Control method of multiplex power driving and braking integrated electric wheel system

Abstract

The invention discloses a control method of a multiplex power drive and brake integrated electric wheel system. The control method comprises the steps of a structure scheme of the multiplex power drive and brake integrated electric wheel system, multi-mode function and application scene division, multi-mode switching control method design and switching rule making. According to the electric wheel system, the wheel unit, the knuckle, the hub motor, the planetary gear reducer, the electronic wedge-shaped brake and the electromagnetic clutch are integrated, the hub motor is a power multiplexing unit for driving and braking work, a conventional braking execution motor and a speed reducer thereof are omitted, sprung mass is greatly reduced, and meanwhile the braking efficiency is improved. The electric wheel system can be matched with an electromagnetic clutch, switching of five working modes including driving, pure electric braking, compound braking, reversing braking and parking braking is achieved through the control method, the electric wheel system has various functions of a driving and braking integrated system, and the electric wheel system has great significance in driving and braking integrated cooperative control research of distributed driving.

Description

Technical Field

[0001] The present invention relates to the field of integrated drive and braking control for distributed drive technology of electric vehicles, and particularly to a control method for a power-reuse integrated drive and braking electric wheel system. Background Art

[0002] The intelligent chassis roadmap for passenger electric vehicles released in 2022 stipulates that the intelligent chassis is developing towards actuator distribution and control integration, and the integrated drive and braking control in the lateral and longitudinal directions should be achieved by 2025. Therefore, the drive system configuration is evolving from centralized drive to distributed drive. With the accelerating industrialization of the drive system centered on in-wheel motors and the penetration rate of the composite line control braking technology using electric braking + mechanical friction braking exceeding half, the industry has gradually started to focus on the high-integration structure design and multi-mode control methods for the integrated drive and braking electric wheel system in distributed drive technology. Regarding the integrated drive and braking control method, the following requirements are mainly focused on: (1) How to reasonably design the control method to ensure that the integrated drive and braking electric wheel system has basic functions such as driving, braking, reversing, and parking; (2) How to reasonably divide the application scenarios of the functions of the integrated drive and braking electric wheel system and, through control, enable the functions of the integrated drive and braking electric wheel system to accurately match and cover the corresponding application scenarios; (3) For the integrated drive and braking electric wheel system with high-integration design and power-reuse characteristics, how to ensure that the working states of components within the electric wheel system do not conflict during the multi-mode switching process through the control method; (4) For the integrated drive and braking electric wheel system adopting the power-reuse scheme of the drive and braking system, how to reasonably design the control method to achieve a reasonable distribution of the magnitudes of the electric braking torque and the mechanical friction braking torque.

[0003] In summary, the current automotive industry is in urgent need of a control method for the integrated drive and braking electric wheel system. Summary of the Invention

[0004] According to the background of the times, this paper designs a control method for an integrated drive and braking electric wheel system adopting the power-reuse scheme of the drive and braking system.

[0005] The technical solution of the present invention is as follows: A control method for a power-reuse integrated drive and braking electric wheel system, characterized in that its content includes:

[0006] The structural scheme of the power-reuse integrated drive and braking electric wheel system;

[0007] The multi-mode function and application scenario division based on the power-reuse integrated drive and braking electric wheel system;

[0008] The design of the multi-mode switching control method based on the power-reuse integrated drive and braking electric wheel system;

[0009] Formulation of multi-mode switching rules based on a reusable integrated power drive and brake electric wheel system.

[0010] Preferably, the structural solution of the reusable integrated power drive and brake electric wheel system is characterized by including:

[0011] The reusable integrated power drive and brake electric wheel system is composed of a wheel unit (100), a steering knuckle (200), a hub motor (300), a planetary gear reducer (400), an electronic wedge brake (500), and an electromagnetic clutch (600);

[0012] The wheel unit (100), including a tire, a rim, a spoke, and a brake disc, is mainly used to support the vehicle load and transmit driving and braking torques, and provides space for the high-integration layout of each system inside;

[0013] The steering knuckle (200), which is an important part of the suspension, is connected to the upper and lower double wishbones through ball pins, and is mainly used to connect the reusable integrated power drive and brake electric wheel system to the vehicle suspension and transmit forces and torques. There is a through hole in the middle for installing the hub motor, and a thick boss and bolt holes are provided on the left for installing the electronic wedge brake;

[0014] The hub motor (300), using a low-speed inboard motor, is used to provide the execution torque for the driving and braking conditions of the reusable integrated power drive and brake electric wheel system, and at the same time serves as the only power source for driving and braking operations. There is a through shaft at the rear side of the housing, which is connected to the through hole in the middle of the steering knuckle (200) by interference fit and fixed by bolts. There are threaded holes on the front side of the housing for installing the electromagnetic clutch;

[0015] The planetary gear reducer (400), including components such as an input shaft, a sun gear, a planetary gear, a planetary carrier, a ring gear, a reducer housing, and angular contact ball bearings, has a spline connection between the input shaft and the hub motor (300) to transmit the torque output by the hub motor (300) and achieve speed reduction and torque increase. The planetary carrier is provided with a positioning pin for installing the wheel unit (100) and is fixed by a flange nut;

[0016] The electronic wedge brake (500) includes components such as an electronic wedge brake support seat, an electronic wedge brake upper cover, a driven wedge block, a driving wedge block, a friction lining, and an electronic wedge brake return rubber block, and is used to provide the braking torque in the braking condition of the integrated motor wheel system for combined power drive and braking. The driving wedge block is provided with a short shaft connected to the short shaft sleeve at the upper end of the ring gear of the planetary gear reducer (400). In the braking condition, the electronic wedge brake (500) can drive the driving wedge block to push the driven wedge block through the movement of the ring gear of the planetary gear reducer (400), and finally clamp the brake disc of the wheel unit (100) with the friction lining to achieve the braking function;

[0017] The electromagnetic clutch (600) includes components such as rollers, a clutch outer hub, a clutch inner hub, a coil winding, an electromagnetic clutch return rubber block, and a fixed locking pin. Lugs are provided on both sides of the clutch outer hub and are connected to the front side of the housing of the hub motor (300) by screws. The clutch inner hub is in transitional fit connection with the middle hollow shaft provided on the ring gear of the planetary gear reducer (400). By controlling the on and off of the current on the coil winding, the working state of the electromagnetic clutch (600) is determined to achieve the switching of multiple drive and braking modes. When the electromagnetic clutch (600) is in the locked state, it will clamp the ring gear of the planetary gear reducer (400) to keep it stationary. When the electromagnetic clutch (600) is in the active state, the ring gear of the planetary gear reducer (400) can rotate freely.

[0018] Preferably, the multi-mode functions and application scenario divisions of the integrated motor wheel system for combined power drive and braking are characterized by including:

[0019] The working modes of the integrated motor wheel system for combined power drive and braking are mainly divided into a driving mode, a pure electric braking mode, a compound braking mode, a reverse braking mode, and a parking braking mode;

[0020] The driving mode is divided into forward driving and reverse driving, which are respectively applied to the scenarios of the vehicle driving forward and reversing. In the following text, the "driving mode" and "driving", without special instructions, default to the forward driving behavior;

[0021] The pure electric braking mode means that the braking torque of the whole vehicle is completely provided by electric braking, and is mainly applied to the braking scenarios at medium and low vehicle speeds and the braking scenarios at high vehicle speeds but with small braking intensities;

[0022] The compound braking mode means that the braking torque of the whole vehicle is provided jointly by electric braking and mechanical friction braking, and is mainly applied to the braking scenarios at extremely low vehicle speeds and the braking scenarios at high vehicle speeds with large braking intensities. Due to considering the working characteristics of the motor and the limitation of the motor efficiency in this scenario, it leads to the fact that the single electric braking is not sufficient to meet the braking demand at this time. Therefore, it is necessary to additionally introduce mechanical friction braking on the basis of electric braking to meet the braking demand;

[0023] The reverse braking mode is mainly applied to the braking scenario of the vehicle during reverse driving. Since the vehicle speed is usually extremely low under the reverse braking condition, the in-wheel motor (300) operates in a low-efficiency range, resulting in a relatively low electric braking intensity alone and being unable to complete a fast and efficient reverse braking action. Therefore, mechanical friction braking is introduced and a compound braking method is adopted for braking;

[0024] The parking braking mode is divided into flat ground parking braking, uphill slope parking braking with the vehicle head facing up, and downhill slope parking braking with the vehicle head facing down, which are respectively applied to the braking scenarios of flat ground parking, uphill slope parking with the vehicle head facing up, and downhill slope parking with the vehicle head facing down.

[0025] Preferably, the design of the multi-mode switching control method for the integrated power drive and braking in-wheel system is characterized by including:

[0026] The design of the multi-mode switching control method for the integrated power drive and braking in-wheel system mainly includes the control method designs for the drive mode, pure electric braking mode, compound braking mode, reverse braking mode, and parking braking mode;

[0027] Define a rotation direction reference system. When the wheel unit (100) moves forward in the positive direction, the direction of its own rotation around the rotation axis is the positive rotation direction.

[0028] Preferably, the design of the drive mode control method for the integrated power drive and braking in-wheel system is characterized by including:

[0029] The drive mode control method, when operating under the forward drive condition, controls the in-wheel motor (300) to operate in the first quadrant, being in the state of positive rotational speed and positive torque. When operating under the reverse drive condition, it controls the in-wheel motor (300) to operate in the third quadrant. For both the forward drive and reverse drive conditions of the drive mode, it controls the electromagnetic clutch (600) to be in the locked state.

[0030] Preferably, the design of the pure electric braking mode control method for the integrated power drive and braking in-wheel system is characterized by including:

[0031] The pure electric braking mode control method controls the in-wheel motor (300) to operate in the fourth quadrant, being in the state of positive rotational speed and negative torque, and controls the electromagnetic clutch (600) to be in the locked state. At this time, the total vehicle braking torque is completely provided by electric braking, and the ratio of the output torque of the in-wheel motor (300) to the total braking torque is where k is the characteristic coefficient of the planetary gear reducer (400).

[0032] Preferably, the design of the composite braking mode control method for the integrated electric wheel system based on multiplexed power drive and braking is characterized by including:

[0033] The composite braking mode is divided into an efficiency type composite braking mode and an energy-saving type composite braking mode according to whether the ratio of the electric braking torque to the mechanical friction braking torque is adjustable, and can be set according to the user's own preference;

[0034] In the efficiency type composite braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a fixed ratio, and at this time, the proportion of the mechanical braking torque in the total braking torque reaches the maximum value, mainly pursuing the driving performance of the whole vehicle and experiencing the driving pleasure;

[0035] In the energy-saving type composite braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a variable ratio. On the premise of meeting the braking requirements, as much braking torque as possible is distributed to the electric braking, and energy-saving driving is realized through braking energy recovery to improve the economy of the whole vehicle;

[0036] The control method for the efficiency type composite braking mode controls the hub motor (300) to work in the fourth quadrant, in a positive rotational speed and negative torque state. The electromagnetic clutch (600) is controlled to be in an active state throughout the process. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to clamp the brake disc of the wheel unit (100) to apply mechanical friction braking. At this time, the braking torque of the whole vehicle is provided jointly by mechanical friction braking and electric braking, and the ratio of the two torque magnitudes is a fixed value λ is related to the internal parameters of the electronic wedge brake (500), such as the transmission ratio and mechanical efficiency, etc. The ratio of the output torque of the hub motor (300) to the total braking torque magnitude is The total braking torque output can be controlled by adjusting the torque output of the hub motor (300). When canceling braking, first control the operating point of the hub motor (300) to quickly switch to the first quadrant. At this time, the ring gear of the planetary gear reducer (400) rotates reversely, driving the active wedge block of the electronic wedge brake (500) back to the center position. This step is simply called "returning to position". At this time, the electronic wedge brake (500) will automatically separate from the brake disc of the wheel unit (100), and then quickly control the electromagnetic clutch (600) to lock;

[0037] Energy-saving composite braking mode control method, which controls the hub motor (300) to operate in the fourth quadrant, in a state of positive rotational speed and negative torque. Different from the efficiency-type composite braking mode, the electromagnetic clutch (600) is not in an active state throughout the process, but its state switching is controlled in real time according to the target ratio of the electric braking torque to the mechanical friction braking torque. Since in the composite braking mode, the proportion of mechanical friction braking in the total braking torque depends on the position of the active wedge of the electronic wedge brake (500), and thus depends on the angle turned by the ring gear of the planetary gear reducer (400), first control the electromagnetic clutch (600) to be in an active state, and the ring gear of the planetary gear reducer (400) starts to reverse. After it turns a certain angle, quickly control the electromagnetic clutch (600) to switch to the locked state, fixing the position of the ring gear of the planetary gear reducer (400) at this time, then the mechanical friction braking torque and the electric braking torque can be controlled to be in any proportion. The relationship is that the ratio of the output torque of the hub motor (300) to the total braking torque is The total braking torque output can be controlled by adjusting the torque output of the hub motor (300). When canceling the braking, first control the operating point of the hub motor (300) to quickly switch to the first quadrant, control the electromagnetic clutch (600) to be in an active state, so that the electronic wedge brake (500) completes the return, and then quickly control the electromagnetic clutch (600) to lock.

[0038] Preferably, the design of the reverse braking mode control method for the integrated power drive and braking electric wheel system based on multiplexing is characterized by including:

[0039] Reverse braking mode, which controls the hub motor (300) to operate in the second quadrant, in a state of negative rotational speed and positive torque. The electromagnetic clutch (600) is controlled to be in an active state throughout the process. At this time, the ring gear of the planetary gear reducer (400) reverses, driving the movement of the active wedge of the electronic wedge brake (500), and finally actuating the electronic wedge brake (500) to clamp the brake disc of the wheel unit (100), applying mechanical friction braking. At this time, the vehicle braking torque is provided by both mechanical friction braking and electric braking. When canceling the braking, first control the operating point of the hub motor (300) to quickly switch to the third quadrant. At this time, the ring gear of the planetary gear reducer (400) rotates forward, causing the electronic wedge brake (500) to complete the return, and then quickly control the electromagnetic clutch (600) to lock;

[0040] Preferably, the design of the parking braking mode control method for the integrated power drive and braking electric wheel system based on multiplexing is characterized by including:

[0041] Parking braking mode is divided into three types: flat ground parking braking, uphill parking braking with the front of the vehicle facing up, and downhill parking braking with the front of the vehicle facing down;

[0042] In the flat ground parking brake scenario, the electromagnetic clutch (600) is controlled to be in the active state, and at the same time, the in-wheel motor (300) is controlled to operate in the third quadrant, in a negative rotational speed and negative torque state. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short period of time. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to fully clamp the brake disc of the wheel unit (100). At this time, the electromagnetic clutch (600) is controlled to be in the locked state, completing the flat ground parking brake. When the vehicle starts and needs to cancel the parking brake mode, the electromagnetic clutch (600) is controlled to be in the active state, and the in-wheel motor (300) is controlled to operate in the first quadrant. Since the vehicle is still regarded as stationary in a short period of time, the ring gear of the planetary gear reducer (400) rotates forward, causing the electronic wedge brake (500) to return to its original position, and then the electromagnetic clutch (600) is controlled to be in the locked state. At this time, the vehicle has met the control conditions required for the driving mode and can be directly switched to the driving mode;

[0043] In the head-down slope parking brake scenario, at this time, the vehicle has a tendency to move forward, which can be analogized to the braking scenario at extremely low vehicle speeds in the compound braking mode. The electromagnetic clutch (600) is controlled to be in the active state, and at the same time, the in-wheel motor (300) is controlled to operate in the fourth quadrant, in a positive rotational speed and negative torque state. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to fully clamp the brake disc of the wheel unit (100). During this process, the vehicle may be accompanied by a slight forward shake. After the vehicle stops stably, the electromagnetic clutch (600) is controlled to be in the locked state, completing the head-down slope parking brake. When the vehicle starts and needs to cancel the parking brake mode, the electromagnetic clutch (600) is controlled to be in the active state, and the in-wheel motor (300) is controlled to operate in the first quadrant. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short period of time. At this time, the ring gear of the planetary gear reducer (400) rotates reversely, causing the electronic wedge brake (500) to return to its original position, and then the electromagnetic clutch (600) is controlled to be in the locked state. At this time, the vehicle has met the control conditions required for the driving mode and can be directly switched to the driving mode;

[0044] In the case of slope parking brake with the vehicle head facing upward, at this time, the vehicle has a tendency to move backward, which can be analogized to the braking scenario of the reverse braking mode. Control the electromagnetic clutch (600) to be in the active state, and at the same time control the in-wheel motor (300) to work in the second quadrant, with a negative rotational speed and a positive torque state. At this time, the ring gear of the planetary gear reducer (400) rotates in reverse, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to fully clamp the brake disc of the wheel unit (100). During this process, the vehicle may be accompanied by a slight backward shake. After the vehicle stops stably, control the electromagnetic clutch (600) to be in the locked state to complete the slope parking brake with the vehicle head facing upward. When the vehicle starts and needs to cancel the parking brake mode, control the electromagnetic clutch (600) to be in the active state, and control the in-wheel motor (300) to work in the third quadrant. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short time. At this time, the ring gear of the planetary gear reducer (400) rotates forward, causing the electronic wedge brake (500) to return to its original position. Then control the electromagnetic clutch (600) to be in the locked state, and then control the operating point of the in-wheel motor (300) to switch to the first quadrant, so that the vehicle can be switched to the driving mode;

[0045] Preferably, the formulation of the multi-mode switching rules of the integrated power drive and brake in-wheel system is characterized by including:

[0046] The multi-mode switching rules of the integrated power drive and brake in-wheel system are composed of three main bodies, namely the drive layer, the service braking layer, and the parking braking layer. Among them, the drive layer is composed of drive modes, the service braking layer is composed of pure electric braking mode, compound braking mode, and reverse braking mode, and the parking braking layer is composed of parking braking modes for three scenarios: flat ground parking brake, slope parking brake with the vehicle head facing upward, and slope parking brake with the vehicle head facing downward;

[0047] When the vehicle starts, the system enters the parking braking layer, that is, the vehicle is in the parking brake state. At this time, the driver decides whether to drive the vehicle or end using the vehicle. If the driver chooses to drive the vehicle, the system enters the drive layer, that is, the vehicle is in the driving state. During driving, the system can automatically or according to the driver's intention switch between the drive layer and the service braking layer to complete the driving task. When the vehicle decelerates to zero speed in the service braking state, the system can automatically or according to the driver's intention choose to drive again or stop. Here, it is mainly considered that there may be scenarios such as waiting for a traffic light or other short-term stops. If the driver chooses to drive again, the system returns to the drive layer, that is, the vehicle returns to the driving state. If the driver chooses to stop, the system enters the parking braking layer, that is, the vehicle is in the parking brake state;

[0048] In addition, whether it is the service brake layer or the parking brake layer, it is necessary to ensure that the electronic wedge brake (600) has completed the return operation before successfully switching to the drive layer.

[0049] The technical achievements of the present invention are as follows:

[0050] Based on the structural scheme of the integrated power drive and brake electric wheel system with multiplexing, the multi-mode functions and application scenarios are divided. According to the functional requirements of each working mode of the integrated power drive and brake electric wheel system with multiplexing, the multi-mode switching control method is designed and the multi-mode switching rules are formulated, forming a complete set of control scheme systems for the integrated power drive and brake electric wheel system with multiplexing. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is the design flow chart in the embodiment of the present invention;

[0052] Figure 2 is the axonometric view of the structural scheme of the integrated power drive and brake electric wheel system described in the present invention;

[0053] Figure 3 is the exploded axonometric view of the structural scheme of the integrated power drive and brake electric wheel system described in the present invention;

[0054] Figure 4 is the exploded top view of the structural scheme of the integrated power drive and brake electric wheel system described in the present invention;

[0055] Figure 5 is the axonometric view of the internal structure of the electronic wedge brake described in the present invention;

[0056] Figure 6 is the block diagram of the multi-mode switching rules based on the integrated power drive and brake electric wheel system described in the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0057] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0058] The present invention proposes a control method for an integrated power drive and brake electric wheel system with multiplexing, as Figure 1 shown, which mainly includes: the structural scheme of the integrated power drive and brake electric wheel system with multiplexing; the multi-mode functions and application scenarios division based on the integrated power drive and brake electric wheel system with multiplexing; the multi-mode switching control method design based on the integrated power drive and brake electric wheel system with multiplexing; the multi-mode switching rules formulation based on the integrated power drive and brake electric wheel system with multiplexing.

[0059] Among them, the structural scheme of the integrated power drive and brake electric wheel system with multiplexing is mainly asFigure 2 , 3 As shown in Figures 3 and 4, the integrated motorized drive and brake electric wheel system consists of a wheel unit (100), a steering knuckle (200), a hub motor (300), a planetary gear reducer (400), an electronic wedge brake (500), and an electromagnetic clutch (600).

[0060] Among them, the wheel unit (100) includes a tire, a rim, a spoke, and a brake disc, and is mainly used to support the vehicle load and transmit driving and braking torques, providing space for the high-integration layout of each system inside; among them, the steering knuckle (200) is an important part of the suspension, connected to the upper and lower double wishbones through ball pins, mainly used to connect the integrated motorized drive and brake electric wheel system to the vehicle suspension, transmitting forces and torques, and having a through hole in the middle for installing the hub motor, and a thick boss and bolt holes on the left for installing the electronic wedge brake; among them, the hub motor (300) uses a low-speed inboard motor, which is used to provide the executive torque for the driving and braking conditions of the integrated motorized drive and brake electric wheel system, and at the same time serves as the only power source for driving and braking work. There is a through shaft at the rear side of the housing, which is connected with the through hole in the middle of the steering knuckle (200) by interference fit and fixed by bolts. There are threaded holes on the front side of the housing for installing the electromagnetic clutch; among them, the planetary gear reducer (400) includes components such as an input shaft, a sun gear, a planetary gear, a planetary carrier, a ring gear, a reducer housing, and angular contact ball bearings. The input shaft is splined to the hub motor (300) to transmit the torque output by the hub motor (300) to achieve speed reduction and torque increase. The planetary carrier is provided with a positioning pin for installing the wheel unit (100) and fixed by a flange nut; among them, the electronic wedge brake (500) includes components such as an electronic wedge brake support seat, an electronic wedge brake upper cover, a driven wedge block, a driving wedge block, a friction lining, and an electronic wedge brake return rubber block. Its internal structure is as Figure 5As shown, it is used to provide the braking torque for the braking condition of the integrated motorized wheel system with multiplexed power drive and braking. The active wedge block is provided with a short shaft connected to the short shaft sleeve at the upper end of the ring gear of the planetary gear reducer (400). In the braking condition, the electronic wedge brake (500) can drive the active wedge block to push the driven wedge block through the movement of the ring gear of the planetary gear reducer (400), and finally make the friction lining clamp the brake disc of the wheel unit (100) to achieve the braking function. The electromagnetic clutch (600) includes components such as rollers, a clutch outer hub, a clutch inner hub, a coil winding, an electromagnetic clutch return rubber block, and a fixed locking pin. The two sides of the clutch outer hub are provided with lugs and are connected to the front side of the housing of the hub motor (300) by screws. The clutch inner hub is in transitional fit connection with the middle hollow shaft provided on the ring gear of the planetary gear reducer (400). By controlling the on-off of the current on the coil winding, the working state of the electromagnetic clutch (600) is determined to achieve the switching of multiple drive and braking modes. When the electromagnetic clutch (600) is in the locked state, it will clamp the ring gear of the planetary gear reducer (400) to keep it stationary. When the electromagnetic clutch (600) is in the active state, the ring gear of the planetary gear reducer (400) can rotate freely.

[0061] Among them, for the multi-mode function and application scenario division of the integrated motorized wheel system with multiplexed power drive and braking, it is characterized in that the working modes of the integrated motorized wheel system with multiplexed power drive and braking are mainly divided into a driving mode, a pure electric braking mode, a compound braking mode, a reverse braking mode, and a parking braking mode.

[0062] Among them, the driving mode is divided into forward driving and reverse driving, which are respectively applied to the scenarios of forward driving and reverse driving of the vehicle. In the following text, "driving mode" and "driving", without special instructions, are defaulted to forward driving behavior; among them, the pure electric braking mode means that the total vehicle braking torque is completely provided by electric braking, which is mainly applied to the braking scenarios of medium and low vehicle speeds and the braking scenarios of high vehicle speeds but with small braking intensities; among them, the composite braking mode means that the total vehicle braking torque is jointly provided by electric braking and mechanical friction braking, which is mainly applied to the braking scenarios of extremely low vehicle speeds and the braking scenarios of high vehicle speeds with large braking intensities. Due to considering the motor working characteristics and motor efficiency limitations in this scenario, it leads to that the single electric braking is not sufficient to meet the braking requirements at this time. Therefore, it is necessary to additionally introduce mechanical friction braking on the basis of electric braking to meet the braking requirements; among them, the reverse braking mode is mainly applied to the braking scenario of vehicle reverse driving. Since the vehicle speed is usually extremely low under the reverse braking condition and the in-wheel motor (300) works in a low-efficiency range, resulting in a low electric braking intensity and being unable to complete a fast and efficient reverse braking action, mechanical friction braking is introduced and the composite braking method is used for braking; among them, the parking braking mode is divided into flat ground parking braking, uphill parking braking with the front of the vehicle facing up and downhill parking braking with the front of the vehicle facing down, which are respectively applied to the braking scenarios of flat ground parking, uphill parking with the front of the vehicle facing up and downhill parking with the front of the vehicle facing down.

[0063] Among them, the design of the multi-mode switching control method based on the integrated power drive and braking in-wheel system mainly includes the control method design of the driving mode, pure electric braking mode, composite braking mode, reverse braking mode, and parking braking mode, and defines the rotation direction reference system. When the wheel unit (100) moves forward in the positive direction, its own rotation direction around the rotation axis is the positive rotation direction.

[0064] Among them, the driving mode control method, when working under the forward driving condition, controls the in-wheel motor (300) to work in the first quadrant, in a positive rotational speed and positive torque state, while when working under the reverse driving condition, controls the in-wheel motor (300) to work in the third quadrant. Whether it is the driving mode under the forward driving or reverse driving condition, the electromagnetic clutch (600) is controlled to be in the locked state.

[0065] Among them, the pure electric braking mode control method controls the in-wheel motor (300) to work in the fourth quadrant, in a positive rotational speed and negative torque state, and controls the electromagnetic clutch (600) to be in the locked state. At this time, the total vehicle braking torque is completely provided by electric braking, and the ratio of the output torque of the in-wheel motor (300) to the total braking torque is where k is the characteristic coefficient of the planetary gear reducer (400).

[0066] The composite braking mode is divided into an efficiency - type composite braking mode and an energy - saving type composite braking mode according to whether the ratio of the electric braking torque to the mechanical friction braking torque is adjustable, and can be set according to the user's own preference. In the efficiency - type composite braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a fixed ratio, and at this time, the proportion of the mechanical braking torque in the total braking torque reaches the maximum value, mainly pursuing the driving performance of the whole vehicle and experiencing the driving pleasure. In the energy - saving type composite braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a variable ratio. On the premise of meeting the braking requirements, as much braking torque as possible is distributed to the electric braking, and energy - saving driving is realized through braking energy recovery to improve the economy of the whole vehicle.

[0067] For the control method of the efficiency - type composite braking mode, the in - wheel motor (300) is controlled to work in the fourth quadrant, in a state of positive speed and negative torque. The electromagnetic clutch (600) is controlled to be in the active state throughout the process. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge - type brake (500) to move, and finally actuating the electronic wedge - type brake (500) to clamp the brake disc of the wheel unit (100) to apply mechanical friction braking. At this time, the braking torque of the whole vehicle is provided jointly by mechanical friction braking and electric braking, and the ratio of the magnitudes of the two torques is a fixed value. λ is related to the internal parameters of the electronic wedge - type brake (500), such as the transmission ratio and mechanical efficiency, etc. The ratio of the output torque of the in - wheel motor (300) to the magnitude of the total braking torque is The output of the total braking torque can be controlled by adjusting the torque output of the in - wheel motor (300). When canceling the braking, first control the operating point of the in - wheel motor (300) to quickly switch to the first quadrant. At this time, the ring gear of the planetary gear reducer (400) rotates in reverse, driving the active wedge block of the electronic wedge - type brake (500) back to the central position. This step is briefly called "returning to position". At this time, the electronic wedge - type brake (500) will automatically separate from the brake disc of the wheel unit (100), and then quickly control the electromagnetic clutch (600) to lock.

[0068] Among them, for the energy-saving composite braking mode control method, the hub motor (300) is controlled to operate in the fourth quadrant, in a state of positive rotational speed and negative torque. Different from the efficiency composite braking mode, the electromagnetic clutch (600) is not in an active state throughout the process, but its state switching is controlled in real time according to the target ratio of the electric braking torque to the mechanical friction braking torque. Since in the composite braking mode, the proportion of the mechanical friction braking in the total braking torque depends on the position of the active wedge block of the electronic wedge brake (500), and thus depends on the angle rotated by the ring gear of the planetary gear reducer (400), the electromagnetic clutch (600) is first controlled to be in an active state, and the ring gear of the planetary gear reducer (400) starts to reverse. After it rotates a certain angle, the electromagnetic clutch (600) is quickly controlled to switch to the locked state, fixing the position of the ring gear of the planetary gear reducer (400) at this time, then the mechanical friction braking torque and the electric braking torque can be controlled to be in any ratio. The relationship is that the ratio of the output torque of the hub motor (300) to the total braking torque is The total braking torque output can be controlled by adjusting the torque output of the hub motor (300). When canceling the braking, first control the operating point of the hub motor (300) to quickly switch to the first quadrant, control the electromagnetic clutch (600) to be in an active state, so that the electronic wedge brake (500) completes the return, and then quickly control the electromagnetic clutch (600) to lock.

[0069] Among them, for the reverse braking mode, the hub motor (300) is controlled to operate in the second quadrant, in a state of negative rotational speed and positive torque. The electromagnetic clutch (600) is controlled to be in an active state throughout the process. At this time, the ring gear of the planetary gear reducer (400) reverses, driving the movement of the active wedge block of the electronic wedge brake (500), and finally actuating the electronic wedge brake (500) to clamp the brake disc of the wheel unit (100), applying mechanical friction braking. At this time, the vehicle braking torque is provided by both mechanical friction braking and electric braking. When canceling the braking, first control the operating point of the hub motor (300) to quickly switch to the third quadrant. At this time, the ring gear of the planetary gear reducer (400) rotates forward, so that the electronic wedge brake (500) completes the return, and then quickly control the electromagnetic clutch (600) to lock.

[0070] Among them, the parking brake mode is divided into three types: flat ground parking brake, uphill slope parking brake with the vehicle head facing up, and downhill slope parking brake with the vehicle head facing down. In the flat ground parking brake scenario, the electromagnetic clutch (600) is controlled to be in an active state, and at the same time, the in-wheel motor (300) is controlled to operate in the third quadrant, in a negative speed and negative torque state. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short time. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to completely clamp the brake disc of the wheel unit (100). At this time, the electromagnetic clutch (600) is controlled to be in a locked state, completing the flat ground parking brake. When the vehicle starts and the parking brake mode needs to be cancelled, the electromagnetic clutch (600) is controlled to be in an active state, and the in-wheel motor (300) is controlled to operate in the first quadrant. Since the vehicle is still regarded as stationary in a short time, the ring gear of the planetary gear reducer (400) rotates forward, causing the electronic wedge brake (500) to return to its original position, and then the electromagnetic clutch (600) is controlled to be in a locked state. At this time, the vehicle has met the control conditions required for the driving mode and can be directly switched to the driving mode. In the downhill slope parking brake scenario, at this time, the vehicle has a tendency to move forward, which can be analogized to the braking scenario at extremely low vehicle speeds in the compound braking mode. The electromagnetic clutch (600) is controlled to be in an active state, and at the same time, the in-wheel motor (300) is controlled to operate in the fourth quadrant, in a positive speed and negative torque state. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to completely clamp the brake disc of the wheel unit (100). During this process, the vehicle may be accompanied by a slight forward shake. After the vehicle stops stably, the electromagnetic clutch (600) is controlled to be in a locked state, completing the downhill slope parking brake. When the vehicle starts and the parking brake mode needs to be cancelled, the electromagnetic clutch (600) is controlled to be in an active state, and the in-wheel motor (300) is controlled to operate in the first quadrant. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short time. At this time, the ring gear of the planetary gear reducer (400) rotates in the reverse direction, causing the electronic wedge brake (500) to return to its original position, and then the electromagnetic clutch (600) is controlled to be in a locked state. At this time, the vehicle has met the control conditions required for the driving mode and can be directly switched to the driving mode;In the case of slope parking brake with the vehicle head facing upward, at this time, the vehicle has a tendency to move backward, which can be analogized to the braking scenario of the reverse braking mode. Control the electromagnetic clutch (600) to be in the active state, and at the same time control the in-wheel motor (300) to work in the second quadrant, with a negative rotational speed and a positive torque state. At this time, the ring gear of the planetary gear reducer (400) rotates in reverse, driving the active wedge of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to completely clamp the brake disc of the wheel unit (100). During this process, the vehicle may be accompanied by a slight backward shake. After the vehicle stops stably, control the electromagnetic clutch (600) to be in the locked state to complete the slope parking brake with the vehicle head facing upward. When the vehicle starts and needs to cancel the parking brake mode, control the electromagnetic clutch (600) to be in the active state, and control the in-wheel motor (300) to work in the third quadrant. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short time. At this time, the ring gear of the planetary gear reducer (400) rotates forward, causing the electronic wedge brake (500) to return to its original position. Then control the electromagnetic clutch (600) to be in the locked state, and then control the operating point of the in-wheel motor (300) to switch to the first quadrant, so that the vehicle can be switched to the driving mode.;

[0071] Among the multi-mode switching rules of the integrated power drive and brake in-wheel system, the multi-mode switching rules of the integrated power drive and brake in-wheel system are composed of three main bodies, namely the drive layer, the service braking layer, and the parking braking layer. Among them, the drive layer is composed of drive modes, the service braking layer is composed of pure electric braking mode, compound braking mode, and reverse braking mode, and the parking braking layer is composed of parking braking modes for three scenarios: flat ground parking brake, slope parking brake with the vehicle head facing upward, and slope parking brake with the vehicle head facing downward. As Figure 6As shown in the figure, the dashed boxes represent the decision levels, and the solid boxes represent the specific working modes. The switching between decision levels is achieved through decision paths, and the switching between specific working modes is achieved through control paths. Among them, the thick arrows represent decision paths, the thin solid arrows represent control paths, specifically indicating that the electromagnetic clutch (600) is in the active state at this time, and the thin dashed arrows represent control paths, specifically indicating that the electromagnetic clutch (600) is in the locked state at this time. The numbers in the circles represent the quadrants where the operating points of the in-wheel motor (300) are located under these control paths. When the vehicle starts, the system enters the parking brake layer, that is, the vehicle is in the parking brake state. At this time, the driver decides whether to drive the vehicle or end the use of the vehicle. If the driver chooses to drive the vehicle, the system enters the driving layer, that is, the vehicle is in the driving state. During driving, the system can automatically or according to the driver's intention switch between the driving layer and the driving brake layer to complete the driving task. When the vehicle decelerates to zero speed under the driving brake state, the system can automatically or according to the driver's intention choose to drive again or stop. Here, it is mainly considered that there may be scenarios such as waiting for traffic lights or other short-term stops. If the driver chooses to drive again, the system returns to the driving layer, that is, the vehicle returns to the driving state. If the driver chooses to stop, the system enters the parking brake layer, that is, the vehicle is in the parking brake state. In addition, whether it is the driving brake layer or the parking brake layer, it is necessary to ensure that the electronic wedge brake (500) has completed the return operation before successfully switching to the driving layer.

[0072] The specific process of the multi-mode switching rule for the above-mentioned integrated drive and brake in-wheel electric system based on multiplexing is as follows:

[0073] Step 0: Start;

[0074] Step 1: Enter the parking brake layer and execute Step 2;

[0075] Step 2: Select to drive the vehicle or end the use of the vehicle. If the driver chooses to drive the vehicle, execute Step 3. If the driver chooses to end the use of the vehicle, execute Step 9;

[0076] Step 3: Enter the driving layer and execute Step 4;

[0077] Step 4: Determine whether there is a braking requirement. If yes, execute Step 5. If no, execute Step 3;

[0078] Step 5: Enter the driving brake mode and execute Step 6;

[0079] Step 6: Determine whether there is a driving requirement. If yes, execute Step 3. If no, execute Step 7;

[0080] Step 7: Reduce the vehicle speed to zero through driving brake and execute Step 8;

[0081] Step 8: Select to restart the vehicle or stop. If restarting the vehicle is selected, go to Step 3; if stopping is selected, go to Step 1;

[0082] Step 9: End.

[0083] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described herein. Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A control method for a multiplexed power drive and brake integrated electric wheel system, characterized in that, The content includes: The structural scheme of the integrated electric wheel system with reused power drive and braking; The multi-mode functions and application scenario division based on the integrated electric wheel system with reused power drive and braking; The design of the multi-mode switching control method based on the integrated electric wheel system with reused power drive and braking; The formulation of the multi-mode switching rules based on the integrated electric wheel system with reused power drive and braking.

2. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 1, wherein The structural scheme of the integrated electric wheel system with reused power drive and braking is characterized by including: The integrated electric wheel system with reused power drive and braking consists of a wheel unit (100), a steering knuckle (200), a hub motor (300), a planetary gear reducer (400), an electronic wedge brake (500), and an electromagnetic clutch (600); The wheel unit (100) includes a tire, a rim, a spoke, and a brake disc, and is mainly used to support the vehicle load and transmit driving and braking torques, providing space for the high-integration layout of each system inside; The steering knuckle (200) is an important part of the suspension, and is connected to the upper and lower double wishbones through ball pins. It is mainly used to connect the integrated electric wheel system with reused power drive and braking to the vehicle suspension and transmit forces and torques. There is a through hole in the middle for installing the hub motor, and a thick boss and bolt holes are provided on the left for installing the electronic wedge brake; The hub motor (300) is a low-speed inboard motor, which is used to provide the execution torque for the driving and braking conditions of the integrated electric wheel system with reused power drive and braking, and at the same time serves as the only power source for driving and braking work. There is a through shaft at the rear side of the housing, which is connected to the through hole in the middle of the steering knuckle (200) by interference fit and fixed by bolts. There are threaded holes on the front side of the housing for installing the electromagnetic clutch; The planetary gear reducer (400) includes components such as an input shaft, a sun gear, a planetary gear, a planetary carrier, a ring gear, a reducer housing, and angular contact ball bearings. The input shaft is splined to the hub motor (300) to transmit the torque output by the hub motor (300) and achieve speed reduction and torque increase. The planetary carrier is provided with a positioning pin for installing the wheel unit (100) and is fixed by a flange nut; The electronic wedge brake (500) includes components such as an electronic wedge brake support seat, an electronic wedge brake upper cover, a driven wedge block, a driving wedge block, a friction lining, and an electronic wedge brake return rubber block, and is used to provide the braking torque for the braking condition of the integrated electric wheel system with reused power drive and braking. The driving wedge block is provided with a short shaft connected to the short shaft sleeve at the upper end of the ring gear of the planetary gear reducer (400). In the braking condition, the electronic wedge brake (500) can drive the driving wedge block to push the driven wedge block through the movement of the ring gear of the planetary gear reducer (400), and finally clamp the brake disc of the wheel unit (100) with the friction lining to achieve the braking function; Electromagnetic clutch (600), including components such as rollers, clutch outer hub, clutch inner hub, coil winding, electromagnetic clutch return rubber block, fixed locking pin, etc. There are lugs on both sides of the clutch outer hub, which are connected to the front side of the hub motor (300) housing through screws. The clutch inner hub is in transitional fit connection with the middle hollow shaft provided on the ring gear of the planetary gear reducer (400). By controlling the on / off of the current on the coil winding, the working state of the electromagnetic clutch (600) is determined to achieve the switching of multiple drive and brake modes. When the electromagnetic clutch (600) is in the locked state, it will clamp the ring gear of the planetary gear reducer (400) to keep it stationary. When the electromagnetic clutch (600) is in the active state, the ring gear of the planetary gear reducer (400) can rotate freely.

3. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 2, characterized in that, The multi-mode functions and application scenario division of the integrated electric wheel system based on multiplexed power drive and brake are characterized by including: The working modes of the integrated electric wheel system based on multiplexed power drive and brake are mainly divided into drive mode, pure electric brake mode, compound brake mode, reverse brake mode, and parking brake mode; Drive mode, divided into forward drive and reverse drive, which are respectively applied to the scenarios of vehicle forward driving and reverse driving. In the following text, the "drive mode" and "drive", without special instructions, default to forward drive behavior; Pure electric brake mode means that the vehicle's braking torque is completely provided by electric braking, mainly applied to braking scenarios at medium and low speeds and braking scenarios at high speeds but with small braking intensities; Compound brake mode means that the vehicle's braking torque is jointly provided by electric braking and mechanical friction braking, mainly applied to braking scenarios at extremely low speeds and braking scenarios at high speeds with large braking intensities. Due to considering the motor working characteristics and motor efficiency limitations in this scenario, it results that single electric braking is not sufficient to meet the braking requirements at this time. Therefore, mechanical friction braking needs to be additionally introduced on the basis of electric braking to meet the braking requirements; Reverse brake mode is mainly applied to the braking scenario of vehicle reverse driving. Since the vehicle speed is usually extremely low under the reverse braking condition and the hub motor (300) works in a low-efficiency range, resulting in a low electric braking intensity and being unable to complete a fast and efficient reverse braking action, mechanical friction braking is introduced and the compound braking method is used for braking; Parking brake mode is divided into flat ground parking brake, slope parking brake with the front of the vehicle facing up, and slope parking brake with the front of the vehicle facing down, which are respectively applied to the braking scenarios of flat ground parking, slope parking with the front of the vehicle facing up, and slope parking with the front of the vehicle facing down.

4. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 3, characterized in that, The design of the multi-mode switching control method for the integrated electric wheel system based on multiplexed power drive and brake is characterized by including: The design of the multi-mode switching control method for the integrated electric wheel system based on multiplexed power drive and brake mainly includes the design of control methods for drive mode, pure electric brake mode, compound brake mode, reverse brake mode, and parking brake mode; Define the rotation direction reference system. When the wheel unit (100) moves forward in the positive direction, its own rotation direction around the rotation axis is the positive rotation direction.

5. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 4, characterized in that, The design of the driving mode control method for the integrated electric wheel system based on reusable power drive and brake is characterized by including: The driving mode control method. When working in the forward driving condition, the hub motor (300) is controlled to work in the first quadrant, in a state of positive rotational speed and positive torque. When working in the reverse driving condition, the hub motor (300) is controlled to work in the third quadrant. For the driving mode in both forward and reverse driving conditions, the electromagnetic clutch (600) is controlled to be in the locked state.

6. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 4, characterized in that, The design of the pure electric braking mode control method for the integrated electric wheel system based on reusable power drive and brake is characterized by including: The pure electric braking mode control method controls the in-wheel motor (300) to operate in the fourth quadrant, in a state of positive rotational speed and negative torque, and controls the electromagnetic clutch (600) to be in a locked state. At this time, the total vehicle braking torque is completely provided by electric braking, and the ratio of the output torque of the in-wheel motor (300) to the total braking torque is where k is the characteristic coefficient of the planetary gear reducer (400).

7. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 6, wherein, The design of the composite braking mode control method for the integrated electric wheel system based on reusable power drive and brake is characterized by including: The composite braking mode is divided into an efficiency type composite braking mode and an energy-saving type composite braking mode according to whether the ratio of the electric braking torque to the mechanical friction braking torque is adjustable, and can be set according to the driver's own preference; In the efficiency type composite braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a fixed ratio, and at this time, the proportion of the mechanical braking torque in the total braking torque reaches the maximum value, mainly pursuing the driving performance of the whole vehicle and experiencing the driving pleasure; In the energy-saving type composite braking mode, the electric braking torque and the mechanical friction braking torque are distributed in a variable ratio. On the premise of meeting the braking demand, as much braking torque as possible is distributed to the electric braking, and energy-saving driving is realized through braking energy recovery to improve the economy of the whole vehicle; Efficient composite braking mode control method, which controls the in-wheel motor (300) to operate in the fourth quadrant, in a positive rotational speed and negative torque state, and controls the electromagnetic clutch (600) to be in an active state throughout the process. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to clamp the brake disc of the wheel unit (100), applying mechanical friction braking. At this time, the vehicle braking torque is provided jointly by mechanical friction braking and electric braking, and the ratio of the torque magnitudes of the two is a fixed value. λ is related to the internal parameters of the electronic wedge brake (500), such as the transmission ratio and mechanical efficiency, etc. The ratio of the output torque of the in-wheel motor (300) to the total braking torque magnitude is The total braking torque output can be controlled by adjusting the torque output of the in-wheel motor (300). When canceling the braking, first control the operating point of the in-wheel motor (300) to quickly switch to the first quadrant. At this time, the ring gear of the planetary gear reducer (400) rotates in reverse, driving the active wedge block of the electronic wedge brake (500) back to the center position. This step is briefly called "returning to position". At this time, the electronic wedge brake (500) will automatically separate from the brake disc of the wheel unit (100), and then quickly control the electromagnetic clutch (600) to lock. Energy-saving composite braking mode control method, which controls the in-wheel motor (300) to operate in the fourth quadrant, in a state of positive rotational speed and negative torque. Different from the efficiency-type composite braking mode, the electromagnetic clutch (600) is not in an active state throughout the process, but its state switching is controlled in real time according to the target ratio of the electric braking torque to the mechanical friction braking torque. Since in the composite braking mode, the proportion of the mechanical friction braking in the total braking torque depends on the position of the active wedge of the electronic wedge brake (500), and thus depends on the angle turned by the ring gear of the planetary gear reducer (400), first control the electromagnetic clutch (600) to be in an active state, and the ring gear of the planetary gear reducer (400) starts to reverse. After it turns a certain angle, quickly control the electromagnetic clutch (600) to switch to the locked state, fixing the position of the ring gear of the planetary gear reducer (400) at this time, then the mechanical friction braking torque and the electric braking torque can be controlled to be in any ratio. The relationship is that the ratio of the output torque of the in-wheel motor (300) to the total braking torque is The total braking torque output can be controlled by adjusting the torque output of the in-wheel motor (300). When canceling the braking, first control the operating point of the in-wheel motor (300) to quickly switch to the first quadrant, control the electromagnetic clutch (600) to be in an active state, so that the electronic wedge brake (500) completes the return, and then quickly control the electromagnetic clutch (600) to lock.

8. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 7, characterized in that, The design of the reverse braking mode control method for the integrated electric wheel system based on reusable power drive and brake is characterized by including: The reverse braking mode. The hub motor (300) is controlled to work in the second quadrant, in a state of negative rotational speed and positive torque. The electromagnetic clutch (600) is controlled to be in the active state throughout the process. At this time, the ring gear of the planetary gear reducer (400) rotates in reverse, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to clamp the brake disc of the wheel unit (100) to apply mechanical friction braking. At this time, the vehicle braking torque is provided jointly by mechanical friction braking and electric braking. When canceling the braking, first, the working point of the hub motor (300) is quickly switched to the third quadrant. At this time, the ring gear of the planetary gear reducer (400) rotates forward, enabling the electronic wedge brake (500) to complete the return, and then the electromagnetic clutch (600) is quickly controlled to be locked.

9. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 8, characterized in that, The design of the parking braking mode control method for the integrated electric wheel system based on reusable power drive and brake is characterized by including: The parking braking mode is divided into three types: flat ground parking braking, slope parking braking with the front of the vehicle facing upward, and slope parking braking with the front of the vehicle facing downward; In the flat ground parking brake scenario, the electromagnetic clutch (600) is controlled to be in the active state, and at the same time, the in-wheel motor (300) is controlled to operate in the third quadrant, in a negative rotational speed and negative torque state. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short period of time. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to fully clamp the brake disc of the wheel unit (100). At this time, the electromagnetic clutch (600) is controlled to be in the locked state, completing the flat ground parking brake. When the vehicle starts and the parking brake mode needs to be cancelled, the electromagnetic clutch (600) is controlled to be in the active state, and the in-wheel motor (300) is controlled to operate in the first quadrant. Since the vehicle is still regarded as stationary in a short period of time, the ring gear of the planetary gear reducer (400) rotates forward at this time, causing the electronic wedge brake (500) to return to its original position, and then controlling the electromagnetic clutch (600) to be in the locked state. At this time, the vehicle has met the control conditions required for the driving mode and can be directly switched to the driving mode; In the head-down slope parking brake scenario, at this time the vehicle has a tendency to move forward, which can be analogized to the braking scenario at extremely low vehicle speeds in the compound braking mode. The electromagnetic clutch (600) is controlled to be in the active state, and at the same time, the in-wheel motor (300) is controlled to operate in the fourth quadrant, in a positive rotational speed and negative torque state. At this time, the ring gear of the planetary gear reducer (400) rotates forward, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to fully clamp the brake disc of the wheel unit (100). During this process, the vehicle may be accompanied by a slight forward shake. After the vehicle stops stably, the electromagnetic clutch (600) is controlled to be in the locked state, completing the head-down slope parking brake. When the vehicle starts and the parking brake mode needs to be cancelled, the electromagnetic clutch (600) is controlled to be in the active state, and the in-wheel motor (300) is controlled to operate in the first quadrant. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short period of time. At this time, the ring gear of the planetary gear reducer (400) rotates in the reverse direction, causing the electronic wedge brake (500) to return to its original position, and then controlling the electromagnetic clutch (600) to be in the locked state. At this time, the vehicle has met the control conditions required for the driving mode and can be directly switched to the driving mode; In the case of slope parking brake with the vehicle head facing upward, the vehicle has a tendency to move backward at this time, which can be analogized to the braking scenario of the reverse braking mode. The electromagnetic clutch (600) is controlled to be in an active state, and at the same time, the in-wheel motor (300) is controlled to operate in the second quadrant, with a negative rotational speed and a positive torque state. At this time, the ring gear of the planetary gear reducer (400) rotates in reverse, driving the active wedge block of the electronic wedge brake (500) to move, and finally actuating the electronic wedge brake (500) to completely clamp the brake disc of the wheel unit (100). During this process, the vehicle may be accompanied by a slight backward shake. After the vehicle stops stably, the electromagnetic clutch (600) is controlled to be in a locked state to complete the slope parking brake with the vehicle head facing upward. When the vehicle starts and needs to cancel the parking brake mode, the electromagnetic clutch (600) is controlled to be in an active state, and the in-wheel motor (300) is controlled to operate in the third quadrant. Since the vehicle belongs to a large inertia system, it can be regarded as stationary in a short time. At this time, the ring gear of the planetary gear reducer (400) rotates forward, causing the electronic wedge brake (500) to return to its original position. Then, the electromagnetic clutch (600) is controlled to be in a locked state, and then the operating point of the in-wheel motor (300) is switched to the first quadrant, enabling the vehicle to switch to the driving mode.

10. The control method of a multiplexed power drive and brake integrated electric wheel system according to claim 9, characterized in that, The formulation of the multi-mode switching rules for the power drive and brake integrated in-wheel system based on reuse is characterized by including: The multi-mode switching rules for the power drive and brake integrated in-wheel system based on reuse are composed of three main bodies, namely the drive layer, the service brake layer, and the parking brake layer. Among them, the drive layer consists of drive modes, the service brake layer consists of pure electric braking mode, compound braking mode, and reverse braking mode, and the parking brake layer consists of parking brake modes for three scenarios: flat ground parking brake, slope parking brake with the vehicle head facing upward, and slope parking brake with the vehicle head facing downward; When the vehicle starts, the system enters the parking brake layer, that is, the vehicle is in the parking brake state. At this time, the driver decides whether to drive the vehicle or end using the vehicle. If the driver chooses to drive the vehicle, the system enters the drive layer, that is, the vehicle is in the driving state. During driving, the system can automatically or according to the driver's intention switch between the drive layer and the service brake layer to complete the driving task. When the vehicle decelerates to zero speed in the service brake state, the system can automatically or according to the driver's intention choose to drive again or stop. Here, it is mainly considered that there may be scenarios such as waiting for a traffic light or other short-term stops. If the driver chooses to drive again, the system returns to the drive layer, that is, the vehicle returns to the driving state. If the driver chooses to stop, the system enters the parking brake layer, that is, the vehicle is in the parking brake state; In addition, whether it is the service brake layer or the parking brake layer, it is necessary to ensure that the electronic wedge brake (500) has completed the return operation before successfully switching to the drive layer.

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