the first piston 7 to separate the first spring 9 and the second spring 10. The second spring 10 is fitted on the second piston 12 and the first sleeve 8. One end of the second spring 10 is fixed to the second piston 12, and the other end is a free end. There is a gap between the free end of the second spring 10 and the first piston 7 in the free state. Since the free length of the second spring 10 is less than the free length of the first spring 9, when the circuit fails, the pedal force of the brake pedal 1 is transmitted to the first piston 7 through the pedal push rod 5, pushing the first piston 7 to first compress the first spring 9 to generate an initial feedback force. As the pedal displacement increases, the first piston 7 contacts and compresses the second spring 10. The parallel elastic force of the first spring 9 and the second spring 10 provides a nonlinear basic braking feedback force, realizing the mechanical redundancy protection of the device and meeting the basic pedal feel requirements in the failure state.

[0031] In the above, as a further preferred embodiment, for ease of disassembly and assembly, the outer end of the strip hole 32 of the shift fork 18 is blocked by a U-shaped piece 40. The U-shaped piece 40 is locked at the outer end of the strip hole 32, and the bolt passes through the strip hole 32 and the U-shaped piece 40. Nuts are provided at both ends of the bolt.

[0032] The present invention also improves the connection method between the brake pedal 1 and the pedal push rod 5, as follows: The brake pedal 1 is provided with a groove 34 on the side facing the pedal push rod 5, the pedal slide 3 is embedded in the groove 34 and can slide along the groove 34, the mating surface of the groove 34 and the pedal slide 3 is fitted with a needle roller 2, the end of the pedal slide 3 away from the brake pedal 1 is fixedly connected to a pin 35, the two ends of the pin 35 are respectively equipped with first bearings 4, the end of the pedal push rod 5 facing the brake pedal 1 is fixedly connected to a U-shaped seat 36, the first bearings 4 are installed on both sides of the U-shaped seat 36, the outer ring of the first bearing 4 is fixedly connected to the U-shaped seat 36, the inner ring of the first bearing 4 is fixedly connected to the pin 35, the inner ring of the first bearing 4 can rotate, and the pin 35 and the pedal slide 3 rotate together with the inner ring. The improved structure not only completely solves the motion interference problem between the circumferential rotation of the brake pedal 1 and the linear motion of the pedal push rod 5, but also eliminates the fit clearance between the needle roller 2 and the first bearing 4, preventing the brake pedal 1 from shaking during the pressing process. At the same time, it reduces the relative motion friction resistance, ensuring the smooth operation of the brake pedal 1 and the authenticity of the foot feel feedback.

[0033] In this embodiment, the preferred motor 27 is a non-self-locking motor. When the motor 27 or the electronic control unit ECU 28 experiences a circuit failure, the output shaft of the motor 27 can rotate freely, driving the small bevel gear 25, the large bevel gear 26 and the ball screw 22 to rotate freely without jamming. This avoids the transmission components of the motor 27 interfering with the pedaling action of the brake pedal 1, ensuring the normal pedaling stroke of the brake pedal 1 and providing basic failure safety protection for the device.

[0034] The specific working process of this embodiment is as follows: Initial state: The first piston 7 abuts against the first limiting device 6 under the preload of the first spring 9, the lead screw nut 19 is in the initial position close to the support bearing 20, and the second piston 12 and the second limiting device 11 maintain a preset distance.

[0035] Basic feedback stage: When the driver presses the brake pedal 1, the circular motion of the brake pedal 1 causes the pedal slide 3 in the slide groove 34 to slide. At the same time, the pedal push rod 5 is driven to make linear motion through the pin 35, pushing the first piston 7 to compress the first spring 9. When the brake pedal 1 is in the initial stage of displacement, only the first spring 9 provides feedback force, simulating the free travel and initial foot feel of the traditional braking system.

[0036] Compensation and adjustment phase: When the brake pedal 1 displacement exceeds the initial stage threshold, the first piston 7 contacts the second spring 10 and begins to compress together. At the same time, the displacement sensor 29 and the angle sensor 30 transmit signals to the electronic control unit ECU 28. The electronic control unit ECU 28 calculates the compensation force according to the preset curve (different feedback force growth rates correspond to low-intensity braking and medium-high-intensity braking). If the actual feedback force is less than the expected feedback force, the electronic control unit ECU 28 controls the motor 27 to rotate forward, driving the ball screw 22 to push the second sleeve 21 and the screw nut 19 forward, increasing the compression of the second spring 10 through the lever mechanism, and improving the feedback force. If the actual feedback force is greater than the expected feedback force, the motor 27 rotates in reverse, releasing part of the compression and reducing the feedback force.

[0037] Failure protection phase: When the electronic control unit ECU28 detects a fault in motor 27 or an abnormal sensor signal, it automatically switches to mechanical redundancy mode. After the motor 27 is powered off, it rotates freely. When the driver presses the brake pedal 1, the feedback force is provided only by the first spring 9 and the second spring 10. The feedback force and the displacement of the brake pedal 1 have a non-linear relationship, which meets the basic braking operation requirements.

[0038] Reset phase: When the driver releases the brake pedal 1, the reset force of the first spring 9 and the second spring 10 pushes the first piston 7, the second piston 12 and the pedal push rod 5 back to the initial position. The motor 27 reverses under the control of the electronic control unit ECU 28, driving the lead screw nut 19 back to the initial position, ready for the next braking operation.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can still be made to the technical solutions described in the above embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A brake pedal feel simulator with dynamic feedback adjustment function, comprising a pedal assembly, a simulator, and an electronic control unit (ECU) (28), wherein a displacement sensor (29) and an angle sensor (30) are mounted on the pedal assembly, both the displacement sensor (29) and the angle sensor (30) are electrically connected to the electronic control unit (ECU) (28), and the electronic control unit (ECU) (28) is electrically connected to a motor (27); the pedal assembly comprises a brake pedal (1) and a pedal push rod (5), one end of the pedal push rod (5) is hinged to the brake pedal (1); the simulator comprises a cylinder (41), a first piston (7) and a second piston (12) are coaxially arranged in the cylinder (41), the other end of the pedal push rod (5) is fixedly connected to the first piston (7), and a first spring (9) and a second spring (10) are provided on the first piston (7) and the second piston (12), wherein the free length of the second spring (10) is less than the free length of the first spring (9), characterized in that: The cylinder (41) is also provided with a lever slide (15). A second bearing (42) is installed on both the upper and lower end faces of the lever slide (15). A clamping rod (13) is symmetrically fixed on the upper and lower ends of the second piston (12). The clamping rod (13) is connected to the second bearing (42). A horizontal through hole is provided on the left and right sides of the lever slide (15). A linear bearing (17) is installed in the through hole. A lever (16) is assembled in the linear bearing (17). One end of the lever (16) is vertically fixed to the lever shaft (14). A third bearing (31) is installed on the lever shaft (14). The outer ring of the third bearing (31) is fixed on the cylinder (41). The lever (16) The end away from the lever shaft (14) is fixedly connected to the shift fork (18). The shift fork (18) is a U-shaped frame. The upper and lower end faces of the shift fork (18) are provided with strip holes (32). It also includes a ball screw pair. The ball screw pair is connected to the motor (27). The ball screw pair includes a screw nut (19) and a ball screw (22). The ball screw (22) is mounted on the cylinder body (41) through a bearing. The outer periphery of the screw nut (19) is fixedly connected to the second sleeve (21). The upper and lower end faces of the second sleeve (21) are provided with convex cylinders (33). The convex cylinders (33) pass through the strip holes (32) and can slide left and right in the strip holes (32).

2. The drive-by-wire brake pedal feel simulator with dynamic feedback adjustment function according to claim 1, characterized in that: The brake pedal (1) has a groove (34) on the side facing the pedal push rod (5). The pedal slide (3) is embedded in the groove (34) and can slide along the groove (34). A pin (35) is fixed to the end of the pedal slide (3) away from the brake pedal (1). The two ends of the pin (35) are respectively equipped with first bearings (4). The end of the pedal push rod (5) facing the brake pedal (1) is fixed to a U-shaped seat (36). The first bearings (4) are installed on both sides of the U-shaped seat (36).

3. The drive-by-wire brake pedal feel simulator with dynamic feedback adjustment function according to claim 2, characterized in that: The groove (34) and the pedal slide (3) are fitted with needle rollers (2).

4. The drive-by-wire brake pedal feel simulator with dynamic feedback adjustment function according to claim 1, 2, or 3, characterized in that: The first spring (9) is connected to the first piston (7) and the second piston (12) at both ends respectively. A first sleeve (8) is provided on the outer periphery of the first piston (7). The second spring (10) is sleeved on the second piston (12) and the first sleeve (8). One end of the second spring (10) is fixed to the second piston (12) and the other end is a free end. There is a gap between the free end of the second spring (10) in the free state and the first piston (7).

5. The drive-by-wire brake pedal feel simulator with dynamic feedback adjustment function according to claim 1, 2, or 3, characterized in that: The cylinder (41) is provided with a first limiting device (6) corresponding to the first piston (7), and the cylinder (41) is provided with a second limiting device (11) corresponding to the second piston (12). The first limiting device (6) and the second limiting device (11) are both rigid blocks.

6. The drive-by-wire brake pedal feel simulator with dynamic feedback adjustment function according to claim 1, 2, or 3, characterized in that: The lever (16) is connected to the fork (18) at one end with a rectangular protrusion (37). The end face of the fork (18) is provided with a rectangular groove (38) that matches the protrusion. Both the rectangular protrusion (37) and the rectangular groove (38) are provided with corresponding through holes (39). The lever (16) and the fork (18) are fixed together by bolts passing through the through holes (39).

7. The brake-by-wire pedal feel simulator with dynamic feedback adjustment function according to claim 1, 2, or 3, characterized in that: The lead screw nut (19) has a guide hole parallel to the ball screw (22), and the guide rod (23) is coaxially inserted in the guide hole. Both ends of the guide rod (23) are fixedly connected to the cylinder body (41).

8. The brake-by-wire pedal feel simulator with dynamic feedback adjustment function according to claim 1, 2, or 3, characterized in that: The output shaft of the motor (27) is perpendicular to the ball screw (22). The upper end of the output shaft of the motor (27) is fixedly connected to a small bevel gear (25), and the end of the ball screw (22) away from the shift fork (18) is fixedly connected to a large bevel gear (26). The small bevel gear (25) meshes with the large bevel gear (26).

9. The brake-by-wire pedal feel simulator with dynamic feedback adjustment function according to claim 1, 2, or 3, characterized in that: The outer end of the strip hole (32) is blocked by a U-shaped part (40). The U-shaped part (40) is stuck at the outer end of the strip hole (32). The bolt passes through the strip hole (32) and the U-shaped part (40). Nuts are provided at both ends of the bolt.

10. The brake-by-wire pedal feel simulator with dynamic feedback adjustment function according to claim 1, 2, or 3, characterized in that: The motor (27) is a non-self-locking motor.

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