Vehicle redundancy steer-by-wire and auxiliary driving integrated system and control method thereof

Abstract

The invention provides a vehicle redundant steer-by-wire and auxiliary driving integrated system and a control method thereof. The vehicle redundant steer-by-wire and auxiliary driving integrated system comprises a steering mechanism, a driving mechanism, a steer-by-wire motor, an auxiliary motor, a first electromagnetic clutch, a second electromagnetic clutch, an energy storage mechanism, a VCU, a detection mechanism and a steering shaft. The VCU is connected with the steer-by-wire motor, the auxiliary motor, the driving motor, the first electromagnetic clutch, the second electromagnetic clutch and the detection mechanism, monitors the running state of the steer-by-wire motor and the driving torque requirement Tr in real time, and controls connection or disconnection of the first electromagnetic clutch and the second electromagnetic clutch to achieve switching of working modes. The drive-by-wire steering system and the drive-by-wire steering system are integrated, the coupling mode switching of the auxiliary motor and the electromagnetic clutch is utilized, the safety problem of a traditional drive-by-wire steering system when the drive-by-wire steering motor breaks down is solved, safer and more efficient vehicle steering and driving can be achieved, and meanwhile the energy utilization efficiency of the vehicle under different working conditions is improved.

Description

Technical Field

[0001] The present invention belongs to the field of redundant wire-controlled steering and auxiliary drive integrated systems, and in particular to a vehicle redundant wire-controlled steering and auxiliary drive integrated system and a control method thereof. Background Art

[0002] Traditional automotive steering systems usually use mechanical hydraulic power or full electronic power to achieve steering. However, with the development of electric and hybrid vehicles, the requirements for vehicle energy efficiency and safety are becoming increasingly higher. Although traditional wire-controlled steering systems can achieve precise steering control, when the wire-controlled steering motor fails, it may cause the vehicle to lose steering ability, thereby endangering driving safety.

[0003] In addition, with the advancement of electric vehicle technology, how to improve energy efficiency while ensuring vehicle power performance has become an important issue. During the braking and coasting process of the vehicle, the energy recovery system can convert braking energy into electrical energy for storage, which can effectively increase the vehicle's range. However, the existing energy recovery system still has some limitations in practical applications, such as low energy recovery efficiency and high system complexity. Summary of the invention

[0004] In view of the above technical problems, the present invention provides an integrated system of redundant wire-controlled steering and auxiliary drive for a vehicle and a control method thereof.

[0005] The present invention solves the safety problem of the traditional steer-by-wire system when the steer-by-wire motor fails by using the integrated system of redundant steer-by-wire and auxiliary drive of the vehicle and the coupling mode switching of the auxiliary motor and the electromagnetic clutch, and improves the energy utilization efficiency under different driving conditions by optimizing the working modes of the drive motor and the auxiliary motor. In addition, the system can also realize braking and sliding energy recovery through the auxiliary motor, further improving the comprehensive utilization efficiency of energy.

[0006] Note that the description of these objectives does not prevent the existence of other objectives. One embodiment of the present invention does not need to achieve all of the above objectives. Objectives other than the above objectives can be extracted from the description of the specification, drawings, and claims.

[0007] The present invention achieves the above technical objectives through the following technical means.

[0008] An integrated system of redundant wire-controlled steering and auxiliary drive for a vehicle, comprising a steering mechanism, a drive mechanism, a wire-controlled steering motor, an auxiliary motor, a first electromagnetic clutch, a second electromagnetic clutch, an energy storage mechanism, a VCU, a detection mechanism and a steering shaft;

[0009] The wire-controlled steering motor is connected to the steering mechanism via a first steering reducer to rotate the wheels;

[0010] The driving mechanism includes a driving motor, a main transmission shaft and a half shaft, wherein the driving motor is connected to the input end of the main transmission shaft, the output end of the main transmission shaft is connected to the half shaft, and the two ends of the half shaft are respectively connected to the wheel hubs of the wheels on both sides; the auxiliary motor is connected to the steering mechanism through the second steering reducer, the first electromagnetic clutch is installed between the auxiliary motor and the second steering reducer, and the first electromagnetic clutch is used to control the coupling of the auxiliary motor and the steering mechanism; the auxiliary motor is connected to the main transmission shaft through the planetary gear mechanism, the second electromagnetic clutch is installed between the auxiliary motor and the planetary gear mechanism, and the second electromagnetic clutch is used to control the coupling of the auxiliary motor and the driving motor;

[0011] The energy storage mechanism is connected to the auxiliary motor and the drive motor respectively;

[0012] The detection mechanism is connected to the output end of the steering shaft, and is used to collect the angle signal and the torque signal, and transmit them to the VCU, and the input end of the steering shaft is connected to the steering wheel;

[0013] The VCU is respectively connected to the wire-controlled steering motor, the auxiliary motor, the drive motor, the first electromagnetic clutch, the second electromagnetic clutch and the detection mechanism. The VCU monitors the operating status of the wire-controlled steering motor and the driving torque demand Tr in real time, controls the connection or disconnection of the first electromagnetic clutch and the second electromagnetic clutch, and realizes the switching of the working mode.

[0014] In the above scheme, the working modes include redundant safety steering mode, auxiliary driving mode and energy recovery mode;

[0015] The VCU monitors the driving torque demand Tr and the self-test data of the wire-controlled steering motor in real time and processes the data; the VCU determines whether the wire-controlled steering motor fails;

[0016] If the wire-controlled steering motor fails, the redundant safety steering mode is executed, the VCU controls the first electromagnetic clutch to be connected, the second electromagnetic clutch to be disconnected, and the auxiliary motor to execute the electric mode to provide steering assistance;

[0017] If the steer-by-wire motor does not fail, a preliminary determination of the driving torque demand Tr is performed. If Tr>0, an auxiliary driving mode is executed; if Tr≤0, an energy recovery mode is executed;

[0018] If the auxiliary drive mode is executed, the driving torque demand Tr is determined again. If Tr≤Ta, the uniform speed drive mode is executed, the VCU controls the first electromagnetic clutch to be disconnected, the second electromagnetic clutch to be disconnected, the VCU controls the auxiliary motor to stop working, and the drive motor provides the driving torque alone; if Tr>Ta, the acceleration drive mode is executed, the VCU controls the first electromagnetic clutch to be disconnected, the second electromagnetic clutch to be connected, the auxiliary motor executes the auxiliary drive mode, and the drive motor and the auxiliary motor cooperate to provide the driving torque;

[0019] If the energy recovery mode is executed, the VCU controls the first electromagnetic clutch to disconnect and the second electromagnetic clutch to connect, and the VCU controls the auxiliary motor to reverse and provide reverse torque to achieve power generation; the VCU controls the drive motor to stop working.

[0020] In the above scheme, the driving mechanism also includes a main reducer and a differential; the output end of the main drive shaft is connected to the input end of the differential for transmitting the driving torque, and the output end of the differential is connected to the half-shaft; the main reducer is connected to the main drive shaft.

[0021] In the above scheme, the steering mechanism includes a trapezoidal arm, a steering tie rod, a first rack and pinion mechanism and a second rack and pinion mechanism;

[0022] Both ends of the steering tie rod are connected to trapezoidal arms respectively, and the trapezoidal arms are connected to the half shafts through steering knuckles respectively;

[0023] The wire-controlled steering motor is connected to the input end of the first gear rack mechanism through the first steering reducer, and the output end of the first gear rack mechanism is connected to the steering tie rod, so as to transmit the torque of the wire-controlled steering motor to the steering tie rod to rotate the wheel;

[0024] The auxiliary motor is connected to the input end of the second gear rack mechanism through the second steering reducer, and the output end of the second gear rack mechanism is connected to the steering tie rod, so as to transmit the torque of the auxiliary motor to the steering tie rod to rotate the wheel.

[0025] In the above solution, the sun gear of the planetary gear mechanism is connected to the auxiliary motor to fix the planet carrier, and the outer ring gear of the planetary gear mechanism is connected to the main transmission shaft through gear meshing.

[0026] In the above scheme, the energy storage mechanism includes an inverter and a power supply; the inverter is placed between the auxiliary motor and the power supply, and the inverter is used to convert the AC power generated during energy recovery into DC power and store it in the power supply. The inverter is also connected to the drive motor to convert the DC power of the power supply into AC power for the drive motor when needed.

[0027] A control method for the integrated system of redundant vehicle steer-by-wire and auxiliary drive comprises the following steps:

[0028] The VCU monitors the operating state of the wire-controlled steering motor and the driving torque demand Tr in real time;

[0029] The VCU switches between the redundant safety steering mode, the auxiliary driving mode and the energy recovery mode by controlling the connection or disconnection of the first electromagnetic clutch and the second electromagnetic clutch according to whether the wire-controlled steering motor fails and the driving torque demand Tr.

[0030] In the above scheme, the redundant safety steering mode includes the following steps:

[0031] If the VCU determines that the wire-controlled steering motor fails, the redundant safety steering mode is executed; the VCU controls the first electromagnetic clutch to be connected, the second electromagnetic clutch to be disconnected, and the auxiliary motor to execute the electric mode to provide steering assistance.

[0032] In the above scheme, the auxiliary driving mode includes the following steps:

[0033] If the VCU determines that the wire-controlled steering motor has not failed, a preliminary determination of the driving torque demand Tr is performed. If Tr>0, the auxiliary driving mode is executed, and the driving torque demand Tr is determined again. If Tr≤Ta, a uniform speed driving mode is executed, and the VCU controls the first electromagnetic clutch to disconnect and the second electromagnetic clutch to disconnect. The VCU controls the auxiliary motor to stop working, and the drive motor provides the driving torque alone. If Tr>Ta, an acceleration driving mode is executed, and the VCU controls the first electromagnetic clutch to disconnect and the second electromagnetic clutch to connect. The auxiliary motor executes the auxiliary driving mode, and the drive motor and the auxiliary motor cooperate to provide the driving torque.

[0034] In the above scheme, the energy recovery mode includes the following steps:

[0035] If Tr≤0, the energy recovery mode is executed; if the energy recovery mode is executed, the VCU controls the first electromagnetic clutch to disconnect and the second electromagnetic clutch to connect, and the VCU controls the auxiliary motor to reverse and provide reverse torque to achieve power generation; the VCU controls the drive motor to stop working.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention integrates a wire-controlled steering and drive system, and utilizes the coupling mode switching of the auxiliary motor and the electromagnetic clutch to solve the safety problem of the traditional wire-controlled steering system when the wire-controlled steering motor fails, and at the same time improves the energy utilization efficiency of the vehicle under different working conditions. When the wire-controlled steering motor of the present invention fails, the system can automatically switch to a redundant mode, and provide steering assistance through the auxiliary motor to ensure that the vehicle still has reliable steering capabilities. In addition, under different driving conditions, the system can optimize the working mode of the auxiliary motor according to actual needs. When additional torque or acceleration is required, the auxiliary motor and the drive motor work together to increase the driving torque; when driving at a constant speed or low torque demand, the auxiliary motor quits work to save energy. During vehicle braking or sliding, the system can realize braking energy recovery through the auxiliary motor, convert braking energy into electrical energy and store it, and further improve the comprehensive utilization rate of energy. The present invention can achieve safer and more efficient vehicle steering and driving, and is suitable for the application needs of modern electric vehicles.

[0038] Note that the description of these effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above can be clearly seen and extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a top view of an integrated system structure of redundant wire-controlled steering and auxiliary drive for a vehicle according to an embodiment of the present invention;

[0040] Figure 2 It is a front view of the integrated system structure of redundant wire-controlled steering and auxiliary drive for a vehicle according to one embodiment of the present invention;

[0041] Figure 3 The invention discloses a control architecture of an integrated system control method for redundant steer-by-wire and auxiliary drive of a vehicle according to an embodiment of the present invention.

[0042] In the figure, 1. wheel; 2. wheel hub; 3. trapezoidal arm; 4. steering tie rod; 5. first electromagnetic clutch; 6. auxiliary motor; 7. second electromagnetic clutch; 8. planetary gear mechanism; 9. inverter; 10. power supply; 11. drive motor; 12. VCU; 13. detection mechanism; 14. steering shaft; 15. steering wheel; 16. main drive shaft; 17. main reducer; 18. wire-controlled steering motor; 19. first steering reducer; 20. half shaft; 21. first rack-and-pinion mechanism; 22. differential; 23. second rack-and-pinion mechanism; 24. second steering reducer; 25. steering knuckle. DETAILED DESCRIPTION

[0043] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, 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" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Figure 1 and 2 The figure shows a preferred embodiment of the integrated system of redundant wire-controlled steering and auxiliary drive for a vehicle of the invention, wherein the integrated system of redundant wire-controlled steering and auxiliary drive for a vehicle comprises a steering mechanism, a drive mechanism, a wire-controlled steering motor 18, an auxiliary motor 6, a first electromagnetic clutch 5, a second electromagnetic clutch 7, an energy storage mechanism, a VCU 12, a detection mechanism 13 and a steering shaft 14;

[0047] The wire-controlled steering motor 18 is connected to the steering mechanism via a first steering reducer 19 and is used to rotate the wheel 1;

[0048] The driving mechanism includes a driving motor 11, a main transmission shaft 16 and a half shaft 20, wherein the driving motor 11 is connected to the input end of the main transmission shaft 16, the output end of the main transmission shaft 16 is connected to the half shaft 20, and the two ends of the half shaft 20 are respectively connected to the wheel hubs 2 of the wheels 1 on both sides;

[0049] The auxiliary motor 6 is connected to the steering mechanism through the second steering reducer 24, and the first electromagnetic clutch 5 is installed between the auxiliary motor 6 and the second steering reducer 24. The first electromagnetic clutch 5 is used to control the coupling of the auxiliary motor 6 and the steering mechanism; the auxiliary motor 6 is connected to the main transmission shaft 16 through the planetary gear mechanism 8, and the torque is adjusted by the planetary gear mechanism 8, so that the auxiliary motor 6 and the drive motor 11 can cooperate to provide the driving torque under the required working conditions. The second electromagnetic clutch 7 is installed between the auxiliary motor 6 and the planetary gear mechanism 8, and the second electromagnetic clutch 7 is used to control the coupling of the auxiliary motor 6 and the drive motor 11;

[0050] The energy storage mechanism is connected to the auxiliary motor 6 and the drive motor 11 respectively;

[0051] The detection mechanism 13 is connected to the output end of the steering shaft 14 to collect the angle signal and the torque signal and transmit them to the VCU 12. The input end of the steering shaft 14 is connected to the steering wheel 15.

[0052] The VCU12 is respectively connected to the wire-controlled steering motor 18, the auxiliary motor 6, the drive motor 11, the first electromagnetic clutch 5, the second electromagnetic clutch 7 and the detection mechanism 13. The VCU12 monitors the operating status of the wire-controlled steering motor 18 and the driving torque demand Tr in real time, and controls the connection or disconnection of the first electromagnetic clutch 5 and the second electromagnetic clutch 7 to achieve switching of the working mode.

[0053] The working modes include redundant safety steering mode, auxiliary driving mode and energy recovery mode;

[0054] The VCU 12 monitors the driving torque demand Tr and the self-test data of the wire-controlled steering motor 18 in real time and processes the data; the VCU 12 determines whether the wire-controlled steering motor 18 is faulty;

[0055] If the wire-controlled steering motor 18 fails, the redundant safety steering mode is executed, the VCU 12 controls the first electromagnetic clutch 5 to be connected, the second electromagnetic clutch 7 to be disconnected, and the auxiliary motor 6 to execute the electric mode to provide steering assistance;

[0056] If the steer-by-wire motor 18 is not faulty, a preliminary determination of the driving torque demand Tr is performed. If Tr>0, the auxiliary driving mode is executed; if Tr≤0, the energy recovery mode is executed;

[0057] If the auxiliary drive mode is executed, the drive torque demand Tr is determined again. If Tr≤Ta, the uniform speed drive mode is executed, the VCU12 controls the first electromagnetic clutch 5 to be disconnected, the second electromagnetic clutch 7 to be disconnected, the VCU12 controls the auxiliary motor 6 to stop working, and the drive motor 11 provides the drive torque alone; if Tr>Ta, the acceleration drive mode is executed, the VCU12 controls the first electromagnetic clutch 5 to be disconnected, the second electromagnetic clutch 7 to be connected, the auxiliary motor 6 executes the auxiliary drive mode, and the drive motor 11 and the auxiliary motor 6 cooperate to provide the drive torque;

[0058] If the energy recovery mode is executed, the VCU12 controls the first electromagnetic clutch 5 to be disconnected and the second electromagnetic clutch 7 to be connected. The VCU12 controls the auxiliary motor 6 to reverse and provide reverse torque to achieve power generation. The VCU12 controls the drive motor 11 to stop working.

[0059] The steering mechanism includes a trapezoidal arm 3, a steering tie rod 4, a first gear rack mechanism 21 and a second gear rack mechanism 23; the two ends of the steering tie rod 4 are respectively connected to the trapezoidal arms 3, and the trapezoidal arms 3 are respectively connected to the half shaft 20 through the steering knuckle 25; the wire-controlled steering motor 18 is connected to the input end of the first gear rack mechanism 21 through the first steering reducer 19, and the output end of the first gear rack mechanism 21 is connected to the steering tie rod 4, so as to transmit the torque of the wire-controlled steering motor 18 to the steering tie rod 4 for rotating the wheel 1; the auxiliary motor 6 is connected to the input end of the second gear rack mechanism 23 through the second steering reducer 24, and the output end of the second gear rack mechanism 23 is connected to the steering tie rod 4, so as to transmit the torque of the auxiliary motor 6 to the steering tie rod 4 for rotating the wheel 1.

[0060] The system of the present invention relies on multiple key components to work together to achieve redundant wire-controlled steering and auxiliary drive integrated control.

[0061] The wheel 1 is the final execution component of the system, which realizes the steering and driving of the vehicle after receiving the steering and driving torque. The wheel hub 2 provides the installation and transmission basis for steering and driving. The trapezoidal arm 3, the steering knuckle 25 and the steering tie rod 4, these mechanical structural components are used to transmit the torque generated by the steering to the wheel 1. One end of the trapezoidal arm 3 is connected to the steering knuckle 25, and the other end is connected to the trapezoidal arm 3 on the other side of the vehicle through the steering tie rod 4, ensuring that the steering torque can be smoothly transmitted to the wheels 1 on both sides.

[0062] The wire-controlled steering motor 18 is one of the core components of the system and is responsible for outputting the steering torque under normal circumstances. The wire-controlled steering motor 18 transmits the torque to the steering tie rod 4 through the first steering reducer 19 and the first rack-and-pinion mechanism 21, and finally rotates the wheel 1.

[0063] The auxiliary motor 6 takes over the steering work when the wire-controlled steering motor 18 fails, and under certain working conditions, it cooperates with the drive motor 11 to provide driving torque for the vehicle. In addition, the auxiliary motor 6 also has the function of energy recovery, converting kinetic energy into electrical energy during coasting or braking.

[0064] The first electromagnetic clutch 5 and the second electromagnetic clutch 7 are respectively used to couple the auxiliary motor 6 with the steering mechanism or the drive mechanism to ensure that the system can dynamically switch between different modes. Specifically, the first electromagnetic clutch 5 is used to control the coupling of the auxiliary motor 6 with the steering mechanism, and the second electromagnetic clutch 7 is used to control the coupling of the auxiliary motor 6 with the drive mechanism.

[0065] Preferably, the planetary gear mechanism 8 includes: a sun gear, planetary gears, a planetary carrier, and an outer ring gear. The sun gear is connected to the auxiliary motor 6 to fix the planetary carrier. The outer ring gear is connected to the main transmission shaft 16 through gear meshing. In this way, the output speed and driving torque can be flexibly adjusted.

[0066] The VCU 12 is the central control unit of the entire system, responsible for real-time monitoring of the vehicle status and performing coordinated control of each subsystem. The VCU 12 switches between different working modes by controlling the connection or disconnection of the electromagnetic clutch.

[0067] The inverter 9 converts the AC power generated during energy recovery into DC power and stores it in the power supply 10. Conversely, when needed, the inverter 9 converts the DC power into AC power for the drive motor 11 to ensure efficient and stable power management of the system.

[0068] The rotor of the driving motor 11 is connected to the input end of the main transmission shaft 16 to provide the main driving torque.

[0069] The driving mechanism also includes a main reducer 17 and a differential 22; the output end of the main transmission shaft 16 is connected to the input end of the differential 22 for transmitting the driving torque, and the output end of the differential 22 is connected to the half shaft 20; the main reducer 17 is connected to the main transmission shaft 16, and is mainly responsible for reducing the rotation speed and increasing the driving torque. The differential 22 allows the wheel 1 to rotate at different speeds when turning, and at the same time reasonably distributes the driving torque to the wheel 1 to improve the maneuverability and stability of the vehicle.

[0070] The sun gear of the planetary gear mechanism 8 is connected to the auxiliary motor 6 to fix the planet carrier, and the outer ring gear of the planetary gear mechanism 8 is connected to the main transmission shaft 16 through gear meshing.

[0071] The energy storage mechanism includes an inverter 9 and a power supply 10; the inverter 9 is placed between the auxiliary motor 6 and the power supply 10, and the inverter 9 is used to convert the AC power generated during energy recovery into DC power and store it in the power supply 10. The inverter 9 is also connected to the drive motor 11, and is used to convert the DC power of the power supply 10 into AC power for the drive motor 11 when needed, which is conducive to ensuring efficient and stable power management of the system, 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.

[0072] The detection mechanism (13) comprises a rotation angle sensor and a torque sensor, wherein the rotation angle sensor is used to detect the rotation angle signal of the steering shaft, and the torque sensor is used to detect the torque signal of the steering shaft.

[0073] The present invention also provides a control method for an integrated system of redundant vehicle steering by wire and auxiliary drive, which can switch multiple working modes according to the failure conditions of electronic components and the driving torque requirements. The working modes and switching principles are as follows:

[0074] (I) The control method of the integrated system of redundant vehicle steering by wire and auxiliary drive described in the present invention includes an overall system control architecture based on control mode switching.

[0075] The overall content of the overall system control architecture based on control mode switching is as follows:

[0076] like Figure 3 As shown, the control method of the integrated system of redundant vehicle wire-controlled steering and auxiliary drive described in the present invention covers a redundant safety steering mode, an auxiliary drive mode and an energy recovery mode in the overall mode switching control architecture.

[0077] The integrated system of redundant vehicle steering by wire and auxiliary drive is centrally controlled by VCU12, which monitors the operating status of each subsystem in real time, such as whether the steering by wire motor 18 is faulty, the driving torque demand Tr, etc., and selects a suitable operating mode according to different working conditions.

[0078] When the steer-by-wire motor 18 fails, the VCU 12 prioritizes safety and immediately switches to the redundant safety steering mode to ensure that the vehicle can continue to perform the steering function.

[0079] Under normal steering conditions, that is, when the wire control steering motor 18 is fault-free, the VCU 12 determines the auxiliary driving mode or the energy recovery mode according to the actual driving state of the vehicle. After the auxiliary driving mode or the energy recovery mode is determined, the state switching of the electromagnetic clutch connection and disconnection is used, and at the same time, according to the driving torque demand or acceleration state of the vehicle, the dynamic switching between the uniform speed driving mode, the acceleration driving mode, the sliding energy recovery mode, and the braking energy recovery mode is realized.

[0080] Specifically, the control method of the integrated system of redundant vehicle steering by wire and auxiliary drive comprises the following steps:

[0081] The VCU 12 monitors the operating state and driving torque demand Tr of the wire-controlled steering motor 18 in real time. The VCU 12 collects self-test data of the wire-controlled steering motor 18 and processes the data according to the driving torque demand Tr calculated by the VCU 12;

[0082] The VCU 12 switches between the redundant safety steering mode, the auxiliary driving mode and the energy recovery mode by controlling the connection or disconnection of the first electromagnetic clutch 5 and the second electromagnetic clutch 7 according to whether the wire-controlled steering motor 18 fails and the driving torque demand Tr.

[0083] (II) The control method of the integrated system of redundant vehicle wire-controlled steering and auxiliary drive of the present invention includes a redundant safety steering mode. The redundant safety steering mode includes the following steps:

[0084] If the VCU 12 determines that the wire-controlled steering motor 18 fails, the redundant safety steering mode is executed; the VCU 12 controls the first electromagnetic clutch 5 to be connected, the second electromagnetic clutch 7 to be disconnected, and the auxiliary motor 6 to execute the electric mode to provide steering assistance.

[0085] Specifically, when the VCU 12 detects that the wire-controlled steering motor 18 fails, the system automatically enters the redundant safety steering mode. In the redundant safety steering mode, the system's working process is as follows:

[0086] (1) VCU 12 detects a steer-by-wire fault: VCU 12 monitors the working status of the steer-by-wire motor 18 in real time. Once the motor is found to be working abnormally or failing, VCU 12 immediately activates the redundant safety steering mode.

[0087] (2) Electromagnetic clutch switching: VCU 12 controls the first electromagnetic clutch 5 to connect, coupling the auxiliary motor 6 with the second steering reducer 24. At the same time, the second electromagnetic clutch 7 is disconnected to ensure that the auxiliary motor 6 is only used for steering and does not participate in driving.

[0088] (3) The auxiliary motor 6 provides steering assistance: In the redundant safety steering mode, the auxiliary motor 6 transmits the steering torque through the second steering reducer 24 and the second rack and pinion mechanism 23, replacing the failed wire-controlled steering motor 18, ensuring that the vehicle can still steer normally in an emergency.

[0089] (4) Steering torque transmission: The steering torque generated by the auxiliary motor 6 is transmitted to the steering tie rod 4 through the second gear rack mechanism 23, and then transmitted to the wheel 1 through the trapezoidal arm 3 and the steering knuckle 25, thereby realizing the rotation of the wheel 1.

[0090] (III) The control method of the integrated system of redundant steer-by-wire and auxiliary drive of the vehicle of the present invention includes an auxiliary drive mode, and when the steer-by-wire motor 18 is working normally without fault, the system determines the auxiliary drive mode and the energy recovery mode. When the steer-by-wire motor 18 is not faulty and the vehicle drive torque demand is greater than or equal to 0, it is determined that the vehicle is in the auxiliary drive mode.

[0091] The auxiliary driving mode includes the following steps:

[0092] If the VCU12 determines that the wire-controlled steering motor 18 has not failed, a preliminary determination of the driving torque demand Tr is performed. If Tr>0, the auxiliary driving mode is executed, and the driving torque demand Tr is determined again. If Tr≤Ta, a uniform speed driving mode is executed, and the VCU12 controls the first electromagnetic clutch 5 to disconnect, the second electromagnetic clutch 7 to disconnect, the VCU12 controls the auxiliary motor 6 to stop working, and the drive motor 11 provides the driving torque alone; if Tr>Ta, an acceleration driving mode is executed, and the VCU12 controls the first electromagnetic clutch 5 to disconnect, the second electromagnetic clutch 7 to connect, the auxiliary motor 6 executes the auxiliary driving mode, and the drive motor 11 and the auxiliary motor 6 cooperate to provide the driving torque.

[0093] Specifically, in the auxiliary drive mode, the main task of the auxiliary motor 6 in this mode is to cooperate with the drive motor 11 to provide additional driving torque, especially when the vehicle requires high torque or acceleration. The detailed working process of the auxiliary drive mode is as follows:

[0094] (1) VCU12 preliminarily determines the driving torque demand: If VCU12 detects that the steer-by-wire motor 18 is not faulty, it preliminarily determines the driving torque demand Tr. If Tr>0, the auxiliary driving mode is executed.

[0095] (2) VCU 12 determines the driving torque demand again: VCU 12 determines whether the auxiliary motor 6 is required to participate in the driving according to the driving torque demand Tr of the vehicle and the maximum output torque Ta of the driving motor 11 .

[0096] (3) Uniform speed driving mode:

[0097] When Tr≤Ta, the drive motor 11 can independently meet the driving force demand of the vehicle, the system enters the uniform speed drive mode, the first electromagnetic clutch 5 and the second electromagnetic clutch 7 are disconnected, the auxiliary motor 6 does not work, and the drive motor 11 provides driving torque independently through the main drive shaft 16 and the differential 22 to drive the vehicle forward.

[0098] (4) Acceleration drive mode:

[0099] When Tr>Ta, the drive motor 11 cannot provide sufficient driving force alone, and the system enters the acceleration drive mode. VCU12 controls the second electromagnetic clutch 7 to connect, and the auxiliary motor 6 is coupled with the planetary gear mechanism 8. The torque is adjusted by the planetary gear mechanism 8. The auxiliary motor 6 and the drive motor 11 jointly provide driving torque to meet high torque demand conditions such as vehicle starting or rapid acceleration.

[0100] (5) Driving torque transmission: In the acceleration driving mode, the auxiliary motor 6 works together with the driving motor 11 to transmit the driving force to the differential 22 through the main transmission shaft 16, and then the differential 22 reasonably distributes the driving force to the half-axles 20, and finally drives the wheel 1 to rotate through the wheel hub 2.

[0101] (IV) The control method of the integrated system of redundant vehicle wire steering and auxiliary drive of the present invention includes an energy recovery mode. When the wire steering motor 18 is working normally without fault, the system determines the auxiliary drive mode and the energy recovery mode. When the wire steering motor 18 is not faulty and the vehicle drive torque demand is less than or equal to 0, it is determined that the vehicle is in the energy recovery mode.

[0102] The energy recovery mode includes the following steps:

[0103] If Tr≤0, the energy recovery mode is executed; if the energy recovery mode is executed, the VCU12 controls the first electromagnetic clutch 5 to disconnect and the second electromagnetic clutch 7 to connect, and the VCU12 controls the auxiliary motor 6 to reverse and provide reverse torque to achieve power generation; the VCU12 controls the drive motor 11 to stop working.

[0104] Specifically, in the energy recovery mode, the auxiliary motor 6 recovers energy when the vehicle is coasting or braking, converting kinetic energy into electrical energy and storing it in the power supply 10. The working process of the energy recovery mode is as follows:

[0105] When the vehicle is in a coasting state (i.e. the driver releases the accelerator pedal but does not step on the brake pedal), the driving torque demand Tr≤0, and the system automatically enters the coasting energy recovery mode.

[0106] (1) VCU12 determines the driving torque demand: VCU12 monitors the driving torque demand of the vehicle in real time. When it detects that Tr≤0 and there is no braking signal, it determines that the vehicle is in a coasting state.

[0107] (2) Electromagnetic clutch control:

[0108] VCU12 controls the first electromagnetic clutch 5 to disconnect, ensuring that the auxiliary motor 6 is separated from the steering system and does not affect the steering operation. At the same time, the second electromagnetic clutch 7 is connected to ensure that the auxiliary motor 6 is coupled with the planetary gear mechanism 8, and the drive motor 11 stops working to avoid the output of driving torque.

[0109] (3) Auxiliary motor 6 generates electricity in reverse: During the coasting process, the auxiliary motor 6 runs in reverse through the planetary gear mechanism 8, and generates electricity by using the inertia of the vehicle. The kinetic energy of the wheels is transmitted to the auxiliary motor 6 through the transmission system, and the auxiliary motor 6 converts the kinetic energy into electrical energy.

[0110] (4) Power storage: The generated power is converted into direct current through the inverter 9 and stored in the vehicle's power supply 10 system for later use.

[0111] (5) System recovery: After coasting ends, if the vehicle needs driving force again (for example, the driver presses the accelerator pedal), the system automatically exits the coasting energy recovery mode, the auxiliary motor 6 stops generating electricity, and the drive motor 11 resumes the normal working mode.

[0112] When the vehicle is in braking state (i.e. the driver presses the brake pedal), the system enters the braking energy recovery mode.

[0113] (1) VCU12 determines the braking state: When VCU12 detects that the driving torque demand Tr ≤ 0 and there is a braking signal, it determines that the vehicle is in a braking state. The system automatically switches to the braking energy recovery mode.

[0114] (2) Electromagnetic clutch control:

[0115] VCU12 controls the first electromagnetic clutch 5 to disconnect, ensuring that the auxiliary motor 6 is separated from the steering system, and the second electromagnetic clutch 7 remains connected, ensuring that the auxiliary motor 6 is coupled to the planetary gear mechanism 8. The drive motor 11 stops working in this state.

[0116] (3) Auxiliary motor 6 generates electricity in reverse: During braking, the deceleration of the vehicle causes the kinetic energy of the wheels to be transmitted to the auxiliary motor 6 through the transmission system. The auxiliary motor 6 generates electricity in reverse under the control of the VCU 12, converting the kinetic energy into electrical energy.

[0117] (4) Energy storage: The energy generated by the auxiliary motor 6 is converted into direct current through the inverter 9 and stored in the power supply system 10. This process effectively recovers the braking energy and reduces the mechanical energy loss of the brake system.

[0118] (5) After braking: When the vehicle stops braking or needs to re-accelerate, the VCU 12 control system exits the braking energy recovery mode, the auxiliary motor 6 stops generating electricity, and the drive motor 11 resumes the normal driving mode.

[0119] The present invention integrates a wire-controlled steering and drive system and utilizes coupling mode switching between an auxiliary motor and an electromagnetic clutch, thereby solving the safety problem of a traditional wire-controlled steering system when a wire-controlled steering motor fails, enabling safer and more efficient vehicle steering and driving, while improving the energy efficiency of the vehicle under different operating conditions.

[0120] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0121] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An integrated system of redundant vehicle steer-by-wire and auxiliary drive, characterized in that: It comprises a steering mechanism, a driving mechanism, a wire-controlled steering motor (18), an auxiliary motor (6), a first electromagnetic clutch (5), a second electromagnetic clutch (7), an energy storage mechanism, a VCU (12), a detection mechanism (13) and a steering shaft (14); The wire-controlled steering motor (18) is connected to the steering mechanism via a first steering reducer (19) and is used to rotate the wheel (1); The driving mechanism comprises a driving motor (11), a main transmission shaft (16) and a half shaft (20); the driving motor (11) is connected to an input end of the main transmission shaft (16); the output end of the main transmission shaft (16) is connected to the half shaft (20); and both ends of the half shaft (20) are respectively connected to wheel hubs (2) of wheels (1) on both sides; The auxiliary motor (6) is connected to the steering mechanism via a second steering reducer (24); a first electromagnetic clutch (5) is installed between the auxiliary motor (6) and the second steering reducer (24); the first electromagnetic clutch (5) is used to control the coupling between the auxiliary motor (6) and the steering mechanism; the auxiliary motor (6) is connected to the main transmission shaft (16) via a planetary gear mechanism (8); a second electromagnetic clutch (7) is installed between the auxiliary motor (6) and the planetary gear mechanism (8); the second electromagnetic clutch (7) is used to control the coupling between the auxiliary motor (6) and the drive motor (11); The energy storage mechanism is connected to the auxiliary motor (6) and the drive motor (11) respectively; The detection mechanism (13) is connected to the output end of the steering shaft (14) and is used to collect the rotation angle signal and the torque signal and transmit them to the VCU (12); the input end of the steering shaft (14) is connected to the steering wheel (15); The VCU (12) is respectively connected to the wire-controlled steering motor (18), the auxiliary motor (6), the drive motor (11), the first electromagnetic clutch (5), the second electromagnetic clutch (7) and the detection mechanism (13); the VCU (12) monitors the operating state of the wire-controlled steering motor (18) and the driving torque demand Tr in real time, controls the connection or disconnection of the first electromagnetic clutch (5) and the second electromagnetic clutch (7), and realizes the switching of the working mode.

2. The integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 1, characterized in that: The working modes include redundant safety steering mode, auxiliary driving mode and energy recovery mode; The VCU (12) monitors the driving torque demand Tr and the self-test data of the wire-controlled steering motor (18) in real time, and processes the data; the VCU (12) determines whether the wire-controlled steering motor (18) has a fault; If the wire-controlled steering motor (18) fails, a redundant safety steering mode is executed, the VCU (12) controls the first electromagnetic clutch (5) to be connected, the second electromagnetic clutch (7) to be disconnected, and the auxiliary motor (6) to execute an electric mode to provide steering assistance; If the wire-controlled steering motor (18) does not fail, a preliminary determination of the driving torque demand Tr is performed, and if Tr>0, an auxiliary driving mode is executed; if Tr≤0, an energy recovery mode is executed; If the auxiliary drive mode is executed, the drive torque demand Tr is determined again. If Tr≤Ta, the uniform speed drive mode is executed, the VCU (12) controls the first electromagnetic clutch (5) to be disconnected, the second electromagnetic clutch (7) to be disconnected, the VCU (12) controls the auxiliary motor (6) to stop working, and the drive motor (11) provides the drive torque alone. If Tr>Ta, the acceleration drive mode is executed, the VCU (12) controls the first electromagnetic clutch (5) to be disconnected, the second electromagnetic clutch (7) to be connected, the auxiliary motor (6) executes the auxiliary drive mode, and the drive motor (11) and the auxiliary motor (6) cooperate to provide the drive torque. If the energy recovery mode is executed, the VCU (12) controls the first electromagnetic clutch (5) to be disconnected and the second electromagnetic clutch (7) to be connected; the VCU (12) controls the auxiliary motor (6) to be reversed to provide reverse torque to achieve power generation; and the VCU (12) controls the drive motor (11) to stop working.

3. The integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 1, characterized in that: The driving mechanism further comprises a main reducer (17) and a differential (22); The output end of the main transmission shaft (16) is connected to the input end of the differential (22) for transmitting driving torque, and the output end of the differential (22) is connected to the half shaft (20); The main reducer (17) is connected to the main transmission shaft (16).

4. The integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 1, characterized in that: The steering mechanism comprises a trapezoidal arm (3), a steering tie rod (4), a first rack and pinion mechanism (21) and a second rack and pinion mechanism (23); The two ends of the steering tie rod (4) are respectively connected to a trapezoidal arm (3), and the trapezoidal arm (3) is respectively connected to the half shaft (20) through a steering knuckle (25); The wire-controlled steering motor (18) is connected to the input end of the first gear rack mechanism (21) via the first steering reducer (19), and the output end of the first gear rack mechanism (21) is connected to the steering tie rod (4), so as to transmit the torque of the wire-controlled steering motor (18) to the steering tie rod (4) to rotate the wheel (1); The auxiliary motor (6) is connected to the input end of the second gear rack mechanism (23) via the second steering reducer (24); the output end of the second gear rack mechanism (23) is connected to the steering tie rod (4), and the torque of the auxiliary motor (6) is transmitted to the steering tie rod (4) to rotate the wheel (1).

5. The integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 1, characterized in that: The sun gear of the planetary gear mechanism (8) is connected to the auxiliary motor (6) to fix the planet carrier, and the outer gear ring of the planetary gear mechanism (8) is connected to the main transmission shaft (16) through gear meshing.

6. The integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 1, characterized in that: The energy storage mechanism comprises an inverter (9) and a power supply (10); the inverter (9) is disposed between the auxiliary motor (6) and the power supply (10); the inverter (9) is used to convert the alternating current generated during energy recovery into direct current and store it in the power supply (10); the inverter (9) is also connected to the drive motor (11) and is used to convert the direct current of the power supply (10) into alternating current when needed and supply it to the drive motor (11).

7. A control method for an integrated system of redundant vehicle steer-by-wire and auxiliary drive according to any one of claims 1 to 6, characterized in that: The following steps are involved: The VCU (12) monitors the operating state of the wire-controlled steering motor (18) and the driving torque demand Tr in real time; The VCU (12) controls the connection or disconnection of the first electromagnetic clutch (5) and the second electromagnetic clutch (7) according to whether the wire-controlled steering motor (18) fails and the driving torque demand Tr, so as to switch between the redundant safety steering mode, the auxiliary driving mode and the energy recovery mode.

8. The control method of the integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 7, characterized in that: The redundant safety steering mode includes the following steps: If the VCU (12) determines that the wire-controlled steering motor (18) fails, a redundant safety steering mode is executed; the VCU (12) controls the first electromagnetic clutch (5) to be connected, the second electromagnetic clutch (7) to be disconnected, and the auxiliary motor (6) to execute an electric mode to provide steering assistance.

9. The control method of the integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 8, characterized in that: The auxiliary driving mode includes the following steps: If the VCU (12) determines that the wire-controlled steering motor (18) has not failed, a preliminary determination of the driving torque demand Tr is performed. If Tr>0, an auxiliary driving mode is executed, and the driving torque demand Tr is determined again. If Tr≤Ta, a uniform speed driving mode is executed, the VCU (12) controls the first electromagnetic clutch (5) to be disconnected, the second electromagnetic clutch (7) to be disconnected, the VCU (12) controls the auxiliary motor (6) to stop working, and the driving motor (11) provides driving torque alone; if Tr>Ta, an acceleration driving mode is executed, the VCU (12) controls the first electromagnetic clutch (5) to be disconnected, the second electromagnetic clutch (7) to be connected, the auxiliary motor (6) to perform the auxiliary driving mode, and the driving motor (11) and the auxiliary motor (6) to provide driving torque in coordination.

10. The control method of the integrated system of redundant vehicle steer-by-wire and auxiliary drive according to claim 9, characterized in that: The energy recovery mode includes the following steps: If Tr≤0, the energy recovery mode is executed; if the energy recovery mode is executed, the VCU (12) controls the first electromagnetic clutch (5) to be disconnected, the second electromagnetic clutch (7) to be connected, the VCU (12) controls the auxiliary motor (6) to reverse, provide reverse torque, and realize power generation; the VCU (12) controls the drive motor (11) to stop working.

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