Pedal force adjustable brake pedal apparatus and method

Abstract

The application discloses a brake pedal device and method with adjustable pedal force, and relates to the field of automobile braking. The device comprises a pedal base and a pedal arm. The pedal arm is connected with the pedal base through a central rotating shaft, and one end of the central rotating shaft is connected with a driving assembly. The driving assembly comprises a motor installed in a shell and a gear transmission mechanism connected with the motor. The motor is connected with an electronic control unit, and the electronic control unit is connected with a wire control controller. The electronic control unit is used for collecting stroke signals or pressure signals output by the wire control controller, controlling the motor to rotate in the positive direction according to the collected signals to adjust the pedal force, and controlling the motor to rotate in the reverse direction to drive the pedal arm to return to the original position when the pedal returns to the original position. The application can solve the problems that the existing pedal relies on the passive reset force of the spring during the returning process, the returning speed is not adjustable, and the pedal rebounds and collides when returning to the end of the initial position.

Description

Technical Field

[0001] This invention relates to the field of automotive braking, and more particularly to a brake pedal device and method with adjustable pedal force. Background Technology

[0002] Currently, the pedal force of automotive brake pedals is typically provided by a fixed-stiffness return spring or a fixed-damping pedal simulator. This pedal force cannot be adjusted according to driver habits or driving modes, making it difficult to meet the needs of different scenarios such as comfort and sportiness. Existing brake-by-wire systems use passive pedal simulators where the pedal feel is fixed by the hardware structure; changing the feel requires replacing the hardware, resulting in poor versatility. Furthermore, after releasing the pedal, the return process relies on the passive restoring force of the spring, and the return rate is not adjustable.

[0003] For example, existing technology discloses a brake pedal with simulated foot feel, in which a servo motor is mounted with gears that mesh with the teeth of an electronic booster push rod. By changing the input current of the servo motor, the resisting torque on the push rod is changed, thereby simulating different pedal feel. However, in this solution, the pedal return still relies on a return spring sleeved on the rotating shaft to provide a passive reset force, and the pedal return rate is not adjustable. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a brake pedal device and method with adjustable pedal force, which can solve the problems of existing pedals relying on the passive reset force of springs during the return process, having an unadjustable return rate, and experiencing rebound impact when the pedal returns to the end of the initial position.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, embodiments of the present invention provide a brake pedal device with adjustable pedal force, including a pedal base and a pedal arm. The pedal arm is connected to the pedal base via a central rotating shaft, and one end of the central rotating shaft is connected to a drive assembly. The drive assembly includes a motor installed in a housing and a gear transmission mechanism connected to the motor. The motor is connected to an electronic control unit, which is connected to a drive-by-wire controller. The electronic control unit is used to collect stroke signals or pressure signals output by the drive-by-wire controller, control the motor to rotate forward according to the collected signals to adjust the pedal force, and control the motor to rotate in reverse when the pedal returns to its original position to drive the pedal arm to return to its original position.

[0006] As a further implementation, the gear transmission mechanism adopts a multi-stage planetary gear structure.

[0007] As a further implementation, the gear transmission mechanism includes a large gear and a small gear that mesh with each other, the large gear being mounted on a central rotating shaft and the small gear being mounted on the output shaft of a motor.

[0008] As a further implementation, the housing is fixed to one side of the pedal base; The central rotating shaft is interference-fitted with the pedal base via a bearing.

[0009] As a further implementation, the electronic control unit determines the target pedal force based on the vehicle driving mode, which includes at least comfort mode, standard mode, and sport mode.

[0010] As a further implementation, in comfort mode, the target pedal force is set to a first target pedal force, and the electronic control unit controls the motor to output a first torque; in standard mode, the target pedal force is set to a second target pedal force, and the electronic control unit controls the motor to output a second torque; in sport mode, the target pedal force is set to a third target pedal force, and the electronic control unit controls the motor to output a third torque. Wherein, the first target pedal force is less than the second target pedal force, the second target pedal force is less than the third target pedal force, the first torque is less than the second torque, and the second torque is less than the third torque.

[0011] As a further implementation, when the pedal arm returns to its initial position, the electronic control unit controls the motor to apply a damping torque to the central shaft in the opposite direction to the rotation of the pedal arm.

[0012] As a further implementation, a limiting stop block is provided on the outer side of the pedal base, and the limiting stop block is located at the end of the rotation stroke when the pedal arm returns to the initial position.

[0013] As a further implementation, the contact surface of the limiting stop block is provided with an elastic buffer layer.

[0014] Secondly, embodiments of the present invention also provide a control method for a brake pedal device with adjustable pedal force, comprising: The electronic control unit (ECU) acquires the stroke signal or pressure signal output by the drive-by-wire controller; the ECU determines the target pedal force according to the vehicle driving mode or preset parameters, controls the motor to rotate forward, drives the central shaft to rotate through the gear transmission mechanism, and adjusts the rotational torque applied to the pedal arm so that the pedal force matches the target pedal force; When the pedal returns to its original position, the electronic control unit controls the motor to reverse, which drives the central rotating shaft to rotate in the direction of the initial position via the gear transmission mechanism. This actively drives the pedal arm to rotate in the direction of the initial position, and dynamically adjusts the output torque of the motor to control the return rate according to the driving mode or preset parameters. When the pedal arm returns to its initial position, the electronic control unit controls the motor to apply a damping torque to the central shaft via a gear transmission mechanism, which is opposite to the direction of pedal arm rotation, to suppress the pedal arm's rebound impact.

[0015] The beneficial effects of this invention are as follows: The present invention relates to an adjustable brake pedal device, wherein the pedal arm is connected to the pedal base via a central rotating shaft, one end of which is connected to a drive assembly consisting of a motor and a gear transmission mechanism. The electronic control unit acquires the stroke signal or pressure signal output by the wire-controlled controller, controls the motor to rotate forward to apply a rotational torque to the central rotating shaft, thereby adjusting the pedal force, and controls the motor to rotate in reverse when the pedal returns to its original position to actively drive the pedal arm back to its original position. This enables the electronic control unit to continuously adjust the output torque of the motor through a current control closed loop, thereby achieving continuous adjustment of the pedal force and overcoming the shortcomings of existing fixed stiffness return springs or fixed damping pedal simulators that cannot dynamically adjust the pedal force. The electronic control unit uses the stroke signal or pressure signal from the drive-by-wire controller as the control input, balancing hardware cost control and signal reliability without the need for additional pedal-side sensors. When the pedal returns to its original position, the motor actively reverses to drive the pedal arm to reset. The return rate can be dynamically adjusted according to the driving mode or preset parameters, overcoming the problem of a fixed and unadjustable return rate. When the pedal arm returns to near the end of its initial position, the electronic control unit switches the motor control target to end damping torque, applying a damping torque to the central shaft in the opposite direction to the pedal arm's rotation, so that the pedal arm decelerates smoothly to its initial position, suppressing rebound impact noise and improving the overall NVH performance of the vehicle. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a schematic diagram of the brake pedal device according to one or more embodiments of the present invention; Figure 2 This is a schematic diagram of the installation of the pedal arm and pedal base according to one or more embodiments of the present invention; Figure 3 This is a schematic diagram of the installation of the limiting stop block according to one or more embodiments of the present invention.

[0018] The components include: 1. pedal base, 2. pedal arm, 3. central pivot, 4. bearing, 5. housing, 6. electrical control unit, 7. gear transmission mechanism, 8. motor, and 9. limit stop block. Detailed Implementation

[0019] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] Example 1: In existing brake pedal designs, pedal force is typically provided by a return spring with fixed stiffness or a pedal simulator with fixed damping. The spring stiffness and damping coefficient remain fixed after assembly, making it impossible to dynamically adjust the pedal force based on vehicle driving modes or driver habits. Regarding pedal return, existing solutions rely on a return spring to provide passive reset force. The return rate is determined by both the spring stiffness and the pedal arm's moment of inertia, and similarly remains fixed after assembly, making it impossible to adjust according to driving modes or market demands.

[0021] To address the aforementioned issues, this embodiment provides a brake pedal device with adjustable pedal force. The motor 8, via a gear transmission mechanism 7, acts on the central rotating shaft 3 with rotational torque to achieve active adjustment of the pedal force. When the pedal returns to its original position, the motor reverses to actively drive the pedal arm to reset, and the return rate can be dynamically adjusted according to the driving mode. When the pedal arm 2 returns to its initial position, the motor 8 provides a damping torque to suppress rebound impact.

[0022] In this embodiment, the motor 8, via the gear transmission mechanism 7, directly acts on the central rotating shaft 3 with rotational torque. The actuation point for pedal force adjustment is set at the rotation axis of the pedal arm 2, and the force application path is the rotational torque transmission path, resulting in a compact structure. The magnitude of the rotational torque can be continuously adjusted by the continuous control of the output torque of the motor 8 by the electronic control unit 6. The electronic control unit 6 uses the travel signal or pressure signal from the drive-by-wire controller, eliminating the need for an additional position sensor on the pedal side, thus reducing hardware costs while ensuring signal reliability. When the pedal returns to its original position, the motor 8 actively reverses to drive the pedal arm to reset, and the return rate can be dynamically adjusted according to the driving mode. When the pedal arm 2 returns to its initial end position, the motor 8 provides damping torque.

[0023] Specifically, refer to Figure 1 and Figure 2 The adjustable brake pedal device includes a pedal base 1, a pedal arm 2, a central rotating shaft 3, a housing 5, an electronic control unit 6, a gear transmission mechanism 7, a motor 8, etc. The pedal base 1 is the mounting base of the entire device, and its structure matches the mounting interface of the vehicle cab. It is fixed to the pedal mounting area of ​​the vehicle cab by bolts or welding.

[0024] One end of the pedal arm 2 is connected to the pedal base 1 via a central rotating shaft 3. The pedal arm 2 can rotate relative to the pedal base 1 around the axis of the central rotating shaft 3. When the pedal arm 2 is pressed, it rotates around the central rotating shaft 3 in the braking direction. After the pedal arm 2 is released, it rotates back to its initial position under the active drive of the motor 8. The pedal arm 2 serves as the carrier for the input of pedal force and the output of rotational torque. Its rotational axis coincides with the axis of the central rotating shaft 3. The rotational torque output by the gear transmission mechanism 7 is transmitted to the pedal arm 2 via the central rotating shaft 3, so that the pedal arm 2 exhibits resistance characteristics that are adapted to the target pedal force during the pressing process.

[0025] The central rotating shaft 3 extends along the rotation axis of the pedal arm 2. The central rotating shaft 3 is interference-fitted with the pedal base 1 via a bearing 4. The bearing 4 is press-fitted into the corresponding mounting hole of the pedal base 1, ensuring stable rotational support for the central rotating shaft 3 relative to the pedal base 1. The central rotating shaft 3 can rotate freely around its own axis under the support of the bearing 4. The interference fit of the bearing 4 ensures the assembly accuracy between the central rotating shaft 3 and the pedal base 1, preventing axial movement of the central rotating shaft 3 and ensuring the coaxiality of the spline fit between the output end of the gear transmission mechanism 7 and the central rotating shaft 3, thereby guaranteeing the stable transmission of rotational torque.

[0026] The pedal arm 2 is fitted onto the central rotating shaft 3 via a bushing. The pedal arm 2 and the central rotating shaft 3 are rotated together by the bushing. The bushing reduces the direct friction between the pedal arm 2 and the central rotating shaft 3, and also protects the outer surface of the central rotating shaft 3.

[0027] In this embodiment, the splined shaft section of the central rotating shaft 3 is fitted with the splined hole at the output end of the gear transmission mechanism 7, and the two form a torque transmission connection in the circumferential direction; the pedal arm 2 is fixed on the central rotating shaft 3, so that the rotational torque output by the gear transmission mechanism 7 can be transmitted to the pedal arm 2 through the central rotating shaft 3, and a rotational torque is applied to the pedal arm 2, thereby adjusting the pedal force.

[0028] When the electronic control unit 6 is powered off or malfunctions, the splined connection between the large gear and the central shaft 3 still exists. The central shaft 3 maintains a mechanical connection with the gear transmission mechanism 7 through the splined connection. This mechanical connection can provide a certain rotational resistance to the central shaft 3, i.e., basic feedback force, so that the pedal arm 2 can still feel a certain pedal force when the power is off, ensuring the initial pedal travel, meeting the braking safety requirements, and overcoming the defect of the pure electronic control scheme losing pedal feedback force when the power is off.

[0029] Reference Figure 1 and Figure 2The housing 5 is fixed to one side of the pedal base 1, and the housing 5 and the pedal base 1 are fixed by bolts or snap-fit ​​connections. The fixed position of the housing 5 matches the mounting interface of the pedal base 1, ensuring that the output end of the gear transmission mechanism 7 inside the housing 5 can remain coaxial with the central rotating shaft 3 on the pedal base 1, thereby ensuring the assembly accuracy of the spline fit.

[0030] Motor 8 is installed inside housing 5. The output shaft of motor 8 is connected to the input end of gear transmission mechanism 7. The rotational torque output by motor 8 is transmitted to central shaft 3 after being reduced and amplified by gear transmission mechanism 7. At the same time, electronic control unit 6 is installed inside housing 5 and is electrically connected to motor 8. It is used to control the direction of motor 8 and output torque according to the collected stroke signal or pressure signal.

[0031] In this embodiment, the housing 5 integrates the motor 8, gear transmission mechanism 7 and electronic control unit 6 into an independent modular assembly, which can be installed as a whole on the side of the pedal base 1 without modifying the basic structure of the pedal base 1 and pedal arm 2, thus reducing the complexity of assembly and maintenance.

[0032] Combination Figure 2 In this embodiment, the gear transmission mechanism 7 includes a large gear and a small gear that mesh with each other. The small gear is mounted on the output shaft of the motor 8, and the large gear is mounted on the splined shaft section of the central rotating shaft 3. The terms "large gear" and "small gear" are relative concepts, and the specific dimensions of the gears are determined according to actual installation requirements.

[0033] The pinion is connected to the output shaft of motor 8. When motor 8 rotates, the pinion and the large gear mesh with each other. Since the large gear has more teeth than the pinion, when the pinion drives the large gear to rotate, the transmission process achieves speed reduction and torque increase. The output speed of the large gear is lower than the input speed of the pinion, while the output torque of the large gear is higher than the input torque of the pinion.

[0034] Furthermore, the central hole of the large gear is a spline hole, which is fitted onto the spline shaft section of the central rotating shaft 3. The large gear and the central rotating shaft 3 form a torque transmission connection with spline engagement in the circumferential direction. The rotational torque output by the large gear is directly transmitted to the central rotating shaft 3 through the spline engagement, thereby applying rotational torque to the pedal arm 2 and realizing the adjustment of the pedal force.

[0035] Understandably, in other embodiments, the gear transmission mechanism 7 may adopt a multi-stage planetary gear structure, which includes multiple sets of meshing large and small gears. Each stage of the gear set is connected in series, and each stage of transmission achieves a certain reduction in speed and torque increase, thus achieving a large overall transmission ratio within a relatively small gear size range. By selecting gear combinations with different numbers of stages and gear ratios at each stage, the device can be adapted to the different requirements of different vehicle models for pedal feedback force without replacing the motor 8.

[0036] For vehicles with high pedal feedback force requirements, a multi-stage planetary gear structure with a large total transmission ratio can be selected, so that the motor 8 drives the central shaft 3 with a small output torque to generate a large rotational torque, thus meeting the pedal force requirements of the vehicle. For vehicles with low pedal feedback force requirements, a gear structure with a small total transmission ratio can be selected, so that the device can be adapted to the pedal force requirements of the vehicle with the same motor 8 configuration, thereby improving the versatility of the device.

[0037] In this embodiment, the electronic control unit 6 acquires the stroke signal or pressure signal output by the drive-by-wire controller, and the two signals can be redundantly verified. The electronic control unit 6 communicates with the drive-by-wire controller via a signal line, reusing the sensor signals of the drive-by-wire controller, eliminating the need to add an additional position sensor on the pedal side. The drive-by-wire controller outputs two independent signals, a stroke signal and a pressure signal, respectively. The electronic control unit 6 receives the stroke signal and the pressure signal and compares and verifies the two signals.

[0038] In some implementations, the electronic control unit 6 determines the target pedal force based on the vehicle's driving mode, which includes at least a comfort mode, a standard mode, and a sport mode. In comfort mode, the target pedal force is set as a first target pedal force, corresponding to a lighter pedal application effort, suitable for low-speed urban driving or driving scenarios where pedal force is sensitive. The electronic control unit 6 controls the motor 8 to output a first torque.

[0039] In standard mode, the target pedal force is set to the second target pedal force, corresponding to the pedal force level under normal driving habits. The electronic control unit 6 controls the motor 8 to output the second torque. In sport mode, the target pedal force is set to the third target pedal force, corresponding to a heavier pedal pressing force, to provide clear pedal force feedback. This is suitable for high-speed driving or driving scenarios that pursue a sense of driving control. The electronic control unit 6 controls the motor 8 to output the third torque.

[0040] Among these parameters, the first target pedal force is less than the second target pedal force, the second target pedal force is less than the third target pedal force, the first torque is less than the second torque, and the second torque is less than the third torque. The target pedal force for each driving mode can be written into the preset parameter table of the electronic control unit 6 through vehicle calibration. The electronic control unit 6 obtains the target pedal force by looking up the table according to the current driving mode signal, and determines the target output torque of the motor 8 accordingly. It then adjusts the actual output torque of the motor 8 through a current control closed loop to make the pedal force follow the target value.

[0041] The aforementioned correspondence between driving modes and target pedal force allows the same device to switch pedal force characteristics between different driving modes without replacing any hardware, overcoming the drawback of existing passive pedal simulators that require hardware replacement to change pedal feel characteristics. The switching of driving modes is triggered by a signal from the vehicle controller. Upon receiving a new driving mode signal, the electronic control unit 6 immediately updates the target pedal force lookup table result and adjusts the actual output torque of the motor 8 to the target value corresponding to the new mode through a current control closed loop. The entire switching process is highly responsive.

[0042] In some implementations, when the pedal arm 2 returns to its initial position, the electronic control unit 6 controls the motor 8 to apply a damping torque to the central shaft 3 in the opposite direction to the rotation of the pedal arm 2. Specifically, the electronic control unit 6 determines the current position of the pedal arm 2 by monitoring changes in the stroke signal or pressure signal; when the pedal arm 2 returns to a preset position close to the end of the initial position, the electronic control unit 6 controls the motor 8 to output torque in the opposite direction. This reverse torque is transmitted to the central shaft 3 after being reduced and increased in torque by the gear transmission mechanism 7, forming a damping torque in the opposite direction to the rotation of the pedal arm 2. The damping torque dampens the rotational movement of the pedal arm 2, causing the pedal arm 2 to gradually decelerate as it approaches the end of the initial position, suppressing the rebound impact when the pedal arm 2 returns to the end of the initial position, reducing abnormal noise caused by the rebound impact, and improving the overall NVH performance of the vehicle.

[0043] The magnitude of the damping torque can be adjusted by the electronic control unit 6 through the control of the output torque of the motor 8 to adapt to the different requirements of the pedal return end damping characteristics for different driving modes. During the active return process of the pedal arm 2, the electronic control unit 6 continuously monitors the position signal. When the pedal arm 2 enters the end damping range, the electronic control unit 6 switches the control target of the motor 8 from the active return drive torque to the end damping torque, realizing a smooth transition in the return process, so that the pedal arm 2 is under the active control of the electronic control unit 6 throughout the entire return stroke.

[0044] In some implementations, refer to Figure 3 A limit stop 9 is provided on the outer side of the pedal base 1, located at the end of the rotation stroke of the pedal arm 2 when it returns to the initial position. During the return process, when the pedal arm 2 returns to the initial position, the corresponding contact part on the pedal arm 2 contacts the limit stop 9, forming a mechanical limit on the rotation stroke of the pedal arm 2, preventing the pedal arm 2 from continuing to rotate beyond the initial position.

[0045] When the electronic control unit 6 is working normally, it controls the motor 8 to provide damping torque, allowing the pedal arm 2 to smoothly decelerate to its initial position. In the event of a malfunction in the electronic control unit 6, the limit stop block 9 mechanically limits the rotational travel of the pedal arm 2, preventing it from exceeding its initial position and ensuring braking safety. The limit stop block 9 is positioned corresponding to the initial position of the pedal arm 2. During installation, it must be positioned according to the initial angle of the vehicle's pedals to ensure accurate contact between the pedal arm 2 and the limit stop block 9 when it returns to its initial position.

[0046] In some embodiments, the contact surface of the limiting stop block 9 is provided with an elastic buffer layer, which is made of rubber or elastic polymer material and has a certain elastic deformation capacity. When the pedal arm 2 contacts the limiting stop block 9, the elastic buffer layer undergoes elastic deformation, absorbing the impact energy generated when the pedal arm 2 contacts the limiting stop block 9, buffering the contact impact force, reducing abnormal noise caused by the contact impact, and further improving the NVH performance at the end of the pedal return. The end damping control of the electronic control unit 6 ensures that the pedal arm 2 has significantly decelerated when approaching the end of the initial position, and the elastic buffer layer further absorbs the remaining impact energy. Together, they achieve flexible limiting at the end of the pedal arm 2's return.

[0047] The working process of this embodiment is as follows: During the pedal force adjustment phase, the pedal arm 2 is initially in its initial position, and the electronic control unit 6 is in standby mode. When the driver presses the pedal arm 2, the pedal arm 2 rotates around the central pivot 3 in the braking direction. The sensor of the drive-by-wire controller detects the change in pedal travel or pedal pressure, triggering a travel signal or pressure signal, which is then transmitted to the electronic control unit 6.

[0048] The electronic control unit 6 looks up the target pedal force corresponding to the current driving mode from a table based on the vehicle's driving mode signal, and determines the target output torque of the motor 8 accordingly. The electronic control unit 6 controls the motor 8 to rotate forward. The output shaft of the motor 8 drives the pinion gear to rotate, which meshes with the large gear. The large gear, through a spline connection, drives the central shaft 3 to rotate, applying a rotational torque to the pedal arm 2, ensuring that the rotational torque applied to the pedal arm 2 matches the target pedal force. The electronic control unit 6 continuously adjusts the actual output torque of the motor 8 through a current control closed loop, causing the pedal force to follow the target value, thus achieving continuous adjustment of the pedal force.

[0049] In Comfort mode, the electronic control unit 6 controls the motor 8 to output a first torque. After reduction and torque amplification via the gear transmission mechanism 7, the rotational torque applied to the central shaft 3 corresponds to the first target pedal force. The pedal arm 2 exhibits a lighter pedal force, allowing the driver to complete the braking operation with relatively little pressure, suitable for low-speed urban driving scenarios. In Standard mode, the electronic control unit 6 controls the motor 8 to output a second torque, corresponding to the second target pedal force. The pedal arm 2 exhibits the pedal force level under normal driving habits, suitable for daily driving scenarios. In Sport mode, the electronic control unit 6 controls the motor 8 to output a third torque, corresponding to the third target pedal force. The pedal arm 2 exhibits a heavier pedal force, requiring the driver to apply greater pressure to complete the braking operation, providing clear pedal force feedback, suitable for high-speed driving or scenarios requiring a strong driving control feel.

[0050] Since the switching of target pedal force in the three modes is achieved by adjusting the target output torque of motor 8 through electronic control unit 6, no hardware replacement is required. The entire switching process is transparent to the driver and responds quickly.

[0051] During the active pedal return phase, after the driver releases pedal arm 2, the electronic control unit 6 detects a decrease in the stroke or pressure signal, determines that the driver has released the pedal, and then controls motor 8 to reverse. When motor 8 reverses, the output shaft drives the pinion to rotate in the opposite direction. The pinion meshes with the large gear, and the large gear drives the central shaft 3 to rotate towards the initial position via a spline engagement, actively driving pedal arm 2 to rotate towards the initial position. Since the return process is actively driven by motor 8, the electronic control unit 6 can dynamically adjust the output torque of motor 8 in reverse according to the driving mode or preset parameters, thereby controlling the return rate of pedal arm 2.

[0052] In driving modes requiring a faster return response, the electronic control unit 6 increases the reverse output torque of the motor 8, accelerating the return rate of the pedal arm 2 and allowing it to quickly return to its initial position. In driving modes requiring a gentler return, the electronic control unit 6 reduces the reverse output torque of the motor 8, allowing the pedal arm 2 to return smoothly at a lower rate. Compared to the return method that relies on the passive restoring force of a spring, the return rate of the active return scheme can be adjusted as needed, overcoming the defect of the fixed and unadjustable return rate of existing schemes.

[0053] During the damping phase at the end of the pedal return, the electronic control unit 6 continuously monitors changes in the stroke or pressure signal during the active return of the pedal arm 2 to determine its current position. When the pedal arm 2 returns to a preset position close to the end of its initial position, the electronic control unit 6 controls the motor 8 to output a damping torque opposite to the rotation direction of the pedal arm 2. This damping torque is transmitted to the central rotating shaft 3 via the gear transmission mechanism 7, damping the rotational motion of the pedal arm 2 and causing the pedal arm 2 to gradually decelerate as it approaches the end of its initial position until it comes to a smooth stop at its initial position.

[0054] When the pedal arm 2 contacts the limit stop block 9, the pedal arm 2 has already decelerated significantly under the action of the damping torque, resulting in a smaller impact force upon contact. The elastic buffer layer further absorbs the remaining impact energy, thereby suppressing rebound impact and reducing abnormal noise caused by rebound impact. The entire end-of-return damping process is actively controlled by the electronic control unit 6, which, together with the mechanical limit of the limit stop block 9, constitutes a dual protection. When the electronic control unit 6 is working normally, it achieves flexible limiting; when the electronic control unit 6 malfunctions, the limit stop block 9 provides mechanical hard limiting to ensure braking safety.

[0055] Example 2: This embodiment provides a control method for an adjustable brake pedal device. Based on the adjustable brake pedal device in Embodiment 1, it uses an electronic control unit 6 as the core control unit and utilizes the stroke signal or pressure signal from the drive-by-wire controller as the control input. Through active control of the steering and output torque of the motor 8, it achieves full-process control of three stages: pedal force adjustment, active return, and end-damping. No additional sensors are required on the pedal side, reducing system cost while ensuring control reliability. The three stages of the control method are logically continuous and are automatically switched by the electronic control unit 6 based on real-time changes in the stroke or pressure signal, requiring no additional operation from the driver.

[0056] During the pedal force adjustment and control phase, the electronic control unit 6 collects the stroke signal or pressure signal output by the drive-by-wire controller and determines the target pedal force based on the vehicle driving mode or preset parameters.

[0057] Specifically, the electronic control unit 6 queries the preset parameter table based on the current vehicle driving mode signal to obtain the target pedal force corresponding to the current driving mode; the preset parameter table is written into the electronic control unit 6 through vehicle calibration, recording the mapping relationship between the target pedal force and the corresponding target output torque of the motor 8 in each driving mode such as comfort mode, standard mode, and sport mode.

[0058] The electronic control unit 6 determines the target output torque of the motor 8 based on the lookup table results, controls the motor 8 to rotate forward, and the output shaft of the motor 8 drives the pinion to rotate. The pinion meshes with the large gear, and the large gear drives the central shaft 3 to rotate via a spline connection, adjusting the rotational torque applied to the pedal arm 2 to match the pedal force with the target pedal force. The electronic control unit 6 continuously adjusts the actual output torque of the motor 8 through a current control closed loop, so that the pedal force follows the target value, achieving continuous adjustment of the pedal force.

[0059] When switching driving modes, the electronic control unit 6 immediately updates the lookup table results after receiving the new driving mode signal, and adjusts the actual output torque of the motor 8 to the target value corresponding to the new mode through the current control closed loop. The switching process is responsive.

[0060] During the active pedal return control phase, the electronic control unit 6 continuously monitors changes in the stroke or pressure signal. When a decrease in the stroke or pressure signal is detected, it determines that the driver has released the pedal and immediately switches the control target of the motor 8 from forward pedal force adjustment to reverse active return. The electronic control unit 6 controls the motor 8 to reverse, driving the central shaft 3 to rotate towards the initial position via the gear transmission mechanism 7, thus actively driving the pedal arm 2 to rotate towards the initial position. The electronic control unit 6 dynamically adjusts the output torque of the motor 8 in reverse according to the driving mode or preset parameters to control the return rate of the pedal arm 2.

[0061] In Comfort mode, the electronic control unit 6 controls the motor 8 to actively drive the pedal arm 2 back to its original position with a return torque corresponding to Comfort mode. The return process is smooth and gentle, suitable for the comfort requirements of pedal operation in urban low-speed driving scenarios. In Sport mode, the electronic control unit 6 controls the motor 8 to actively drive the pedal arm 2 back to its original position quickly with a higher return torque corresponding to Sport mode, meeting the need for rapid pedal response in Sport mode. In Standard mode, the return torque is between Comfort mode and Sport mode, corresponding to the return rate requirements in normal driving scenarios.

[0062] During the pedal return end damping control phase, the electronic control unit 6 continuously monitors changes in the stroke signal or pressure signal during the active return process to determine the current position of the pedal arm 2. When the pedal arm 2 returns to a preset position close to the end of the initial position, the electronic control unit 6 switches the control target of the motor 8 from the active return drive torque to the end damping torque. The motor 8 is controlled to apply a damping torque opposite to the rotation direction of the pedal arm 2 to the central rotating shaft 3 via the gear transmission mechanism 7, thereby damping the rotational motion of the pedal arm 2. This causes the pedal arm 2 to gradually decelerate as it approaches the end of the initial position until it stops smoothly at the initial position, suppressing the rebound impact of the pedal arm 2.

[0063] The magnitude of the end-damping torque can be adjusted according to the driving mode or preset parameters to adapt to the different requirements of the pedal return end-damping characteristics for different driving modes. When the pedal arm 2 contacts the limit stop block 9, since the pedal arm 2 has been significantly decelerated under the action of the damping torque, the impact force at contact is small. The elastic buffer layer on the contact surface of the limit stop block 9 further absorbs the remaining impact energy, thereby suppressing rebound impact and reducing the abnormal noise generated by rebound impact. The entire end-damping control process, together with the mechanical limit of the limit stop block 9, constitutes a dual protection. Flexible limit is achieved when the electronic control unit 6 is working normally, and mechanical hard limit is provided by the limit stop block 9 when the electronic control unit 6 fails, ensuring braking safety.

[0064] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A brake pedal device with adjustable pedal force, characterized in that, The device includes a pedal base and a pedal arm. The pedal arm is connected to the pedal base via a central rotating shaft, one end of which is connected to a drive assembly. The drive assembly includes a motor installed inside the housing and a gear transmission mechanism connected to the motor. The motor is connected to an electronic control unit, which is connected to a wired controller. The electronic control unit is used to collect stroke or pressure signals output by the wired controller, control the motor to rotate forward according to the collected signals to adjust the pedal force, and control the motor to rotate in reverse when the pedal returns to its original position to drive the pedal arm back to its original position.

2. The brake pedal device with adjustable pedal force according to claim 1, characterized in that, The gear transmission mechanism adopts a multi-stage planetary gear structure.

3. A brake pedal device with adjustable pedal force according to claim 1 or 2, characterized in that, The gear transmission mechanism includes a large gear and a small gear that mesh with each other. The large gear is mounted on a central rotating shaft, and the small gear is mounted on the output shaft of the motor.

4. The brake pedal device with adjustable pedal force according to claim 1, characterized in that, The housing is fixed to one side of the pedal base; The central rotating shaft is interference-fitted with the pedal base via a bearing.

5. A brake pedal device with adjustable pedal force according to claim 1, characterized in that, The electronic control unit determines the target pedal force based on the vehicle's driving mode, which includes at least comfort mode, standard mode, and sport mode.

6. A brake pedal device with adjustable pedal force according to claim 5, characterized in that, In comfort mode, the target pedal force is set to a first target pedal force, and the electronic control unit controls the motor to output a first torque; In standard mode, the target pedal force is set to a second target pedal force, and the electronic control unit controls the motor to output a second torque; in motion mode, the target pedal force is set to a third target pedal force, and the electronic control unit controls the motor to output a third torque. Wherein, the first target pedal force is less than the second target pedal force, the second target pedal force is less than the third target pedal force, the first torque is less than the second torque, and the second torque is less than the third torque.

7. A brake pedal device with adjustable pedal force according to claim 1, characterized in that, When the pedal arm returns to its initial position, the electronic control unit controls the motor to apply a damping torque to the central shaft in the opposite direction to the rotation of the pedal arm.

8. A brake pedal device with adjustable pedal force according to claim 1 or 7, characterized in that, The pedal base is provided with a limiting stop block on the outside, which is located at the end of the rotation stroke when the pedal arm returns to the initial position.

9. A brake pedal device with adjustable pedal force according to claim 8, characterized in that, The contact surface of the limiting stop block is provided with an elastic buffer layer.

10. A control method for a brake pedal device with adjustable pedal force according to any one of claims 1-9, characterized in that, include: The electronic control unit acquires the stroke signal or pressure signal output by the drive-by-wire controller; The electronic control unit determines the target pedal force based on the vehicle's driving mode or preset parameters, controls the motor to rotate forward, drives the central shaft to rotate via a gear transmission mechanism, and adjusts the rotational torque applied to the pedal arm to match the target pedal force. When the pedal returns to its original position, the electronic control unit controls the motor to reverse, which drives the central rotating shaft to rotate in the direction of the initial position via the gear transmission mechanism. This actively drives the pedal arm to rotate in the direction of the initial position, and dynamically adjusts the output torque of the motor to control the return rate according to the driving mode or preset parameters. When the pedal arm returns to its initial position, the electronic control unit controls the motor to apply a damping torque to the central shaft via a gear transmission mechanism, which is opposite to the direction of pedal arm rotation, to suppress the pedal arm's rebound impact.

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