A parking state detection control system and method

Abstract

The application relates to the technical field of parking systems and discloses a parking state detection control system and method, which comprises a wheel hub motor, a parking mechanism, a vehicle body pitch detection unit, a parking thrust detection unit and a main control module. The parking mechanism is arranged opposite to the wheel hub motor and has a parking state, a parking preparation release state and a parking complete release state. The parking mechanism comprises an electric push rod. The three states of the parking mechanism are switched through the extension and retraction of the electric push rod and the rotation of the wheel hub motor. The parking state detection control system and method can identify the parking state by self-checking the state of the electric push rod and the thrust condition, identify the parking environment through the vehicle body pitch detection unit, and then realize parking release through the cooperation of the wheel hub motor and the electric push rod, so that the hill start problem caused by insufficient braking force does not exist in the parking process, and the situation whether the parking system is unlocked can still be determined after the parking system is abnormal.

Description

Technical Field

[0001] This invention relates to the field of parking system technology, and in particular to a parking status detection and control system and method. Background Technology

[0002] Parking systems are primarily used to park vehicles on different roads and slopes and lock the wheels to prevent them from turning. Traditional parking mechanisms are divided into disc parking mechanisms and drum parking mechanisms. These use cable-operated or electronic EPB parking mechanisms to clamp the brake disc or brake drum, thereby parking the vehicle on different roads.

[0003] The parking control of a cable-operated parking mechanism is mainly controlled by a person. The parking success is determined by detecting the position of the parking handle. However, it cannot determine the clamping degree between the brake pads and the brake disc at the other end of the cable. Furthermore, the parking force varies from person to person. Generally, the parking pull force should be ≤400N. With a fixed transmission ratio of the parking mechanism, there are certain limitations in the design of the parking torque, which can easily lead to unstable parking and slippage on slopes.

[0004] The EPB parking mechanism generates parking thrust through a motor, which in turn drives the brake pads to produce parking force. This requires a relatively large transmission ratio and an interlocking worm gear mechanism to maintain parking even when power is off. This places certain demands on the power and torque of the brake motor. Over time, the transmission gears are prone to wear, reducing the reliability of the parking system. During fault detection, unsuccessful release of the parking brake or abnormal fluctuations in the torque transmitted by the transmission gears can cause abnormal motor torque, leading to a parking system fault report. Further manual inspection and analysis are needed to determine whether the fault lies with the motor, the worm gear mechanism, or the brake pad mechanism.

[0005] The parking torque of the above parking methods depends on the appropriate conversion of the force provided by the parking handle or motor to be converted into parking torque. The system can only detect abnormalities in the parking system, but cannot determine whether the parking system is unlocked. Summary of the Invention

[0006] In view of this, the present invention proposes a parking status detection and control system and method, which determines the parking status by self-testing the status and thrust of the electric push rod, identifies the parking environment by the vehicle body pitch detection unit, and then releases the parking by the coordinated action of the wheel hub motor and the electric push rod. During the parking process, there will be no slippage caused by insufficient braking force, and there will be no situation where it is impossible to determine whether the parking system has been unlocked after the parking system malfunctions.

[0007] The technical solution of this invention is implemented as follows:

[0008] On one hand, this invention provides a parking status detection and control system, including a hub motor, a parking mechanism, a vehicle pitch detection unit, a parking thrust detection unit, and a main control module, wherein,

[0009] The parking mechanism is arranged opposite to the hub motor. The parking mechanism has a parking state, a parking pre-release state, and a parking fully released state. The parking mechanism includes an electric push rod. The three states of the parking mechanism are switched by the extension and retraction of the electric push rod and the rotation of the hub motor.

[0010] The vehicle body pitch detection unit is installed on the vehicle to detect the parking slope;

[0011] The parking thrust detection unit is mounted on the electric push rod and is used to detect the magnitude of the electric push rod's thrust.

[0012] The main control module is electrically connected to the wheel hub motor, the vehicle body pitch detection unit, the parking thrust detection unit, and the electric push rod. By receiving the parking slope and thrust magnitude detected by the vehicle body pitch detection unit and the parking thrust detection unit, it determines the current state of the parking mechanism and controls the electric push rod and the wheel hub motor to switch states as needed.

[0013] In the parking state, the parking mechanism locks the rotor of the hub motor relative to the stator.

[0014] When the parking is ready to be released, the parking mechanism restricts the rotor and stator of the hub motor to only rotate relative to each other in one direction.

[0015] When the parking brake is fully released, the hub motor can move freely.

[0016] Based on the above technical solutions, preferably, the parking mechanism further includes a rotating shaft and a top block, wherein,

[0017] The shaft is fixed to the rotor part of the hub motor;

[0018] There are two top blocks, which are arranged opposite each other on different sides of the rotating shaft. The rotating shaft selectively abuts against one of the two top blocks, so that the rotating shaft cannot rotate toward the abutting side.

[0019] The electric push rod is fixed relative to the stator of the hub motor, and its output end is connected to two top blocks. The electric push rod is used to push the top blocks to contact or move away from the rotating shaft.

[0020] More preferably, in the parking state, both top blocks are in contact with the rotating shaft, thereby locking the rotor of the hub motor by restricting the rotating shaft from rotating to both sides;

[0021] When the parking is ready to be released, one of the two top blocks abuts against the rotating shaft, and the other top block moves away from the rotating shaft. The top block abutting against the rotating shaft restricts the rotation of the rotating shaft from rotating to the abutting side.

[0022] When the parking brake is fully released, both top blocks leave the pivot.

[0023] More preferably, in the parking state, the output end of the electric push rod pushes one of the two top blocks away from the rotating shaft to switch to the parking pre-release state;

[0024] When the parking brake is in the pre-release state, the rotor of the hub motor drives the rotating shaft to rotate away from the side that abuts against the top block, switching to the fully released parking brake state;

[0025] When the parking position is fully released, the output end of the electric push rod pushes the two top blocks to contact the rotating shaft, switching to the parking position.

[0026] More preferably, the parking mechanism further includes a plurality of protrusions, each of which is fixed on the rotating shaft, and one of the two top blocks selectively abuts against the protrusion, preventing the rotating shaft from rotating toward the abutting side of the top block.

[0027] Based on the above technical solutions, preferably, the parking mechanism further includes a flexible connection component, which is fixed to the output end of the electric push rod and flexibly connected to the two top blocks, for flexibly transmitting power between the electric push rod and the two top blocks.

[0028] More preferably, the flexible connection assembly includes a support and two elastic members, wherein,

[0029] The support is fixed to the output end of the electric actuator;

[0030] One end of each of the two elastic elements is mounted on one of the two top blocks, and the other end is hinged to the support.

[0031] On the other hand, the present invention provides a parking status detection and control method, which is based on the above-mentioned detection and control system and includes the following steps:

[0032] S1. Collect vehicle parking environment information, including parking slope;

[0033] S2. Determine the status of the parking mechanism based on the stroke status of the electric push rod and the magnitude of the output thrust;

[0034] S3. Input the required switching status of the parking mechanism into the main control module;

[0035] S4. Based on the vehicle parking environment information and the status of the parking mechanism, the main control module controls at least one of the wheel hub motor and electric push rod to perform an action, so that the current status of the parking mechanism is switched to the input status.

[0036] Based on the above technical solution, preferably, step S2 further includes setting a thrust threshold. When the electric push rod has the maximum stroke and the detected thrust is less than the thrust threshold, the parking mechanism is in a fully released parking state. When the electric push rod has the maximum stroke and the thrust is greater than the thrust threshold, the parking mechanism is in a parking pre-release state. When the electric push rod is in a minimum stroke state and the thrust is less than the thrust threshold, the parking mechanism is in a parking state.

[0037] Based on the above technical solutions, preferably, in step S4, when the parking pre-release state is switched to the parking fully released state, the switch is completed by the wheel hub motor, and the rotation direction of the wheel hub motor is determined by the parking slope.

[0038] The parking status detection and control system and method of the present invention have the following advantages over the prior art:

[0039] (1) By setting up a parking mechanism and switching between three states of the parking mechanism through the cooperation of electric push rod and wheel hub motor, the current parking state is obtained by the detection signal of the vehicle body pitch detection unit and the parking thrust detection unit. The parking state is judged by the self-test identification of the electric push rod state and the thrust situation. The parking environment is identified by the vehicle body pitch detection unit. Then, the parking is released through the cooperation of wheel hub motor and electric push rod. This ensures that there will be no slippage caused by insufficient braking force during parking. Even if the parking system is abnormal, it is still possible to determine whether the parking system is unlocked, thus improving parking safety.

[0040] (2) Displacement is determined by the maximum and minimum stroke of the push rod motor itself. Combined with the detection of the thrust value at the output end of the electric push rod by the parking thrust detection unit, the parking and unlocking states can be determined, thereby reducing the number of sensors and reducing system cost.

[0041] (3) The existing EPB parking mechanism generates parking thrust through the motor, which drives the brake pads to generate parking force. It requires a large transmission ratio. In contrast, this solution uses a hub motor to drive the auxiliary unlocking parking, which results in a smaller unlocking current, lower power consumption, and significantly reduced energy loss. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the parking status detection and control system of the present invention;

[0044] Figure 2 This is a schematic diagram showing the connection between the parking mechanism and the hub motor in the parking status detection and control system of the present invention;

[0045] Figure 3 This is an exploded view of the parking mechanism of the parking status detection and control system of the present invention;

[0046] Figure 4 This is a schematic diagram of the parking status of the parking mechanism of the parking status detection and control system of the present invention;

[0047] Figure 5 This is a schematic diagram of the parking pre-release state of the parking mechanism of the parking status detection and control system of the present invention.

[0048] Figure 6 This is a schematic diagram of the parking mechanism of the parking status detection and control system of the present invention in the fully released parking state.

[0049] Figure 7 This is a schematic diagram illustrating the steps of the parking status detection and control method of the present invention. Detailed Implementation

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0051] like Figure 1-6 As shown, the parking status detection and control system of the present invention includes a hub motor 1, a parking mechanism 2, a vehicle body pitch detection unit 3, a parking thrust detection unit 4, and a main control module 5.

[0052] The hub motor 1 is a major drive component in new energy vehicles, and its rotor is fixed to the vehicle's wheel hub.

[0053] The parking mechanism 2 is fixed relative to the stator of the hub motor 1. The parking mechanism 2 has a parking state, a parking pre-release state, and a parking fully released state. The parking mechanism 2 includes an electric push rod 23. The three states of the parking mechanism 2 are switched by the extension and retraction of the electric push rod 23 and the rotation of the hub motor 1.

[0054] The parking mechanism 2 specifically includes a base, a rotating shaft 21, a top block 22, and an electric push rod 23. The base is fixed to the stator of the hub motor 1, and the rotating shaft 21 is fixed to the rotor of the hub motor 1, with one end extending into the base. There are two top blocks 22, both hinged in the base and located on different sides of the rotating shaft 21. The top blocks 22 are mirror images of each other. The rotating shaft 21 selectively abuts against one of the two top blocks 22, preventing the rotating shaft 21 from rotating toward the abutting side. The electric push rod 23 is relatively fixed to the stator of the hub motor 1, and its output end is connected to the two top blocks 22. The electric push rod 23 is used to push the top blocks 22 to contact or move away from the rotating shaft 21. The parking mechanism 2 locks the wheel rotation by locking the rotating shaft 21, which is fixed to the rotor of the hub motor 1, thus achieving the parking action. The top blocks 22 prevent the rotating shaft 21 from rotating toward the contact side by abutting it, which is fundamentally different from the locking by clamping in the prior art.

[0055] To achieve the function of locking the rotating shaft 21 with the top block 22, the parking mechanism 2 also includes several protrusions 24, each of which is fixed on the rotating shaft 21. One of the two top blocks 22 selectively abuts against the protrusion 24, preventing the rotating shaft 21 from rotating toward the abutting side of the top block 22. In other words, the protrusion 24 restricts the rotating shaft 21 from rotating with the rotor of the hub motor 1 by cooperating with the top block 22. When the top block 22 is in contact with the rotating shaft 21 but does not abut against the protrusion 24, the top block 22 cannot prevent the rotating shaft 21 from rotating. Similarly, when the rotating shaft 21 rotates to the point where the protrusion 24 abuts against the top block 22, the rotating shaft 21 will no longer be able to rotate.

[0056] In addition, in this embodiment, the electric push rod 23 has three stroke states: maximum stroke, minimum stroke, and intermediate stroke. When the electric push rod 23 is at its minimum stroke, it pulls the two top blocks 22 to contact the rotating shaft 21, preventing its rotation, which is the parking state. The maximum stroke of the electric push rod 23 is the parking pre-release state or the parking fully release state. The distinction between these two states is determined by the force on the output end of the electric push rod 23.

[0057] The vehicle body pitch detection unit 3 is installed on the vehicle to detect the parking slope. The vehicle body pitch detection unit 3 can be a pitch sensor, also known as a slope sensor. The vehicle body pitch detection unit 3 is fixed to the vehicle body. The vehicle body pitch detection unit 3 detects the vehicle pitch state and angle. When the vehicle is facing uphill, the detection angle is positive, and the vehicle is judged to be parking in an uphill environment. Conversely, when the vehicle is facing downhill, the detection angle is negative, and the vehicle is judged to be parking in a downhill environment.

[0058] The parking thrust detection unit 4 is installed on the electric push rod 23 to detect the magnitude of the thrust of the electric push rod 23. The parking thrust detection unit 4 can use strain gauges for force detection. The electric push rod 23 is subjected to force and generates strain, which is read by the strain gauges and converted into the thrust value of the electric push rod 23. By reading the force condition of the electric push rod 23, it can be determined whether the electric push rod 23 is in the parking pre-release state or the parking fully released state when it is at its maximum stroke. Thus, the detection and determination of the three states of the parking mechanism 2 are completed, and the three states of the parking mechanism 2 also correspond to the vehicle state.

[0059] The main control module 5 is electrically connected to the hub motor 1, the vehicle pitch detection unit 3, the parking thrust detection unit 4, and the electric push rod 23. By receiving the parking slope and thrust magnitude detected by the vehicle pitch detection unit 3 and the parking thrust detection unit 4, it determines the current state of the parking mechanism 2 and controls the electric push rod 23 and the hub motor 1 to operate according to the required state switching. The vehicle pitch detection unit 3 and the parking thrust detection unit 4 convert the detected information into electrical signals and output them to the main control module 5. The main control module 5 then determines the current parking state. In this embodiment, the vehicle host can be directly used as the main control module 5.

[0060] When the vehicle is parked, the parking mechanism 2 locks the rotor and stator of the hub motor 1 relative to each other. Specifically, both top blocks 22 are in contact with the rotating shaft 21. By restricting the rotation of the rotating shaft 21 to both sides, the rotor of the hub motor 1 is locked. That is, the electric push rod 23 pushes the two top blocks 22 to rotate in the base, so that the ends of the two top blocks 22 that are close to each other are in contact with the rotating shaft 21. If the vehicle is parked on a slope, one of the top blocks 22 will rotate first, and the rotating shaft 21 will rotate toward that top block 22 to prevent the vehicle from rolling downhill when parking on a slope.

[0061] When the parking mechanism is ready to be released, the parking mechanism 2 restricts the rotor and stator of the hub motor 1 to rotate in only one direction relative to each other. One of the two top blocks 22 abuts against the shaft 21, and the other top block 22 moves away from the shaft 21. The top block 22 abutting against the shaft 21 restricts the shaft 21 from rotating towards the abutting side. Specifically, on a slope, since one of the two top blocks 22 abuts against the shaft 21, the electric push rod 23 cannot push the top block 22 abutting against the shaft 21 when pushing the top block 22 away from the shaft 21. It can only push the top block 22 that is not abutting. When parking on a slope, the component of the vehicle's gravity moves down the slope. Therefore, the top block 22 that abuts against the slope is located on the side that prevents the hub motor 1 from sliding down the slope. At this time, the rotor of the hub motor 1 can only rotate in the uphill direction.

[0062] When the parking brake is fully released, the hub motor 1 moves freely. At this time, both top blocks 22 are away from the shaft 21. In this state, the electric push rod 23 has its maximum stroke, and both top blocks 22 are away from the shaft 21. After the shaft 21 is no longer restricted by the top blocks 22, it can rotate freely.

[0063] Correspondingly, in the parking state, the output end of the electric push rod 23 pushes one of the two top blocks 22 away from the rotating shaft 21, switching to the parking pre-release state. It should be noted that when parking on a flat road, there may be a situation where the top block 22 contacts the rotating shaft 21 but does not abut against the protrusion 24. When neither of the two top blocks 22 abuts against the protrusion 24, the parking state can be directly pushed into the parking fully released state by the electric push rod 23. However, most outdoor roads have a certain slope. Therefore, before the parking state changes to the parking fully released state, it needs to first switch to the parking pre-release state, that is, a single top block 22 abuts against the protrusion 24, so that it cannot be pushed up by the electric push rod 23.

[0064] Correspondingly, in the parking pre-release state, the rotor of the hub motor 1 drives the rotating shaft 21 to rotate away from the side abutting against the top block 22, switching to the fully released parking state. It should be noted that in this state, since the electric push rod 23 is at its maximum stroke and a single top block 22 rotates away from the rotating shaft 21, the electric push rod 23 can be directly retracted to its minimum stroke to allow the other top block 22 to re-contact the rotating shaft 21, thus switching to the parking state. However, when switching to the fully released parking state, the electric push rod 23 is already in position, and only one top block 22 cannot be reset due to the resistance of the protrusion 24. At this time, the hub motor 1 drives the rotating shaft 21 to rotate at a small angle, causing the top block 22 to move away from the protrusion 24, thus switching from the parking pre-release state to the fully released parking state.

[0065] When the parking position is fully released, the output end of the electric push rod 23 pushes the two top blocks 22 to contact the rotating shaft 21, switching to the parking position. After the two top blocks 22 contact the rotating shaft 21, there is a gap between the two top blocks 22 for the protrusion 24 to engage. After the protrusion 24 engages in the gap, the two top blocks 22 can prevent the protrusion 24 from rotating in the direction of the two top blocks 22, so that the rotating shaft 21 cannot rotate forward or backward, thus locking the rotating shaft 21 with the rotor of the hub motor 1.

[0066] In this embodiment, in order to achieve synchronous flexible transmission between the output end of the electric push rod 23 and the two top blocks 22, a flexible connecting component 25 is also provided. The flexible connecting component 25 is fixed to the output end of the electric push rod 23 and is connected to the two top blocks 22 in a transmission manner. The flexible connecting component 25 applies a pushing and pulling force to the top blocks 22 through elastic deformation, so that even after the top blocks 22 are locked with the protrusions 24, they can still deform without causing the top blocks 22 to reset. Similarly, the flexible connecting component 25 can apply a force to the top blocks 22 to move away from the rotating shaft 21, so that it has a tendency to move away from the rotating shaft 21. When the top blocks 22 move away from the protrusions 24, they can move away from the rotating shaft 21 under this tendency, thereby releasing the parking brake.

[0067] The flexible connection assembly 25 includes two elastic elements 252. One end of each elastic element 252 is disposed on the output end of the electric push rod 23, and the other end is disposed on the two top blocks 22 respectively. Through the elastic deformation of the elastic elements 252, a flexible connection is achieved between the output end of the electric push rod 23 and the top blocks 22. In this embodiment, the elastic element 252 is preferably a spring. When the output end of the electric push rod 23 is pushed upward, the elastic elements 252 apply a tendency to move away from the rotating shaft 21 on the two top blocks 22. If there is no obstruction on the top block 22, it will drive the top block 22 to move upward away from the rotating shaft 21. If a single top block 22 is obstructed, the top block 22 will remain in contact with the protrusion 24, but the movement tendency applied to the top block 22 will remain unchanged until the protrusion 24 rotates away from the top block 22. Under this tendency, the top block 22 will rotate away from the rotating shaft 21, thus releasing the parking brake.

[0068] To enable the elastic element 252 to adapt to the relative rotation between the top block 22 and the output end of the electric push rod 23, the flexible connection assembly 25 further includes two supports 251. The connecting seat 52 is fixed on the output end of the electric push rod 23, and the two supports 251 are respectively hinged to the two ends of the connecting seat 52 and respectively fixed to the two elastic elements 252. When the top block 22 and the output end of the electric push rod 23 have relative displacement, the offset angle is large. The rotation of the supports 251 is used to compensate for this angle, thereby reducing the deformation of the elastic element 252 in directions other than the length direction and improving the expansion and contraction stability of the elastic element 252.

[0069] In this embodiment, when the top block 22 is not completely separated from the rotating shaft 21, the protrusion 24 may come into contact with the side of the top block 22 during rotation. Therefore, an arc-shaped groove is provided on the side of the top block 22 near the rotating shaft 21, so that the protrusion 24 can avoid the top block 22 through the arc-shaped groove, which greatly reduces the probability of contact and avoids mechanical collision and wear.

[0070] In addition, during the parking process, both top blocks 22 are in contact with the rotating shaft 21, but the protrusion 24 is not between the two top blocks 22. The rotatable protrusion 24 lifts one side of the top block 22 through the arc groove, so that the protrusion 24 rotates between the two top blocks 22 to achieve parking. Throughout the process, although the rotor of the hub motor 1 still has a certain angle of rotation after completing the parking action at different parking times before locking, due to the transmission ratio of about 8 to 12 between the rotating shaft 2 and the wheel, the rotation of the wheel during the actual parking process is extremely small, with a maximum of about 2°, which does not affect the actual parking effect.

[0071] In other words, when the vehicle needs to be parked, the electric push rod 23 retracts, and the parking top block 22 switches to the interlocked state, i.e., the parking state of the parking mechanism 2. At this time, the electric push rod 23 is detected to be at its minimum stroke and the thrust is small. When the vehicle needs to be released from parking, the electric push rod 23 begins to extend. Although it reaches its maximum stroke, the force of the push rod is insufficient to unlock the parking top block 22. The electric push rod 23 is in a high current and high thrust state. At the same time, the hub motor 1, based on the pitch angle data from the vehicle body pitch detection unit 3, will release the interlock of the parking top block 22 by rotating forward if a positive pitch angle is detected, and by rotating in reverse if a negative pitch angle is detected. At this time, the electric push rod 23 is detected to be in a low current and low thrust state, the parking release is completed, and the vehicle enters the driving state. When the electric push rod 23 is still in a high current and high thrust state, the hub motor 1 will continue to rotate forward or in reverse until the parking is successfully released.

[0072] like Figure 1-7 As shown, the parking status detection and control method of the present invention is implemented based on the above-mentioned detection and control system, and includes steps S1-S4.

[0073] Step S1: Collect vehicle parking environment information, including parking slope.

[0074] The collected parking slope, i.e. the pitch angle between the vehicle body and the horizontal plane, is detected by the vehicle body pitch detection unit 3.

[0075] Step S2: Determine the state of the parking mechanism 2 based on the stroke state of the electric push rod 23 and the magnitude of the output thrust.

[0076] In this step, a thrust threshold needs to be set. When the electric push rod 23 has the maximum stroke and the detected thrust is less than the thrust threshold, the parking mechanism 2 is in the fully released parking state. When the electric push rod 23 has the maximum stroke and the thrust is greater than the thrust threshold, the parking mechanism 2 is in the parking pre-release state. When the electric push rod 23 is in the minimum stroke state and the thrust is less than the thrust threshold, the parking mechanism 2 is in the parking state.

[0077] This step determines the status of the vehicle parking mechanism 2 and provides feedback to the main control module 5.

[0078] In addition, the stroke state of the electric push rod 23 in this step is the output signal of the electric push rod 23 itself, and the thrust magnitude information is collected by the parking thrust detection unit 4 installed on the electric push rod 23.

[0079] Step S3: Input the required switching status of the parking mechanism 2 into the main control module 5.

[0080] The states that need to be switched in this step include the parking state of the parking mechanism 2, the parking pre-release state, and the parking fully released state. It should be noted that the parking pre-release state is an intermediate state that can be used for vehicle starting. However, in some schemes, the parking pre-release state may not be set for the driver to choose, in order to reduce driving actions.

[0081] Step S4: The main control module 5 controls at least one of the wheel hub motor 1 and the electric push rod 23 to perform an action based on the vehicle parking environment information and the status of the parking mechanism 2, so that the current status of the parking mechanism 2 is switched to the input status.

[0082] In this step, when the parking pre-release state is switched to the parking fully released state, the hub motor 1 completes the switch. The rotation direction of the hub motor 1 is determined by the parking slope. When the vehicle body is at a positive angle to the horizontal plane, the hub motor 1 can switch to the parking fully released state by rotating forward. Conversely, when the vehicle body is at a negative angle to the horizontal plane, the hub motor 1 can switch to the parking fully released state by rotating in reverse. It should be noted that the forward and reverse rotation here are not forward and reverse rotation in the actual sense, but are relative to the vehicle's driving direction. Forward rotation means the vehicle is moving forward, and reverse rotation means the vehicle is moving backward.

[0083] In a specific embodiment, taking the electric push rod 23 with a working current of 1A and a thrust value of 20N under small thrust and a working current of 1.5A and a thrust value of 30N under large load thrust as an example, and the vehicle body pitch sensor monitoring range of -45° to 45°.

[0084] When the vehicle is stationary and the electric push rod 23 is not working, the detected thrust value is 20N. At this time, by reading the stroke of the electric push rod 23, if the electric push rod 23 is at its maximum stroke, it is determined that the parking is released and the wheel hub motor 1 can be powered normally to enter the driving state; if the electric push rod 23 is at its minimum stroke, it is determined that the parking is released and the wheel hub motor 1 cannot be powered. The vehicle can only be driven normally after the parking is released.

[0085] When the vehicle needs to release the parking brake, the electric push rod 23 extends. At this time, the current of the electric push rod 23 gradually increases from 1A to 1.5A, and the thrust value gradually increases from 20N to 30N. The detection result shows that the electric push rod 23 is in a large stroke and high thrust state, and the parking system is unlocking. At this moment, by reading the data from the vehicle body pitch detection unit 3, taking an angle of -5° as an example, it is determined that the vehicle is parked on a downhill section. At this time, the wheel hub motor 1 is controlled to reverse, causing the wheels to move backward by no more than 0.1°, thus releasing the interlock mechanism of the parking top block 22. The thrust of the electric push rod 23 changes from 30N to 20N, indicating that the parking brake release is complete and the vehicle can drive normally. Taking an angle of 5° detected by the vehicle body pitch detection unit 3 as an example, it is determined that the vehicle is parked on an uphill section. At this time, the wheel hub motor 1 is controlled to rotate forward, causing the wheels to move backward. If the vehicle moves forward by no more than 0.1°, the interlock mechanism of the parking roof block 22 will be released, and the thrust of the electric push rod 23 will change from 30N to 20N. This indicates that the parking release is complete and the vehicle can be driven normally. Taking the vehicle body pitch detection unit 3 detecting an angle of 0° as an example, if the vehicle is parked on a level road, the hub motor 1 will rotate forward and then reverse to drive the wheels forward and backward by no more than 0.1°, which will release the interlock mechanism of the parking roof block 22. The thrust of the electric push rod 23 will change from 30N to 20N, indicating that the parking release is complete and the vehicle can be driven normally. Throughout the control process, the change in the force of the electric push rod 23 is generated by the compression and energy storage of the spring on the parking roof block 22. When the stored energy is released, it is converted into the movement displacement of the parking roof block 22, which can then be used to determine the interlock and unlock status of the parking roof block 22.

[0086] In addition, in this embodiment, the effective contact length between the protrusion 24 and the top block 22 is 10mm, and the corresponding stroke of the electric push rod 23 is 14mm, so as to ensure that after unlocking, the height difference of the parking top block 22 rotation is greater than 10mm, thus avoiding the state of unsuccessful unlocking.

[0087] Taking a 40mm parking arm with a 40Cr material shaft 21 and top block 22 as an example, the parking torque under different contact lengths and widths is shown in the table below:

[0088]

[0089] The contact length refers to the length of contact between the rotating shaft 21 and the parking top block 22; the contact width refers to the width of contact between the rotating shaft 21 and the parking top block 22; the contact area is the contact length × the contact width; the contact strength refers to the yield strength of the material, which is 540 N / mm² for 40Cr material; the parking lever arm is the distance from the geometric center of the contact area to the rotation center; the contact force is the maximum contact force that the contact surface can withstand; and the parking braking torque is the maximum torque generated when locked.

[0090] As shown in the table, with a contact width of 10mm, each 1mm increase in contact width provides 216 N·m of parking braking torque. This means that by increasing the contact area through replacing the pivot 21 and the top block 22, different parking braking torque requirements for different vehicle models can be met, achieving cost-effective serialization. Alternatively, by replacing the material with a higher-strength one, the overall size of the parking mechanism 2 can be reduced to meet parking braking torque requirements. Similarly, the parking arm can also be adjusted to adapt to different structural layout spaces.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A parking status detection and control system, characterized in that, It includes a hub motor (1), a parking mechanism (2), a vehicle pitch detection unit (3), a parking thrust detection unit (4), and a main control module (5), among which, The parking mechanism (2) is arranged opposite to the hub motor (1). The parking mechanism (2) has a parking state, a parking pre-release state and a parking fully released state. The parking mechanism (2) includes an electric push rod (23). The three states of the parking mechanism (2) are switched by the extension and retraction of the electric push rod (23) and the rotation of the hub motor (1). The parking mechanism (2) also includes a rotating shaft (21), a top block (22), several protrusions (24), and a flexible connecting assembly (25), wherein, The rotating shaft (21) is fixed to the rotor part of the hub motor (1); There are two top blocks (22), which are arranged opposite each other on different sides of the rotating shaft (21). The rotating shaft (21) selectively abuts against one of the two top blocks (22), so that the rotating shaft (21) cannot rotate toward the abutting side. The electric push rod (23) is fixed relative to the stator of the hub motor (1), and the output end is connected to two top blocks (22). The electric push rod (23) is used to push the top blocks (22) to contact or leave the rotating shaft (21). Each of the protrusions (24) is fixed on the rotating shaft (21), and one of the two top blocks (22) selectively abuts against the protrusion (24), preventing the rotating shaft (21) from rotating toward the abutting side of the top block (22); The flexible connection assembly (25) is fixed on the output end of the electric push rod (23) and flexibly connected to the two top blocks (22) for flexible transmission between the electric push rod (23) and the two top blocks (22); The vehicle body pitch detection unit (3) is installed on the vehicle to detect the parking slope; The parking thrust detection unit (4) is installed on the electric push rod (23) to detect the magnitude of the thrust of the electric push rod (23); The main control module (5) is electrically connected to the hub motor (1), the vehicle body pitch detection unit (3), the parking thrust detection unit (4) and the electric push rod (23). By receiving the parking slope and thrust magnitude detected by the vehicle body pitch detection unit (3) and the parking thrust detection unit (4), it determines the current state of the parking mechanism (2) and controls the electric push rod (23) and the hub motor (1) to move according to the required state switching. In the parking state, both top blocks (22) are in contact with the rotating shaft (21). By restricting the rotating shaft (21) from rotating to both sides, the parking mechanism (2) locks the rotor and stator of the hub motor (1) relative to each other. In the parking state, the output end of the electric push rod (23) pushes one of the two top blocks (22) away from the rotating shaft (21) to switch to the parking preparation release state. When the parking is ready to be released, one of the two top blocks (22) abuts against the rotating shaft (21), and the other top block (22) moves away from the rotating shaft (21). The top block (22) abutting against the rotating shaft (21) restricts the rotating shaft (21) from rotating towards the abutting side. The parking mechanism (2) restricts the rotor and stator of the hub motor (1) to rotate relative to each other in only one direction. When the parking is ready to be released, the rotor of the hub motor (1) drives the rotating shaft (21) to rotate away from the abutting side of the top block (22), switching to the parking is fully released state. When the parking brake is fully released, both top blocks (22) leave the rotating shaft (21), and the hub motor (1) moves freely. When the parking brake is fully released, the output end of the electric push rod (23) pushes the two top blocks (22) to contact the rotating shaft (21) and switches to the parking brake state.

2. The parking status detection and control system as described in claim 1, characterized in that, The flexible connection assembly (25) includes a support (251) and two elastic members (252), wherein, The support (251) is fixed to the output end of the electric push rod (23); One end of each of the two elastic elements (252) is set on the two top blocks (22), and the other end is hinged to the support (251).

3. A parking status detection and control method, characterized in that, The detection and control system based on any one of claims 1-2 includes the following steps: S1. Collect vehicle parking environment information, including parking slope; S2. Determine the state of the parking mechanism (2) based on the stroke state of the electric push rod (23) and the magnitude of the output thrust. S3. Input the required switching status of the parking mechanism (2) into the main control module (5); S4. The main control module (5) controls at least one of the wheel hub motor (1) and electric push rod (23) to perform an action based on the vehicle parking environment information and the status of the parking mechanism (2), so that the current status of the parking mechanism (2) is switched to the input status.

4. The parking status detection and control method as described in claim 3, characterized in that, In step S2, a thrust threshold is set. When the electric push rod (23) has the maximum stroke and the detected thrust is less than the thrust threshold, the parking mechanism (2) is in a fully released parking state. When the electric push rod (23) has the maximum stroke and the thrust is greater than the thrust threshold, the parking mechanism (2) is in a parking pre-release state. When the electric push rod (23) is in a minimum stroke state and the thrust is less than the thrust threshold, the parking mechanism (2) is in a parking state.

5. The parking status detection and control method as described in claim 3, characterized in that, In step S4, when the parking pre-release state is switched to the parking fully released state, the switch is completed by the action of the hub motor (1), and the rotation direction of the hub motor (1) is determined by the parking slope.

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