Corner module drive-by-wire chassis system based on worm and gear dual-function redundancy and control method

Abstract

The invention provides an angle module drive-by-wire chassis system based on worm and gear dual-function redundancy and a control method of the angle module drive-by-wire chassis system. The angle module drive-by-wire chassis system comprises a vehicle control unit VCU7 and at least two angle modules. Each angle module comprises a driving motor, a steer-by-wire motor, a mechanical brake, a worm and gear redundancy device, a first electromagnetic clutch, a second electromagnetic clutch and a third electromagnetic clutch, and the vehicle control unit VCU controls the first electromagnetic clutch, the second electromagnetic clutch and the third electromagnetic clutch to be connected and disconnected; and the working state of the worm and gear redundant device between the redundant steering mode and the redundant braking mode is switched. A four-wheel independent driving steering framework, energy recovery and electronic mechanical braking are integrated, the compactness, safety and self-adaption of a mechanical structure are achieved, the safety, efficiency and maintenance convenience of the vehicle are improved, and then the driving safety and energy utilization efficiency of the whole vehicle are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vehicle chassis mechanical structure, and particularly relates to an angle module drive-by-wire chassis system based on worm gear dual-function redundancy and a control method. BACKGROUND

[0002] With the rapid development of new energy vehicles and intelligent driving technology, the existing vehicle steering and braking systems mostly adopt a separated mechanical design, steering relies on mechanical linkages or semi-drive-by-wire mechanisms, braking is realized through hydraulic or electronic calipers, and the angle module is usually integrated with the hub motor and suspension components. Such a separated design leads to problems such as a large number of mechanical interfaces, increased weight, delayed response, etc. For example, the traditional steering system is easily affected by mechanical wear, braking and steering lack coordination, the integration degree of the angle module is low, and fast modular assembly cannot be realized. In the intelligent driving scenario, these deficiencies may cause safety hazards, such as uneven distribution of braking force during emergency steering. Although the existing technology proposes drive-by-wire steering, it does not involve redundancy and energy recovery integration of mechanical structures, and there is room for improvement. SUMMARY

[0003] In view of the above technical problems, the application provides an angle module drive-by-wire chassis system based on worm gear dual-function redundancy and a control method, which realizes compactness, safety and self-adaptation of mechanical structures, and improves the safety, efficiency and maintenance convenience of vehicles.

[0004] In one mode of the application, four-wheel independent drive steering architecture, energy recovery and electronic mechanical braking are innovatively integrated to realize compactness, safety and self-adaptation of mechanical structures, improve the safety, efficiency and maintenance convenience of vehicles, and further improve the driving safety and energy utilization efficiency of the whole vehicle.

[0005] The application achieves the above technical purposes through the following technical means.

[0006] An angle module drive-by-wire chassis system based on worm gear dual-function redundancy, comprising a vehicle control unit VCU and at least two angle modules;

[0007] Each of the angle modules comprises:

[0008] A hub drive motor for driving the wheels;

[0009] A drive-by-wire steering motor connected with the steering tie rod through a first transmission mechanism;

[0010] A mechanical brake for applying braking force to the brake disc;

[0011] A worm gear redundancy device, comprising a worm gear transmission mechanism, a first electromagnetic clutch, a second electromagnetic clutch, a third electromagnetic clutch and a vertical speed reducer, the worm gear transmission mechanism is used to provide and transmit redundant power, the engagement and disengagement of the first electromagnetic clutch, the second electromagnetic clutch and the third electromagnetic clutch and the vertical speed reducer work together to realize the dual functions of redundant braking and redundant steering.

[0012] The worm gear transmission mechanism comprises a worm drive motor, a worm driven by the worm drive motor, and a power distribution worm gear meshing with the worm, for providing and transmitting redundant power.

[0013] The first electromagnetic clutch is arranged between the vertical speed reducer and the output end of the worm gear transmission mechanism.

[0014] The second electromagnetic clutch is arranged between one output end of the worm gear transmission mechanism and a second transmission mechanism, for transmitting redundant power to the steering tie rod.

[0015] The third electromagnetic clutch is arranged between the vertical speed reducer and a third transmission mechanism, for transmitting redundant power to the mechanical brake.

[0016] The vehicle control unit VCU switches the working state of the worm gear redundancy device between the redundant steering mode and the redundant braking mode by controlling the engagement and disengagement of the first electromagnetic clutch, the second electromagnetic clutch and the third electromagnetic clutch.

[0017] In the above scheme, the number of angle modules is four, which are left front angle module, right front angle module, left rear angle module and right rear angle module.

[0018] The hub drive motor comprises a left front hub drive motor, a right front hub drive motor, a left rear hub drive motor and a right rear hub drive motor.

[0019] The steer-by-wire motor comprises a left front steer-by-wire motor, a right front steer-by-wire motor, a left rear steer-by-wire motor and a right rear steer-by-wire motor.

[0020] Further, the first transmission mechanism is a first rack and pinion reducer, the second transmission mechanism is a second rack and pinion reducer, and the third transmission mechanism is a redundant brake linkage.

[0021] In the above scheme, the mechanical brake comprises a brake motor, a planetary gear reducer and a ball screw mechanism, the brake motor pushes the brake block to extrude the brake disc through the planetary gear reducer and the ball screw mechanism.

[0022] The scheme further comprises a power supply and an inverter; the hub drive motor can be switched to a generator by the VCU to perform an energy recovery mode when the vehicle is sliding or braking, and the generated electric energy is stored in the power supply through the inverter to realize energy recovery.

[0023] A control method for the angular module drive-by-wire chassis system based on the worm gear dual-function redundancy, comprising the following steps:

[0024] Step S1, state acquisition: the vehicle control unit VCU acquires the vehicle running state, driving demand signal and health state of each motor;

[0025] Step S2, mode decision: the vehicle control unit VCU determines the working mode to be executed based on the acquired vehicle running state, driving demand signal and motor health state;

[0026] Step S3, clutch control: the vehicle control unit VCU switches the system to the required working mode by controlling the engagement and disengagement combination of the first electromagnetic clutch, the second electromagnetic clutch and the third electromagnetic clutch according to the determination result.

[0027] In the above scheme, the step S2 of determining the working mode to be executed specifically comprises the following steps:

[0028] The vehicle control unit VCU first determines whether there is a braking demand or a steering demand;

[0029] If there is a braking demand, it is further determined whether the mechanical brake of the corresponding angular module is healthy, if yes, the drive-by-wire braking mode is selected, and the vehicle control unit VCU controls the mechanical brake to work; if not, the redundancy braking mode is selected if the braking function of the corresponding worm gear redundancy device is healthy; the vehicle control unit VCU controls the first electromagnetic clutch and the third electromagnetic clutch to engage, and the worm drive motor power is transmitted to the mechanical brake through the worm gear transmission mechanism and the vertical reducer;

[0030] If there is a steering demand, it is further determined whether the drive-by-wire motor of the corresponding angular module is healthy, if yes, the drive-by-wire steering mode is selected, and the vehicle control unit VCU controls the drive-by-wire motor and the first rack and pinion reducer to work; if not, the redundancy steering mode is selected if the steering function of the corresponding worm gear redundancy device is healthy, and the vehicle control unit VCU controls the first electromagnetic clutch and the second electromagnetic clutch to engage, and the worm drive motor power is transmitted to the second rack and pinion reducer through the worm gear transmission mechanism;

[0031] If there is no active braking and steering demand, and the vehicle is in coasting or braking state, the energy recovery mode is selected, the vehicle control unit VCU controls the hub drive motor to switch to the generator mode, and the generated electric energy is stored in the power supply through the inverter.

[0032] In the above scheme, in the step S2, if it is judged that one or more corner modules lose steering ability or braking ability, a degraded mode is executed, including the following steps:

[0033] When the steer-by-wire motor and the worm and gear redundancy device of a certain corner module both fail, the vehicle control unit VCU controls the steer-by-wire motor of the remaining healthy corner module itself or realizes steering by engaging the first electromagnetic clutch and the second electromagnetic clutch and using the worm drive motor power, and executes two-wheel steering mode.

[0034] If the mechanical brake and the worm and gear redundancy device of the left front corner module and the right front corner module both fail, or the mechanical brake and the worm and gear redundancy device of the left rear corner module and the right rear corner module both fail, the vehicle control unit VCU controls the mechanical brake of the remaining healthy corner module itself or realizes braking by engaging the first electromagnetic clutch and the third electromagnetic clutch and using the worm drive motor power, and executes two-wheel braking mode.

[0035] In the above scheme, in the step S2, if the vehicle control unit VCU detects an emergency braking signal or if the left front corner module and the right rear corner module lose steering ability at the same time, or the right front corner module and the left rear corner module lose steering ability, the emergency braking mode is switched to; the vehicle control unit VCU controls the healthy mechanical brake of all corner modules to output the maximum braking force, and for the corner module whose mechanical brake is not healthy, if its worm and gear redundancy device is healthy, the worm drive motor power is introduced by engaging the first electromagnetic clutch and the third electromagnetic clutch to provide the maximum redundant braking force.

[0036] In the above scheme, when the vehicle control unit VCU switches to the redundancy mode, the degraded mode or the emergency braking mode, a warning information is sent to the vehicle operation panel and an intelligent voice broadcast is performed.

[0037] Compared with the prior art, the beneficial effects of the present application are:

[0038] 1. The present application integrates the steering actuator, the brake actuator and the corner module unit, innovatively combines the four-wheel independent drive steering frame, energy recovery and electronic mechanical brake, realizes the compactness, safety and self-adaptation of the mechanical structure, improves the safety, efficiency and maintenance convenience of the vehicle, and further improves the driving safety and energy utilization efficiency of the whole vehicle. It is suitable for electric vehicles, intelligent driving vehicles and other fields.

[0039] 2. The worm gear redundancy device is formed by the cooperation of the worm gear transmission mechanism, three groups of electromagnetic clutches and the vertical speed reducer, and provides double functional redundancy in the mechanical level for steering and braking. When a single or multiple actuators fail, the basic steering and braking ability of the vehicle can still be guaranteed, and the functional safety level of the automatic driving system is greatly improved.

[0040] 3. The drive, steering, braking and redundancy mechanism are integrated in the corner module, which is compact in structure, reduces the chassis wire harness and mechanical connection, reduces the weight and assembly complexity, and is convenient for modular production and replacement.

[0041] 4. The hub drive motor can be directly used as a generator for efficient energy recovery during vehicle coasting and braking, improving the energy utilization rate of the vehicle and extending the cruising range.

[0042] 5. Through the centralized intelligent control of the vehicle control unit VCU, the system can seamlessly and smoothly switch between multiple working modes according to the real-time working conditions and health conditions, adapt to various driving scenes and failure conditions, and provide timely warning for the driver. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The structure diagram of the corner module drive-by-wire chassis system based on the worm gear double functional redundancy according to an embodiment of the present application is shown.

[0044] Figure 2 The left front corner module according to an embodiment of the present application is shown.

[0045] Figure 3 The right front corner module according to an embodiment of the present application is shown.

[0046] Figure 4 The left rear corner module according to an embodiment of the present application is shown.

[0047] Figure 5 The right rear corner module according to an embodiment of the present application is shown.

[0048] Figure 6 The control method flow chart of the corner module drive-by-wire chassis system based on the worm gear double functional redundancy according to an embodiment of the present application is shown.

[0049] In the figure, 1, left front corner module; 2, left rear corner module; 3, right rear corner module; 4, power supply; 5, inverter; 6, right front corner module; 7, VCU; 8, wheel; 9, brake disc; 10, knuckle; 11, trapezoidal arm; 12, drive shaft; 13, left front wheel hub drive motor; 14, vertical speed reducer; 15, left front first electromagnetic clutch; 16, left front worm and gear transmission mechanism; 17, left front second electromagnetic clutch; 18, first rack and pinion reducer; 19, left front steer-by-wire motor; 20, second rack and pinion reducer; 21, tie rod; 22, left front third electromagnetic clutch; 23, redundant brake link; 24, mechanical brake; 25, right front wheel hub drive motor; 26, right front third electromagnetic clutch; 27, right front worm and gear transmission mechanism; 28, right front second electromagnetic clutch; 29, right front steer-by-wire motor; 30, right front first electromagnetic clutch; 31, left rear steer-by-wire motor; 32, left rear second electromagnetic clutch; 33, left rear worm and gear transmission mechanism; 34, left rear first electromagnetic clutch; 35, left rear wheel hub drive motor; 36, left rear third electromagnetic clutch; 37, right rear steer-by-wire motor; 38, right rear third electromagnetic clutch; 39, right rear wheel hub drive motor; 40, right rear first electromagnetic clutch; 41, right rear worm and gear transmission mechanism; 42, right rear second electromagnetic clutch. DETAILED DESCRIPTION

[0050] Embodiments of the present application are described in detail below with reference to examples illustrated in the attached drawings, in which the same or similar components have the same or similar designations throughout the various figures. The embodiments described below are examples intended to explain the present application, and should not be understood as limiting the present application.

[0051] In the description of the application, it is to be understood by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0052] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] Figure 1 A preferred embodiment of the angular module drive-by-wire chassis system based on worm gear double-function redundancy of the application is shown, which comprises a vehicle control unit VCU 7 and at least two angular modules;

[0054] Each of the angular modules comprises:

[0055] A hub drive motor for driving the wheels 8;

[0056] A drive-by-wire steering motor connected with the steering tie rod 21 through a first transmission mechanism;

[0057] A mechanical brake 24 for applying a braking force to the brake disc 9;

[0058] A worm gear redundancy device, comprising a worm gear transmission mechanism 16, 27, 33, 41 for providing and transmitting redundancy power, a first electromagnetic clutch 15, 30, 34, 40, a second electromagnetic clutch 17, 28, 32, 42, a third electromagnetic clutch 22, 26, 36, 38 and a vertical reducer 14, the engagement and disengagement of the first electromagnetic clutch 15, 30, 34, 40, the second electromagnetic clutch 17, 28, 32, 42, the third electromagnetic clutch 22, 26, 36, 38 and the vertical reducer 14 work together to realize the dual functions of redundancy braking and redundancy steering.

[0059] The worm gear transmission mechanism 16, 27, 33, 41 comprises a worm drive motor, a worm driven by the worm drive motor, and a power distribution worm gear meshing with the worm, for providing and transmitting redundancy power.

[0060] The first electromagnetic clutch 15, 30, 34, 40 is arranged between the output end of the worm gear transmission mechanism and the vertical reducer 14.

[0061] The second electromagnetic clutch 17, 28, 32, 42 is arranged between the other output end of the worm gear transmission mechanism and the second transmission mechanism, for transmitting redundancy power to the steering tie rod 21.

[0062] The third electromagnetic clutch 22, 26, 36, 38 is arranged between the vertical reducer 14 and the third transmission mechanism, for transmitting redundancy power to the mechanical brake 24.

[0063] The vehicle control unit VCU 7 switches the redundancy braking function and the redundancy steering function of the worm gear redundancy device by controlling the engagement and disengagement of the first electromagnetic clutch, the second electromagnetic clutch and the third electromagnetic clutch.

[0064] The first transmission mechanism is a first rack and pinion reducer 18; the second transmission mechanism is a second rack and pinion reducer 20; the third transmission mechanism is a redundancy brake linkage 23. The vertical reducer 14 transmits driving torque from the worm connecting shaft to the redundancy brake linkage 23 through a pair of bevel gears to provide redundancy braking force.

[0065] The redundancy function of the worm gear redundancy device is as follows, redundancy brake: the worm drive motor transmits torque to the worm, then the worm transmits torque to the worm gear, the worm gear transmits torque to the redundancy brake connecting rod through the first electromagnetic clutch, the three electromagnetic clutch engagement and the vertical speed reducer 14, the brake connecting rod transmits torque to the mechanical brake to achieve the effect of redundancy brake; redundancy steering: the worm drive motor transmits torque to the worm, then the worm transmits torque to the worm gear, the worm gear transmits torque to the output shaft, then the output shaft transmits torque to the second gear rack reducer through the second electromagnetic clutch engagement, and finally the torque is transmitted to the steering tie rod to achieve the effect of redundancy steering.

[0066] The mechanical brake 24 includes a brake motor, a planetary gear reducer and a ball screw mechanism, the brake motor pushes the brake block to extrude the brake disc 9 through the planetary gear reducer and the ball screw mechanism.

[0067] The worm gear double-function redundancy based angle module drive-by-wire chassis system further comprises a power supply 4 and an inverter 5; the power supply 4 is used for storing energy and releasing when needed. The inverter 5 is installed between the hub drive motor and the power supply 4, mainly responsible for converting the alternating current generated in the energy recovery process into storable direct current, and converting the stored direct current back into alternating current when needed, while ensuring power regulation, frequency and phase synchronization, and providing overload and short circuit protection, thereby improving the efficiency of energy recovery and the safety of the system. The hub drive motor can be switched to a generator by the VCU 7 to perform an energy recovery mode when the vehicle is coasting or braking, and the generated electrical energy is stored in the power supply 4 through the inverter 5 to achieve energy recovery.

[0068] In one specific embodiment of the present application, preferably, four angle modules are included, which are left front angle module 1, right front angle module 6, left rear angle module 2 and right rear angle module 3, in particular:

[0069] As Figure 2As shown, the left front corner module 1 includes a wheel 8, a brake disc 9, a steering knuckle 10, a trapezoidal arm 11, a drive shaft 12, a left front wheel hub drive motor 13, a vertical reducer 14, a left front first electromagnetic clutch 15, a left front worm and gear transmission mechanism 16, a left front second electromagnetic clutch 17, a first rack and pinion reducer 18, a left front steer-by-wire motor 19, a second rack and pinion reducer 20, a tie rod 21, a left front third electromagnetic clutch 22, a redundant brake linkage 23, and a mechanical brake 24. The steering knuckle 10 is mainly used to transmit steering torque to make the wheel 8 turn, and is connected to the trapezoidal arm 11 through a ball head. The trapezoidal arm 11 is connected to the steering knuckle 10 at one end and connected to the tie rod 21 at the other end, and is used to transmit steering torque. The drive shaft 12 is located between the wheel hub drive motor and the wheel, and is mainly used to transmit driving torque. It is shorter than the traditional half shaft, and only covers the distance within the corner module.

[0070] The positions and connection relationships of the internal components of the left front corner module 1 are as follows:

[0071] Overall layout and drive path: the left front wheel hub drive motor 13 is the core power source of the left front corner module 1, and its output shaft is directly connected to the wheel 8 through the drive shaft 12 for providing driving force. The brake disc 9 is fixedly installed on the hub of the wheel 8.

[0072] Steering system path: the left front steer-by-wire motor 19 is the main steering actuator, and its output end is directly connected to the input gear of the first rack and pinion reducer 18. The first rack and pinion reducer 18 is installed on the tie rod 21, and converts the rotary motion of the steering motor into the linear motion of the tie rod 21. The two ends of the tie rod 21 are connected to the wheel 8 through the trapezoidal arm 11 and the steering knuckle 10 respectively, so as to transmit the steering torque to the wheel and realize steering.

[0073] Redundancy system and power distribution hub: the left front worm and gear transmission mechanism 16 is the redundancy power hub of the entire corner module, wherein the worm drive motor provides redundancy power, which is transmitted to the redundant brake and the redundant steering through the left front first electromagnetic clutch 15 and the left front second electromagnetic clutch 17.

[0074] Redundant steering path: one output end of the worm and gear transmission mechanism 16 is connected to the second rack and pinion reducer 20 through the left front second electromagnetic clutch 17. When the second electromagnetic clutch 17 is engaged, the worm drive motor power can be transmitted to the tie rod 21 through this path to realize redundant steering.

[0075] Redundant brake path: the other output of the worm gear mechanism 16 is connected to the vertical reducer 14 through the left front first electromagnetic clutch 15. The vertical reducer 14 rotates the power 90 degrees inside through a pair of bevel gears, and its output is connected to the redundant brake connecting rod 23 through the left front third electromagnetic clutch 22. The redundant brake connecting rod 23 finally transmits power to the mechanical brake 24 to generate redundant braking force.

[0076] The mechanical brake 24 is independently installed, and the driving brake block directly extrudes the brake disc 9 to provide the main braking force.

[0077] As shown in Figure 3 The right front corner module 6 includes a wheel 8, a brake disc 9, a knuckle 10, a trapezoidal arm 11, a drive shaft 12, a right front wheel hub drive motor 25, a vertical reducer 14, a right front first electromagnetic clutch 30, a right front worm gear mechanism 27, a right front second electromagnetic clutch 28, a first rack and pinion reducer 18, a right front steer-by-wire motor 29, a second rack and pinion reducer 20, a tie rod 21, a right front third electromagnetic clutch 26, a redundant brake connecting rod 23, and a mechanical brake 24. The mechanical configuration of the right front corner module 6 is centrally symmetrically arranged with the left front corner module 1, and the positions and connection relationships of the internal components are as follows:

[0078] Overall layout and drive path: the right front wheel hub drive motor 25 is the core power source of the right front corner module 6, and its output shaft is directly connected to the wheel 8 through the drive shaft 12 to provide driving force. The brake disc 9 is fixedly installed on the hub of the wheel 8.

[0079] Steering system path: the right front steer-by-wire motor 29 is the main steering actuator, and its output is directly connected to the input gear of the first rack and pinion reducer 18. The first rack and pinion reducer 18 is installed on the tie rod 21 to convert the rotary motion of the steering motor into the linear motion of the tie rod 21. The two ends of the tie rod 21 are connected to the wheel 8 through the trapezoidal arm 11 and the knuckle 10, respectively, so as to transmit the steering torque to the wheel to realize steering.

[0080] Redundant system and power distribution hub: the right front worm gear mechanism 27 is the redundant power hub of the corner module, in which the worm drive motor provides redundant power, which is transmitted to the redundant brake and the redundant steering through the right front first electromagnetic clutch 30 and the right front second electromagnetic clutch 28.

[0081] Redundant steering path: one output of the right front worm gear mechanism 27 is connected to the second rack and pinion reducer 20 through the right front second electromagnetic clutch 28. When the second electromagnetic clutch 28 is engaged, the worm drive motor power can be transmitted to the steering tie rod 21 through this path, realizing redundant steering.

[0082] Redundant braking path: the other output of the right front worm gear mechanism 27 is connected to the vertical reducer 14 through the right front first electromagnetic clutch 30. Inside the vertical reducer 14, the power is rotated by 90 degrees through a pair of bevel gears, and the output end is connected to the redundant braking connecting rod 23 through the right front third electromagnetic clutch 26. The redundant braking connecting rod 23 finally transmits power to the mechanical brake 24, making it generate redundant braking force.

[0083] As shown in Figure 4 The left rear corner module 2 includes: a wheel 8, a brake disc 9, a steering knuckle 10, a trapezoidal arm 11, a drive shaft 12, a left rear hub drive motor 35, a vertical reducer 14, a left rear first electromagnetic clutch 34, a left rear worm gear mechanism 33, a left rear second electromagnetic clutch 32, a first rack and pinion reducer 18, a left rear steer-by-wire motor 31, a second rack and pinion reducer 20, a steering tie rod 21, a left rear third electromagnetic clutch 36, a redundant braking connecting rod 23 and a mechanical brake 24. The left rear corner module 2 is consistent with the aforementioned corner module in mechanical configuration and functional principle, and the positions and connection relationships of the internal components are as follows:

[0084] Overall layout and drive path: the left rear hub drive motor 35 is the core power source of the corner module, and its output shaft is directly connected to the wheel 8 through the drive shaft 12 to provide driving force. The brake disc 9 is fixedly installed on the hub of the wheel 8.

[0085] Steering system path: the left rear steer-by-wire motor 31 is the main steering actuator, and its output end is directly connected to the input gear of the first rack and pinion reducer 18. The first rack and pinion reducer 18 is installed on the steering tie rod 21 to convert the rotary motion of the steering motor into the linear motion of the steering tie rod 21. The two ends of the steering tie rod 21 are connected to the wheel 8 through the trapezoidal arm 11 and the steering knuckle 10 respectively, so as to transmit the steering torque to the wheel and realize steering.

[0086] Redundant system and power distribution hub: the left rear worm gear mechanism 33 is the redundant power hub of the corner module, wherein the worm drive motor provides redundant power, which is transmitted to the redundant braking and the redundant steering through the left rear first electromagnetic clutch 34 and the left rear second electromagnetic clutch 32.

[0087] Redundant steering path: one output of the right rear worm and gear mechanism 41 is connected to the second rack and pinion reducer 20 through the right rear second electromagnetic clutch 42. When the right rear second electromagnetic clutch 42 is engaged, the worm drive motor power can be transmitted to the steering tie rod 21 through this path, realizing redundant steering.

[0088] Redundant braking path: the other output of the right rear worm and gear mechanism 41 is connected to the vertical reducer 14 through the right rear first electromagnetic clutch 40. The output of the vertical reducer 14 is connected to the redundant braking linkage 23 through the right rear third electromagnetic clutch 38 after rotating 90 degrees through a pair of bevel gears inside the vertical reducer 14. The redundant braking linkage 23 finally transmits power to the mechanical brake 24, making it generate redundant braking force.

[0089] As shown in Figure 5 The right rear corner module 3 includes: a wheel 8, a brake disc 9, a steering knuckle 10, a trapezoidal arm 11, a drive shaft 12, a right rear hub drive motor 39, a vertical reducer 14, a right rear first electromagnetic clutch 40, a right rear worm and gear mechanism 41, a right rear second electromagnetic clutch 42, a first rack and pinion reducer 18, a right rear steer-by-wire motor 37, a second rack and pinion reducer 20, a steering tie rod 21, a right rear third electromagnetic clutch 38, a redundant braking linkage 23 and a mechanical brake 24.

[0090] The right rear corner module 3 is consistent with the aforementioned corner module in mechanical configuration and functional principle, and the positions and connection relationships of the internal components are as follows:

[0091] Overall layout and drive path: the right rear hub drive motor 39 serves as the core power source of the corner module, and its output shaft is directly connected to the wheel 8 through the drive shaft 12 for providing driving force. The brake disc 9 is fixedly installed on the hub of the wheel 8.

[0092] Steering system path: the right rear steer-by-wire motor 37 serves as the main steering actuator, and its output end is directly connected to the input gear of the first rack and pinion reducer 18. The first rack and pinion reducer 18 is installed on the steering tie rod 21 to convert the rotary motion of the steering motor into the linear motion of the steering tie rod 21. The two ends of the steering tie rod 21 are connected to the wheel 8 through the trapezoidal arm 11 and the steering knuckle 10, respectively, so as to transmit the steering torque to the wheel, realizing steering.

[0093] Redundant system and power distribution hub: the right rear worm and gear mechanism 41 is the redundant power hub of the corner module, in which the worm drive motor provides redundant power, which is transmitted to the redundant braking and redundant steering through the right rear first electromagnetic clutch 40 and the right rear second electromagnetic clutch 42.

[0094] Redundant steering path: one output of the right rear worm and gear mechanism 41 is connected to the second rack and pinion reducer 20 through the right rear second electromagnetic clutch 42. When the second electromagnetic clutch 40 is engaged, the worm drive motor power can be transmitted to the steering tie rod 21 through this path to achieve redundant steering.

[0095] Redundant braking path: the other output of the right rear worm and gear mechanism 41 is connected to the vertical reducer 14 through the right rear first electromagnetic clutch 40. Inside the vertical reducer 14, the power is rotated by 90 degrees through a pair of bevel gears, and the output end is connected to the redundant braking link 23 through the right rear third electromagnetic clutch 38. The redundant braking link 23 finally transmits power to the mechanical brake 24 to generate redundant braking force.

[0096] From the structure of the left front corner module 1, the right front corner module 6, the left rear corner module 2 and the right rear corner module 3, it can be seen that one output of the left front worm and gear mechanism 16, the right front worm and gear mechanism 27, the left rear worm and gear mechanism 33 and the right rear worm and gear mechanism 41 can be connected to the second rack and pinion reducer 20 through the corresponding left front second electromagnetic clutch 17, the right front second electromagnetic clutch 28, the left rear second electromagnetic clutch 32 and the right rear second electromagnetic clutch 42, for providing redundant steering force; the other output of the left front worm and gear mechanism 16, the right front worm and gear mechanism 27, the left rear worm and gear mechanism 33 and the right rear worm and gear mechanism 41 can pass through the vertical reducer 14 and be connected to the redundant braking link 23 through the corresponding left front third electromagnetic clutch 22, the right front third electromagnetic clutch 26, the left rear third electromagnetic clutch 36 and the right rear third electromagnetic clutch 38, for providing redundant braking force to the mechanical brake 24; the VCU 7 is electrically connected with the left front hub drive motor 13, the right front hub drive motor 25, the left rear hub drive motor 35 and the right rear hub drive motor 39, the left front steer-by-wire motor 19, the right front steer-by-wire motor 29, the left rear steer-by-wire motor 31 and the right rear steer-by-wire motor 37, the mechanical brake 24 and each electromagnetic clutch respectively.

[0097] The control principle of the steer-by-wire system: when steering, the vehicle control unit VCU 7 receives the steering signal and controls the left front steer-by-wire motor 19, the right front steer-by-wire motor 27, the left rear steer-by-wire motor 31 and the right rear steer-by-wire motor 37 to work to drive the first gear rack reducer to transmit the motor steering torque to the wheels 8 through the steering tie rod 21, the trapezoidal arm 11 and the steering knuckle 10 to achieve the purpose of steering, and the vehicle control unit VCU 7 can control the left front second electromagnetic clutch 17, the right front second electromagnetic clutch 28, the left rear second electromagnetic clutch 32 and the right rear second electromagnetic clutch 42 to be connected, and transmit the driving torque from the worm connecting shaft to the second gear rack reducer 20 through the left front worm and gear transmission mechanism 16, the right front worm and gear transmission mechanism 29, the left rear worm and gear transmission mechanism 33 and the right rear worm and gear transmission mechanism 41 to provide redundant steering force.

[0098] The control principle of the brake-by-wire system: when braking, the vehicle control unit VCU 7 receives the braking signal and controls the mechanical brake 24 including the ball screw mechanism connected with the brake motor through the planetary gear reducer to push the brake block to extrude the brake disc 9 to provide mechanical braking force, and the vehicle control unit VCU 7 controls the left front first electromagnetic clutch 15, the right front first electromagnetic clutch 30, the left rear first electromagnetic clutch 34, the right rear first electromagnetic clutch 40, the left front third electromagnetic clutch 22, the right front third electromagnetic clutch 26, the left rear third electromagnetic clutch 36 and the right rear third electromagnetic clutch 38 to be connected, and transmit the torque in the left front worm and gear transmission mechanism 16, the right front worm and gear transmission mechanism 29, the left rear worm and gear transmission mechanism 33 and the right rear worm and gear transmission mechanism 41 to the redundant brake connecting rod 23 through a pair of bevel gears of the vertical reducer 14 to provide redundant braking force.

[0099] The application also provides a control method of the worm and gear dual-function redundant angular module steer-by-wire chassis system, which can switch multiple modes according to the fault conditions and needs of electronic devices.

[0100] The control method of the worm and gear dual-function redundant angular module steer-by-wire chassis system comprises the following steps:

[0101] Step S1, state acquisition: the vehicle control unit VCU 7 acquires the vehicle running state, the driving demand signal and the health state of each motor, for example, whether the signals such as current, temperature and speed fed back by the motor controller are abnormal, whether there is communication timeout;

[0102] Step S2, mode decision: the vehicle control unit VCU 7 judges the working mode to be executed based on the acquired vehicle running state, driving demand signal and motor health state;

[0103] Step S3, clutch control: the vehicle control unit VCU 7 switches the system to the required working mode by controlling the combination of engagement and disengagement of the first, second and third electromagnetic clutches according to the judgment result.

[0104] The step S2 of judging the working mode to be executed specifically includes the following steps:

[0105] The vehicle control unit VCU 7 first judges whether there is a braking demand or a steering demand. When the vehicle has both braking and steering demands, if the system is in the redundant steering mode and a main actuator failure occurs, the vehicle control unit VCU 7 determines that emergency braking is needed, and the vehicle control unit VCU 7 will prioritize braking safety. In this case, the vehicle control unit VCU 7 will calculate the optimal braking force required to maintain vehicle stability based on real-time vehicle state and sensor data, and ensure vehicle stability. The vehicle control unit 7 will interrupt the power supply for redundant steering and immediately switch the power to redundant braking.

[0106] If there is a braking demand, it is further judged whether the mechanical brake 24 of the corresponding angle module is healthy. If it is healthy, the brake-by-wire mode is selected, and the vehicle control unit VCU 7 controls the mechanical brake 24 to work. If it is not healthy but the corresponding worm gear redundant device braking function is healthy, the redundant braking mode is selected. The vehicle control unit VCU 7 controls the first and third electromagnetic clutches to engage, and the worm drive motor power is transmitted to the mechanical brake 24 through the worm gear transmission mechanism 16, 27, 33, 41 and the vertical speed reducer 14.

[0107] If there is a steering demand, it is further judged whether the steer-by-wire motor of the corresponding angle module is healthy. If it is healthy, the steer-by-wire mode is selected, and the vehicle control unit VCU 7 controls the steer-by-wire motor and the first rack and pinion reducer 18 to work. If it is not healthy but the corresponding worm gear redundant device steering function is healthy, the redundant steering mode is selected, and the vehicle control unit VCU 7 controls the first and second electromagnetic clutches to engage, and the worm drive motor power is transmitted to the second rack and pinion reducer 20 through the worm gear transmission mechanism 16, 27, 33, 41.

[0108] If there is no active braking and steering demand, and the vehicle is in a coasting or braking state, the energy recovery mode is selected, and the vehicle control unit VCU 7 controls the hub drive motor to switch to a generator mode, and stores the generated electric energy in the power supply 4 through the inverter 5.

[0109] In the step S2, if it is judged that one or more angle modules lose steering or braking ability, the degradation mode is executed, including the following steps:

[0110] When the steer-by-wire motor and the worm and gear redundant device steering function of a certain corner module both fail, the vehicle control unit VCU 7 controls the steer-by-wire motor of the remaining healthy corner module itself or realizes steering by engaging the first electromagnetic clutch and the second electromagnetic clutch and using the power of the hub drive motor, and executes two-wheel steering mode;

[0111] If the mechanical brake 24 and the worm and gear redundant device braking function of the left front corner module and the right front corner module both fail, or the mechanical brake 24 and the worm and gear redundant device braking function of the left rear corner module and the right rear corner module both fail, the vehicle control unit VCU 7 controls the mechanical brake of the remaining healthy corner module itself or realizes braking by engaging the first electromagnetic clutch and the third electromagnetic clutch and using the power of the worm drive motor, and executes two-wheel braking mode.

[0112] When the left front corner module and the right rear corner module lose steering ability at the same time, or the right front corner module and the left rear corner module lose steering ability, the torque direction is opposite and concentrated, and the diagonal wheels lose steering control, which will form a reverse force arm around the vehicle center of gravity, directly causing severe yaw. At this time, the correction difficulty is extremely high, the yaw torque is perpendicular to the vehicle driving direction, and the conventional steering and braking operation cannot be offset, and the vehicle body stability limit will be broken in a short time. Compared with other combinations, the same side wheel instability often leads to deviation (which can be alleviated by steering fine adjustment), while the diagonal instability is "twisted out of control", and the danger coefficient is higher than that of other combinations. Therefore, in the step S2, if the vehicle control unit VCU 7 detects an emergency braking signal or if the left front corner module and the right rear corner module lose steering ability at the same time, or the right front corner module and the left rear corner module lose steering ability, the emergency braking mode is switched to; the vehicle control unit VCU 7 controls the healthy mechanical brake 24 of all corner modules to output maximum braking force, and for the corner module whose mechanical brake is not healthy, if its worm and gear redundant device braking function is healthy, the first electromagnetic clutch and the third electromagnetic clutch are engaged to introduce the power of the worm drive motor to provide maximum redundant braking force.

[0113] When the vehicle control unit VCU 7 is switched to the redundant mode, the degraded mode or the emergency braking mode, a warning information is sent to the vehicle operation panel and an intelligent voice broadcast is performed.

[0114] The control method of the corner module steer-by-wire chassis system based on the worm and gear double-function redundancy according to the application, in the overall mode switching control architecture, covers the energy recovery mode, the four-wheel independent steering mode, the two-wheel steering mode, the redundant steering mode, the emergency braking mode, the four-wheel independent braking mode, the redundant braking mode, the two-wheel braking mode and the redundant drive mode.

[0115] The overall flow of the control method, as shown in Figure 6 is an intelligent closed-loop control process executed by the vehicle control unit VCU 7 and continuously running: by real-time monitoring to obtain vehicle state information, making mode judgments based on preset decision algorithms, and finally driving the corresponding actuators by controlling the combined state of the electromagnetic clutch, to realize dynamic switching of the working mode, specifically:

[0116] The vehicle control unit VCU 7, as the control core, continuously obtains the vehicle running state (such as vehicle speed, yaw rate), explicit driving demand (such as steering, braking signal), and the health state of each actuator (wheel hub drive motor, steering motor, brake motor) from sensors, buses and other channels.

[0117] The vehicle control unit VCU 7 compares and calculates the above information with the built-in fault diagnosis logic and mode switching strategy to determine the optimal working mode to enter. The decision priority is: emergency fault handling > active driving demand (steering / braking) > energy efficiency optimization (energy recovery).

[0118] According to the decision result, the vehicle control unit VCU 7 outputs specific control instructions. The core action is to control the on-off combination of the first electromagnetic clutch, the second electromagnetic clutch, and the third electromagnetic clutch, so as to intelligently distribute power to the steering system or the braking system, or cut off the redundant path. At the same time, the vehicle control unit VCU 7 will coordinate the control of the corresponding motors (wheel hub drive motor, steer-by-wire motor, brake motor, worm drive motor) to work as needed.

[0119] While and after the mode switching is performed, the vehicle control unit VCU 7 continuously monitors the system feedback. When the system enters any abnormal mode (such as redundancy, degradation or emergency mode), it will immediately issue a warning to the driver through the operation panel and the voice system, forming a human-machine interaction closed loop.

[0120] This closed-loop process ensures that the system can adaptively cope with normal driving, component failure, emergency working conditions and other scenarios, and realizes the unity of safety, energy efficiency and maneuverability.

[0121] The entire system is centrally controlled by the vehicle control unit VCU 7, which monitors the running state of each corner module system in real time, such as whether the steer-by-wire motor is faulty, and selects the appropriate running mode according to different working conditions.

[0122] When the left front steer-by-wire motor 19 fails, the vehicle control unit VCU 7 detects that there is a single corner module failure, and immediately switches to the redundant four-wheel independent steering mode, thereby ensuring that the vehicle can continue to realize the steering function.

[0123] In the normal steering condition, i.e. the left front line-controlled steering motor 19, the right front line-controlled steering motor 27, the left rear line-controlled steering motor 31 and the right rear line-controlled steering motor 37 are not faulty, in the normal urban driving braking condition, the vehicle control unit VCU 7 performs data calculation according to the actual driving state of the vehicle to determine whether to perform the energy recovery mode, the emergency braking mode and the state switching in the form of connection and disconnection of the electromagnetic clutch, so as to realize dynamic switching of the energy recovery mode, the four-wheel independent steering mode, the two-wheel steering mode, the redundant steering mode, the emergency braking mode, the four-wheel independent braking mode, the redundant braking mode, the two-wheel braking mode and the redundant driving mode.

[0124] Energy recovery mode:

[0125] The vehicle control unit VCU 7 performs data calculation according to the actual driving state of the vehicle to determine whether to perform the energy recovery mode, in which the left front hub drive motor 13, the right front hub drive motor 25, the left rear hub drive motor 35 and the right rear hub drive motor 39 perform energy recovery when the vehicle is sliding or braking, so as to convert kinetic energy into electrical energy and store it in the power supply 4.

[0126] The working process of the energy recovery mode is as follows:

[0127] (1) The vehicle control unit VCU 7 determines the braking mode: the vehicle control unit VCU 7 monitors the vehicle driving data in real time, whether to slide or have a brake pedal signal, and determines that the vehicle is in the energy recovery mode.

[0128] (2) The hub drive motor generates electricity: in the energy recovery process, the left front hub drive motor 13, the right front hub drive motor 25, the left rear hub drive motor 35 and the right rear hub drive motor 39 are switched to the generator to perform energy recovery and generate regenerative braking force. The kinetic energy of the vehicle is converted into electrical energy through the transmission system and the hub drive motor.

[0129] (3) Electrical energy storage: the generated electrical energy is converted into direct current through the inverter 5 and stored in the power supply 4 system of the vehicle for future use

[0130] (4) After braking: when the vehicle stops braking or needs to accelerate again, the vehicle control unit VCU 7 controls the system to exit the energy recovery braking mode, and the left front hub drive motor 13, the right front hub drive motor 25, the left rear hub drive motor 35 and the right rear hub drive motor 39 stop generating electricity, and the normal driving mode is restored.

[0131] Four-wheel independent steering mode:

[0132] (1) The vehicle control unit VCU 7 determines the steering type: The vehicle control unit VCU 7 monitors the vehicle driving data in real time, determines that each corner module steer-by-wire motor is healthy, and determines that the steering type is four-wheel independent steering mode.

[0133] (2) Steering motor operation: The vehicle control unit VCU 7 receives a steering signal and controls the left front steer-by-wire motor 19, the right front steer-by-wire motor 27, the left rear steer-by-wire motor 31, and the right rear steer-by-wire motor 37 to work.

[0134] (3) Steering torque transmission: The first rack and pinion reducer 18 transmits the motor steering torque to the wheels 8 through the steering tie rod 21, the trapezoidal arm 11, and the steering knuckle 10 to achieve the purpose of steering.

[0135] (4) Steering end: The vehicle control unit VCU 7 controls the system to exit the four-wheel independent steering mode and restore the normal driving mode.

[0136] Two-wheel steering mode:

[0137] (1) The vehicle control unit VCU 7 determines the steering type: The vehicle control unit VCU 7 monitors the vehicle driving data in real time, determines that the left front corner module, the right front corner module, or the left rear corner module, the right rear corner module steer-by-wire motor is faulty, and the redundant steering motor is also faulty, and determines that the steering type is two-wheel steering mode.

[0138] (2) Steering motor operation: The vehicle control unit VCU 7 receives a steering signal and controls the left front steer-by-wire motor 19, the right front steer-by-wire motor 27, or the left rear steer-by-wire motor 31, the right rear steer-by-wire motor 37 to work.

[0139] (3) Steering torque transmission: The first rack and pinion reducer 18 transmits the motor steering torque to the wheels 8 through the steering tie rod 21, the trapezoidal arm 11, and the steering knuckle 10 to achieve the purpose of steering.

[0140] (4) Steering end: The vehicle control unit VCU 7 controls the system to exit the two-wheel steering mode and restore the normal driving mode.

[0141] Redundant steering mode:

[0142] (1) The vehicle control unit VCU 7 determines the steering type: The vehicle control unit VCU 7 monitors the vehicle driving data in real time, determines whether there is a left front corner module, a right front corner module, a left rear corner module, and a right rear corner module steer-by-wire motor fault, but the worm gear redundant device steering function is healthy, and determines that the steering type is redundant steering mode.

[0143] (2) Electromagnetic clutch works: the vehicle control unit VCU 7 controls the electromagnetic clutch connection of the corresponding fault angle module, taking the left front angle module as an example, the left front second electromagnetic clutch 17 is connected.

[0144] (3) Steering torque transmission: the left front worm and gear transmission mechanism 16 transmits the motor steering torque to the second gear rack reducer 20, the steering tie rod 21, the trapezoidal arm 11 and the steering knuckle 10 through the worm connecting shaft to the wheel 8 to achieve the purpose of steering.

[0145] (4) Steering end: the vehicle control unit VCU 7 controls the system to exit the redundant steering mode and restore the normal driving mode.

[0146] Emergency braking mode:

[0147] (1) The vehicle control unit VCU 7 judges the braking type: the vehicle control unit VCU 7 monitors the vehicle running data in real time, and if emergency braking is needed, such as left front wheel, right rear wheel steer-by-wire motor failure and redundant motor failure, the braking type is switched to emergency braking mode.

[0148] (2) Brake motor works: the vehicle control unit VCU 7 receives the emergency braking signal and controls the four-wheel mechanical brake 24 to work independently and output the maximum mechanical braking force that can keep the vehicle body stable according to the working condition.

[0149] (3) Braking torque transmission: including the ball screw mechanism in the mechanical brake 24 connected with the brake motor through the planetary gear reducer, pushing the brake block to extrude the brake disc to provide the maximum mechanical braking force.

[0150] (4) Braking end: the vehicle control unit VCU 7 controls the system to exit the emergency braking mode and the vehicle stops running.

[0151] Four-wheel independent braking mode:

[0152] (1) The vehicle control unit VCU 7 judges the braking type: the vehicle control unit VCU 7 monitors the vehicle running data in real time, and the vehicle control unit VCU 7 receives the braking signal and judges that each angle module steer-by-wire motor is healthy, then the braking type is switched to emergency braking mode.

[0153] (2) Brake motor works: the vehicle control unit VCU 7 controls the four-wheel mechanical brake 24 to work independently.

[0154] (3) Braking torque transmission: including the ball screw mechanism in the mechanical brake 24 connected with the brake motor through the planetary gear reducer, pushing the brake block to extrude the brake disc to provide the mechanical braking force.

[0155] (4) Brake end: the vehicle control unit VCU 7 controls the system to exit the four-wheel independent braking mode, and the vehicle stops running.

[0156] Two-wheel braking mode:

[0157] (1) The vehicle control unit VCU 7 determines the braking type: the vehicle control unit VCU 7 monitors the vehicle running data in real time, the vehicle control unit VCU 7 receives the braking signal and determines that the left front corner module, the right front corner module or the left rear corner module, the right rear corner module line control brake motor is faulty, and the redundant brake motor is also faulty, then determines that the braking type is two-wheel braking mode.

[0158] (2) Brake motor work: the vehicle control unit VCU 7 controls the left front and right front or left rear and right rear mechanical brake 24 to work.

[0159] (3) Brake torque transmission: including the ball screw mechanism in the mechanical brake 24 connected with the brake motor through the planetary gear reducer, pushing the brake block to extrude the brake disc to provide mechanical braking force.

[0160] (4) Brake end: the vehicle control unit VCU 7 controls the system to exit the two-wheel braking mode, and the vehicle stops running.

[0161] Redundant braking mode:

[0162] (1) The vehicle control unit VCU 7 determines the braking type: the vehicle control unit VCU 7 monitors the vehicle running data in real time, the vehicle control unit VCU 7 receives the braking signal and determines that the left front corner module, the right front corner module or the left rear corner module, the right rear corner module line control brake motor is faulty, but the worm gear redundant device braking function is healthy, then determines that the braking type is redundant braking mode.

[0163] (2) Electromagnetic clutch work: the vehicle control unit VCU 7 controls the electromagnetic clutch connection corresponding to the fault corner module, for example, the left front corner module, the left front first electromagnetic clutch 15 and the left front third electromagnetic clutch 22 are connected.

[0164] (3) Brake torque transmission: the torque of the left front worm gear transmission mechanism 16 motor is transmitted vertically through a pair of bevel gears of the vertical speed reducer 14, the driving torque is vertically transmitted from the worm gear connecting shaft to the redundant brake connecting rod 23 and transmitted to the mechanical brake motor connected through the ball screw mechanism and the planetary gear reducer to provide redundant braking force.

[0165] (4) Brake end: the vehicle control unit VCU 7 controls the system to exit the redundant braking mode, and the vehicle stops running.

[0166] Redundant drive mode:

[0167] (1) The vehicle control unit VCU 7 determines the braking type: The vehicle control unit VCU 7 monitors the vehicle running data in real time, the vehicle control unit VCU 7 receives the driving signal and determines the single corner module or the left front corner module, the right front corner module or the left rear corner module, the right rear corner module wheel hub drive motor fault, but the other wheel hub drive motor is healthy, then determine the driving type as redundancy driving mode.

[0168] (2) The vehicle control unit VCU 7 controls the motor switch: The vehicle control unit VCU 7 controls the wheel hub drive motor of the fault corner module to be closed, and the vehicle control unit VCU 7 comprehensively considers the vehicle dynamics, adjusts the output torque of the remaining healthy wheel hub drive motor, maintains the balance of the whole vehicle driving force and yaw moment, calculates and distributes the driving torque to other healthy wheel hub drive motor, taking the left front corner module fault as an example.

[0169] (3) Distribute driving torque: The vehicle control unit VCU 7 controls the left front wheel hub drive motor 13 to be closed, and redistributes the driving torque to the right front wheel hub drive motor 25, the left rear wheel hub drive motor 35 and the right rear wheel hub drive motor 39.

[0170] (4) Driving end: The vehicle control unit VCU 7 controls the system to exit the redundancy driving mode, and the vehicle stops running.

[0171] In one specific embodiment of the application, the mode switching method of the control method of the corner module drive-by-wire chassis system based on the worm gear double function redundancy is as follows:

[0172] Step 1, the vehicle control unit VCU 7 collects vehicle running data to process and read the current working condition and demand, and reads the health status of each motor.

[0173] Step 2, the vehicle control unit VCU 7 determines the working mode according to the health status of each motor and the working condition demand, and preferentially determines whether there is a braking or steering demand (i.e. whether there is a pedal braking or steering wheel steering signal input), if there is a braking or steering demand, the vehicle control unit VCU 7 switches to the drive-by-wire braking mode or the drive-by-wire steering mode; if the braking or steering motor fails, the redundancy braking mode or the redundancy steering mode is switched.

[0174] Step 3, when the vehicle control unit VCU 7 detects that each module of the vehicle is fault-free, the wheel hub drive motor is switched to a generator according to the working condition, and an energy recovery mode is executed.

[0175] Step 4, in the steer-by-wire mode, if all the angle modules are healthy, the four-wheel independent steering mode is executed; if there is an angle module failure and the worm redundancy device steering function is healthy, the redundancy steering mode is executed; if there is a single angle module loss of steering capability (if both the angle module and the redundancy motor fail, it is considered as loss of steering capability), the two-wheel steering mode is executed; if the left front angle module and the right rear angle module lose steering capability at the same time, or the right front angle module and the left rear angle module lose steering capability at the same time, the emergency braking mode is executed; when the above-mentioned angle module loses steering capability, the vehicle control unit VCU 7 displays a warning on the operation panel, and the intelligent voice broadcasts a warning to prevent the vehicle from losing control.

[0176] Step 5, in the brake-by-wire mode, if it is determined that all the angle modules are healthy, the four-wheel independent braking mode is executed; if there is an angle module failure and the worm redundancy device braking function is healthy, the redundancy braking mode is executed; if the left front angle module and the right rear angle module lose braking capability at the same time, or the right front angle module and the left rear angle module lose braking capability at the same time (if both the angle module and the redundancy motor fail, it is considered as loss of braking capability), the emergency braking mode is executed; if the left front angle module and the right front angle module lose braking capability at the same time, or the left rear angle module and the right rear angle module lose braking capability at the same time, the two-wheel brake-by-wire mode is executed; the vehicle control unit VCU 7 displays a warning on the operation panel, and the intelligent voice broadcasts a warning to prevent the vehicle from losing control.

[0177] Each of the angle modules has a corresponding hub drive motor, a steer-by-wire motor, a worm and gear transmission mechanism, three sets of electromagnetic clutches, a vertical reducer 14, two sets of gear and rack reducers, and related transmission structures. The angle modules can automatically switch to the redundancy system when a failure occurs in braking, steering, etc., to ensure uninterrupted braking and steering capability of the vehicle, greatly improving the safety and reliability of the chassis. At the same time, the hub drive motor can perform efficient energy recovery under normal working conditions, improving energy utilization. The angle module structure is highly integrated, compact in size, easy to assemble and maintain, suitable for different vehicle models, and supports flexible switching of multiple modes. Through the switching of the vehicle control unit VCU 7, the vertical reducer 14, the worm and gear transmission mechanism, and the electromagnetic clutch, the overall mode control architecture covers the energy recovery mode, the four-wheel independent steering mode, the two-wheel steering mode, the redundancy steering mode, the emergency braking mode, the four-wheel independent braking mode, the redundancy braking mode, the two-wheel braking mode, and the redundancy drive mode, effectively improving the energy efficiency, redundancy capability, and automatic driving adaptability of the vehicle.

[0178] It should be understood that although the present specification is described in terms of various embodiments, each of which describes only one implementation, the specification is intended to cover all possible implementations that are within the scope of the application, which is defined by the claims. One skilled in the art will readily recognize from the disclosure herein, that alternative embodiments of the present application can be constructed from a number of approaches already known in the art, which, if desired, can be selected for the implementation of the techniques described herein without departing from the scope of the present application. Accordingly, the application is not intended to be limited to the implementations described herein but is to be accorded the widest scope consistent with the claims.

[0179] The detailed description set forth above is merely illustrative of the application and is not intended to limit the scope of the application as defined in the claims below and equivalents thereof.

Claims

1. A worm-gear dual-function redundant based corner module drive-by-wire chassis system, characterized in that, The vehicle control unit VCU (7) and at least two corner modules are included; Each of the corner modules includes: A hub drive motor for driving a wheel (8); A steer-by-wire motor connected with a steering tie rod (21) through a first transmission mechanism; A mechanical brake (24) for applying a braking force to a brake disc (9); A worm gear redundancy device including a worm gear transmission mechanism (16, 27, 33, 41) for providing and transmitting redundant power, a first electromagnetic clutch (15, 30, 34, 40), a second electromagnetic clutch (17, 28, 32, 42), a third electromagnetic clutch (22, 26, 36, 38) and a vertical speed reducer (14) for engaging and disengaging the first electromagnetic clutch (15, 30, 34, 40), the second electromagnetic clutch (17, 28, 32, 42) and the third electromagnetic clutch (22, 26, 36, 38) and the vertical speed reducer (14) to realize the dual functions of redundant braking and redundant steering; The worm gear transmission mechanism (16, 27, 33, 41) includes a worm drive motor, a worm driven by the worm drive motor, and a power distribution worm gear meshing with the worm for providing and transmitting redundant power; The first electromagnetic clutch (15, 30, 34, 40) is arranged between the output end of the worm gear transmission mechanism and the vertical speed reducer 14; The second electromagnetic clutch (17, 28, 32, 42) is arranged between the other output end of the worm gear transmission mechanism and a second transmission mechanism for transmitting redundant power to the steering tie rod (21); The third electromagnetic clutch (22, 26, 36, 38) is arranged between the vertical speed reducer 14 and a third transmission mechanism for transmitting redundant power to the mechanical brake (24); The vehicle control unit VCU (7) switches the redundant braking function and the redundant steering function of the worm gear redundancy device by controlling the engagement and disengagement of the first electromagnetic clutch, the second electromagnetic clutch and the third electromagnetic clutch.

2. The worm-gear dual-function redundant based corner module drive-by-wire chassis system according to claim 1, characterized in that, The number of corner modules is four, which are left front corner module (1), right front corner module (6), left rear corner module (2) and right rear corner module (3); The hub drive motor includes left front hub drive motor (13), right front hub drive motor (25), left rear hub drive motor (35) and right rear hub drive motor (39); The steer-by-wire motor includes left front steer-by-wire motor (19), right front steer-by-wire motor (29), left rear steer-by-wire motor (31) and right rear steer-by-wire motor (37); The worm gear transmission mechanism includes left front worm gear transmission mechanism (16), right front worm gear transmission mechanism (27), left rear worm gear transmission mechanism (33) and right rear worm gear transmission mechanism (41).

3. The worm-gear dual-function redundant based corner module drive-by-wire chassis system according to claim 2, characterized in that, The first transmission mechanism is a first rack and pinion reducer (18); the second transmission mechanism is a second rack and pinion reducer (20); and the third transmission mechanism is a redundant brake linkage (23).

4. The worm-gear dual-function redundant based corner module drive-by-wire chassis system according to claim 1, wherein, The mechanical brake (24) comprises a brake motor, a planetary gear reducer and a ball screw mechanism, the brake motor pushes brake blocks to extrude the brake disc (9) through the planetary gear reducer and the ball screw mechanism.

5. The worm-gear dual-function redundant based corner module drive-by-wire chassis system according to claim 1 or 2, characterized in that, Further comprising a power supply (4) and an inverter (5); the hub drive motor can be switched to a generator by the VCU (7) to perform an energy recovery mode when the vehicle is sliding or braking, the generated electric energy is stored into the power supply (4) through the inverter (5) to realize energy recovery.

6. A control method for a worm-gear dual-function redundant based corner module drive-by-wire chassis system according to any one of claims 1-5, characterized in that, The method comprises the following steps: Step S1, state acquisition: the vehicle control unit VCU (7) acquires the vehicle running state, driving demand signal and the health state of each motor; Step S2, mode decision: the vehicle control unit VCU (7) judges the working mode to be executed based on the acquired vehicle running state, driving demand signal and motor health state; Step S3, clutch control: the vehicle control unit VCU (7) switches the system to the required working mode by controlling the engagement and disengagement combination of the first electromagnetic clutch, the second electromagnetic clutch and the third electromagnetic clutch according to the judgment result.

7. The control method of the worm-gear dual-function redundant based angular module drive-by-wire chassis system according to claim 6, characterized in that, The judgment of the working mode to be executed in step S2 specifically comprises the following steps: The vehicle control unit VCU (7) first judges whether there is a braking demand or a steering demand; If there is a braking demand, it is further judged whether the mechanical brake (24) of the corresponding angle module is healthy, if it is healthy, the line control braking mode is selected, and the vehicle control unit VCU (7) controls the mechanical brake (24) to work; if it is not healthy but the corresponding worm gear redundancy device braking function is healthy, the redundancy braking mode is selected; the vehicle control unit VCU (7) controls the first electromagnetic clutch and the third electromagnetic clutch to engage, and the worm drive motor power is transmitted to the mechanical brake (24) through the worm gear transmission mechanism (16, 27, 33, 41) and the vertical reducer (14); If there is a steering demand, it is further judged whether the line control steering motor of the corresponding angle module is healthy, if it is healthy, the line control steering mode is selected, and the vehicle control unit VCU (7) controls the line control steering motor and the first gear rack reducer (18) to work; if it is not healthy but the corresponding worm gear redundancy device steering function is healthy, the redundancy steering mode is selected, and the vehicle control unit VCU (7) controls the first electromagnetic clutch and the second electromagnetic clutch to engage, and the worm drive motor power is transmitted to the second gear rack reducer (20) through the worm gear transmission mechanism (16, 27, 33, 41); If there is no active braking and steering demand, and the vehicle is in a sliding or braking state, the energy recovery mode is selected, the vehicle control unit VCU (7) controls the hub drive motor to switch to a generator mode, and stores the generated electric energy into the power supply (4) through the inverter (5).

8. The control method of the worm-gear dual-function redundant based angular module drive-by-wire chassis system according to claim 6, characterized in that, In step S2, if one or more angle modules lose steering or braking capability, a degraded mode is executed, comprising the following steps: When the steer-by-wire motor and the worm and gear redundancy device steering function of a certain corner module both fail, the vehicle control unit VCU (7) controls the steer-by-wire motor of the remaining healthy corner module itself or realizes steering by engaging the first electromagnetic clutch and the second electromagnetic clutch and using the worm drive motor power to realize steering, and executes two-wheel steering mode; If the mechanical brake (24) and the worm and gear redundancy device braking function of the left front corner module and the right front corner module both fail, or the mechanical brake (24) and the worm and gear redundancy device braking function of the left rear corner module and the right rear corner module both fail, the vehicle control unit VCU (7) controls the mechanical brake of the remaining healthy corner module itself or realizes braking by engaging the first electromagnetic clutch and the third electromagnetic clutch and using the worm drive motor power to realize braking, and executes two-wheel braking mode.

9. The control method of the worm-gear dual-function redundant based angular module drive-by-wire chassis system according to claim 6, characterized in that, In the step S2, if the vehicle control unit VCU (7) detects an emergency braking signal or if the left front corner module and the right rear corner module lose steering ability at the same time, or the right front corner module and the left rear corner module lose steering ability, the emergency braking mode is switched to; the vehicle control unit VCU (7) controls the healthy mechanical brake (24) of all corner modules to output the maximum braking force, and for the corner module whose mechanical brake is not healthy, if its worm and gear redundancy device braking function is healthy, the worm drive motor power is introduced by engaging the first electromagnetic clutch and the third electromagnetic clutch to provide the maximum redundant braking force.

10. A control method of a worm-worm screw dual-function redundant based angular module drive-by-wire chassis system according to claim 6, 7, 8 or 9, characterized in that, When the vehicle control unit VCU (7) switches to the redundancy mode, the degradation mode or the emergency braking mode, a warning information is sent to the vehicle operation panel and an intelligent voice broadcast is performed.

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