Commercial vehicle electric control power-assisted steering system and control method

Abstract

The invention provides a commercial vehicle electric control power-assisted steering system and a control method. The commercial vehicle electric control power-assisted steering system is characterized in that an upper steering column is connected with a steering wheel; the electromagnetic clutch is arranged between the upper steering column and the lower steering column and used for controlling mechanical connection and decoupling between the upper steering column and the lower steering column; the aligning and road feeling motor is mounted on the upper steering column and used for providing steering aligning torque and road feeling feedback; the electro-hydraulic power-assisted steering mechanism is connected with the lower steering column and used for providing power for wheel steering; the steering connecting rod is connected with the electro-hydraulic steering power-assisted mechanism and the wheels and used for transmitting steering torque to the wheels. And the control unit is used for controlling the connection and disconnection of the electromagnetic clutch according to the running state and the driving mode of the vehicle, and controlling the working states of the return and road feeling motor and the electro-hydraulic power-assisted steering mechanism. According to the scheme, the safety and reliability of vehicle driving are improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to an electronically controlled power steering system and a control method for a commercial vehicle. Background Art

[0002] In recent years, chassis domain control technology has become the development direction of vehicle chassis control. The first thing to achieve is the coordination of the braking and steering systems. In the process of implementing some steering assist braking functions, such as braking on an oncoming road, the system needs to automatically control the steering angle to assist in maintaining directional stability. At this time, since commercial vehicles still use the steering assist device of the Electro-Hydraulic Power Steering (EHPS), there is a rigid connection between the steering system and the steering wheel. When the system automatically performs the steering action, it will cause the steering wheel to turn, which may cause the driver to misjudge and misoperate, or even cause harm to the driver, bringing inconvenience to the development and design of the steering assist braking function.

[0003] In some exemplary technologies, a fully decoupled wire-controlled hydraulic steering system is used to solve the problem of high motor noise in traditional EPS and the inability to achieve full steering decoupling required for smart cars, and to avoid the impact of the steering system on the steering wheel when it is working automatically. However, a mechanical connection cannot be achieved, and safety is difficult to ensure when the electronic control system fails.

[0004] In other exemplary technologies, an electro-hydraulic composite steering system is used, the rotary valve structure in the traditional hydraulic power steering system is retained, and an electric power steering module is added to achieve electro-hydraulic decoupling, so that the electric power steering torque and the hydraulic power steering torque can be distributed in any proportion. However, the influence of active control on the steering wheel cannot be decoupled.

[0005] It can be seen that the main problem of the above structure is that in the chassis domain control system, when the steering system needs to actively rotate to assist the operation of the braking system, it will cause the steering wheel to rotate, which may cause the driver to misjudge and thus affect the control effect. Some fully decoupled steering systems eliminate the mechanical connection between the steering wheel and the steering gear, which can solve the problem of affecting the steering wheel during active steering. However, due to the elimination of the mechanical connection, it is difficult to ensure safety when the electronic control system fails. Therefore, the safety and reliability of vehicle driving in the prior art are poor. Summary of the invention

[0006] The present invention provides an electronically controlled power steering system and a control method for a commercial vehicle, which are used to solve the defects of poor vehicle driving safety and reliability in the prior art.

[0007] The present invention provides an electronically controlled power steering system for commercial vehicles, comprising: a steering wheel, an upper steering column, a return and road sensing motor, an electromagnetic clutch, a lower steering column, an electro-hydraulic power steering mechanism, a steering link, wheels and a control unit; The upper steering column is connected to the steering wheel; The electromagnetic clutch is arranged between the upper steering column and the lower steering column, and is used to control the mechanical connection and decoupling between the upper steering column and the lower steering column; when the electromagnetic clutch is engaged, the mechanical connection between the upper steering column and the lower steering column is controlled, and when the electromagnetic clutch is disengaged, the decoupling between the upper steering column and the lower steering column is controlled; The return and road sense motor is installed on the upper steering column, and is used to provide steering return torque and road sense feedback; The electro-hydraulic steering assist mechanism is connected to the lower steering column, and the electro-hydraulic steering assist mechanism is used to provide assistance for wheel steering; The steering link is connected to the electro-hydraulic steering assist mechanism and the wheels, and the steering link is used to transmit the steering torque to the wheels; The control unit is connected to the electromagnetic clutch, the return-to-center and road-feeling motor, and the electro-hydraulic steering assist mechanism. The control unit is used to control the engagement and disengagement of the electromagnetic clutch according to the vehicle's driving state and driving mode, and to control the working states of the return-to-center and road-feeling motor and the electro-hydraulic steering assist mechanism.

[0008] According to the commercial vehicle electronically controlled power steering system provided by the present invention, the driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode; In the driver driving mode, the control unit is used to control the electromagnetic clutch to engage and the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism is used to provide assist; In the active control mode, the control unit is used to control the electromagnetic clutch to disengage and cut off the mechanical connection between the upper steering column and the lower steering column; the electro-hydraulic steering assist mechanism is used to independently control the steering of the wheels; the return and road sense motor is used to provide road sense feedback; In the chassis domain control mode, the control unit is used to control the electromagnetic clutch to disengage and cut off the mechanical connection between the upper steering column and the lower steering column when detecting the split road condition; the electro-hydraulic steering assist mechanism is used to actively adjust the steering angle of the wheel according to the vehicle driving state to maintain the vehicle direction stability; In the driver takeover mode, the control unit is used to control the electromagnetic clutch to change from a disengaged state to an engaged state when it is detected that the driver actively turns the steering wheel and the steering angle of the steering wheel exceeds a set threshold value, and to restore the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism is used to provide assistance according to the driver's operating intention, achieve the driver's target angle, and ensure smooth switching from the active control mode or the chassis domain control mode to the driver driving mode; In the electronic control failure mode, the electromagnetic clutch automatically maintains the engagement state under the action of the mechanical spring mechanism to maintain the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism is used to provide basic hydraulic assistance to ensure emergency steering capability.

[0009] According to the commercial vehicle electronically controlled power steering system provided by the present invention, in the active control mode, the chassis domain control mode and the driver takeover mode, the return and road sense motor is used to provide road sense feedback and assist the driver's steering operation and provide necessary steering torque support; In the driver driving mode and the electronic control system failure mode, the return and road sensing motors stop working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance.

[0010] According to the commercial vehicle electronically controlled power steering system provided by the present invention, the commercial vehicle electronically controlled power steering system further comprises a steering angle sensor; The steering angle sensor is used to monitor the steering angle of the upper steering column in real time, and feed back the steering angle of the upper steering column to the control unit; The control unit is also used to determine the driver's intention to take over and switch the control mode according to the steering angle of the upper steering column.

[0011] According to the commercial vehicle electronically controlled power steering system provided by the present invention, the control unit is used to control the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, specifically for: In the active control mode, the chassis domain control mode or the driver takeover mode, an electric control signal is output to the electromagnetic clutch; and in the driver driving mode, no electric control signal is output to the electromagnetic clutch; The electromagnetic clutch is specifically used for: If an electric control signal output by the control unit is received, the control unit is in a disengaged state in response to the electric control signal to cut off the mechanical connection between the upper steering column and the lower steering column; otherwise, the control unit is in an engaged state to maintain the mechanical connection between the upper steering column and the lower steering column through its own spring mechanism; in the electric control failure mode, the engaged state is automatically maintained under the action of the mechanical spring mechanism.

[0012] The present invention also provides a control method for an electronically controlled power steering system for a commercial vehicle, which is applied to an electronically controlled power steering system for a commercial vehicle, wherein the system comprises: a steering wheel, an upper steering column, a return and road sensing motor, an electromagnetic clutch, a lower steering column, an electro-hydraulic steering assist mechanism, a steering link, wheels, and a control unit; The method comprises: The control unit determines the vehicle driving state and driving mode; The control unit controls the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, and controls the working state of the return and road sensing motor and the electro-hydraulic steering assist mechanism; Wherein, the upper steering column is connected to the steering wheel; The electromagnetic clutch is arranged between the upper steering column and the lower steering column, and is used to control the mechanical connection and decoupling between the upper steering column and the lower steering column; when the electromagnetic clutch is engaged, the mechanical connection between the upper steering column and the lower steering column is controlled, and when the electromagnetic clutch is disengaged, the decoupling between the upper steering column and the lower steering column is controlled; The return and road sense motor is installed on the upper steering column, and is used to provide steering return torque and road sense feedback; The electro-hydraulic steering assist mechanism is connected to the lower steering column, and the electro-hydraulic steering assist mechanism is used to provide assistance for wheel steering; The steering link is connected to the electro-hydraulic steering assist mechanism and the wheels, and the steering link is used to transmit the steering torque to the wheels.

[0013] According to the control method of the commercial vehicle electronically controlled power steering system provided by the present invention, the driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode; The control unit controls the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, and controls the working state of the return and road sensing motor and the electro-hydraulic steering assist mechanism, including: In the driver driving mode, the control unit controls the electromagnetic clutch to engage, the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism provides assistance; In the active control mode, the control unit controls the electromagnetic clutch to disengage, cutting off the mechanical connection between the upper steering column and the lower steering column; the electro-hydraulic steering assist mechanism independently controls the steering of the wheels; the return and road sense motor provides road sense feedback; In the chassis domain control mode, when the control unit detects the split road condition, it controls the electromagnetic clutch to disengage and cuts off the mechanical connection between the upper steering column and the lower steering column; the electro-hydraulic steering assist mechanism actively adjusts the steering angle of the wheel according to the vehicle driving state to maintain the vehicle direction stability; In the driver takeover mode, when the control unit detects that the driver actively turns the steering wheel and the steering angle of the steering wheel exceeds a set threshold, the control unit controls the electromagnetic clutch to be converted from a disengaged state to an engaged state, and restores the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism provides assistance according to the driver's operating intention to achieve the driver's target angle and ensure smooth switching from the active control mode or the chassis domain control mode to the driver driving mode; In the electronic control failure mode, the electromagnetic clutch automatically maintains the engagement state under the action of the mechanical spring mechanism to maintain the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism provides basic hydraulic assistance to ensure emergency steering capability.

[0014] According to the control method of the commercial vehicle electronically controlled power steering system provided by the present invention, the method further includes: In active control mode, chassis domain control mode and driver takeover mode, the return and road sense motor provides road sense feedback and assists the driver's steering operation, providing necessary steering torque support; In the driver driving mode and the electronic control system failure mode, the return and road sensing motors stop working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance.

[0015] According to the control method of the commercial vehicle electronically controlled power steering system provided by the present invention, the commercial vehicle electronically controlled power steering system further includes a steering angle sensor; The method further comprises: The steering angle sensor monitors the steering angle of the upper steering column in real time, and feeds back the steering angle of the upper steering column to the control unit; The control unit determines the driver's intention to take over and the switching of the control mode according to the steering angle of the upper steering column.

[0016] According to the control method of the commercial vehicle electronically controlled power steering system provided by the present invention, the control unit controls the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, including: In the active control mode, the chassis domain control mode or the driver takeover mode, the control unit outputs an electric control signal to the electromagnetic clutch; In the driver driving mode or the electronic control failure mode, the control unit does not output an electronic control signal to the electromagnetic clutch; If the electromagnetic clutch receives the electric control signal output by the control unit, the electromagnetic clutch is in a disengaged state in response to the electric control signal to cut off the mechanical connection between the upper steering column and the lower steering column; Otherwise, the electromagnetic clutch is in an engaged state to maintain the mechanical connection between the upper steering column and the lower steering column through its own spring mechanism; In the electronically controlled failure mode, the electromagnetic clutch automatically maintains the engaged state under the action of the mechanical spring mechanism.

[0017] The commercial vehicle electronically controlled power steering system and control method provided by the present invention, by setting an electromagnetic clutch between the upper and lower steering columns, and setting a return and road sensing motor on the upper steering column, can achieve a steering system function that can maintain the mechanical connection between the steering wheel and the steering gear to improve safety when the driver actively operates, and can also decouple from the steering wheel when the electronic control system actively controls the steering to avoid affecting the driver's judgment and feeling. Therefore, the solution of the present invention improves the safety and reliability of vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 The present invention is a schematic diagram of the structure of an electronically controlled power steering system for a commercial vehicle.

[0020] Figure 2It is a flow chart of a control method of an electronically controlled power steering system for a commercial vehicle provided by the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0023] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover but not exclude inclusions, for example, a product or device comprising a series of components is not necessarily limited to those components clearly listed, but may include other components not clearly listed or inherent to these products or devices. The term "unit" as used in this application refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic or combination of hardware and / or software code that can perform the functions associated with the element.

[0024] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0025] The current commercial vehicle systems with steer-by-wire functions usually use the EHPS solution, in which the input between the steering wheel and the steering column and steering gear is rigidly connected, that is, the rotation of the steering wheel will drive the rotation of the steering gear, and the movement of the wheel returning to the center position or the steering assist mechanism in response to external control will also cause the steering wheel to rotate. The main problem with the above structure is that in the chassis domain control system, when the steering system needs to actively rotate to assist the operation of the braking system, it will cause the steering wheel to rotate, which may cause the driver to misjudge and affect the control effect. Some fully decoupled steering systems eliminate the mechanical connection between the steering wheel and the steering gear, which can solve the problem of affecting the steering wheel during active steering, but due to the elimination of the mechanical connection, it is difficult to ensure safety when the electronic control system fails.

[0026] Therefore, the driving safety and reliability of the vehicles in the prior art are poor.

[0027] In view of the above technical problems, the present invention proposes the following technical concept: an electromagnetic clutch is arranged between the upper and lower steering columns, and a return and road sensing motor is arranged on the upper steering column, so as to realize a steering system function that can maintain the mechanical connection between the steering wheel and the steering gear to improve safety when the driver actively operates, and can be decoupled from the steering wheel when the electronic control system actively controls the steering to avoid affecting the driver's judgment and feeling, thereby improving the safety and stability of vehicle driving.

[0028] The following specific embodiments are used to describe in detail the technical solution of the present application and how the technical solution of the present application solves the above technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Figure 1 The present invention is described in detail with respect to an electronically controlled power steering system for a commercial vehicle.

[0029] Figure 1 Schematic diagram of the structure of the commercial vehicle electronically controlled power steering system provided by the present invention. Figure 1 As shown, the system includes: a steering wheel 1, an upper steering column 2, a return and road sensing motor 3, an electromagnetic clutch 4, a lower steering column 5, an electro-hydraulic steering assist mechanism 6, a steering link 7, a wheel 8 and a control unit 9.

[0030] Among them, the upper steering column 2 is connected to the steering wheel 1.

[0031] The electromagnetic clutch 4 is arranged between the upper steering column 2 and the lower steering column 5. The electromagnetic clutch 4 is used to control the mechanical connection and decoupling between the upper steering column 2 and the lower steering column 5. When the electromagnetic clutch 4 is engaged, the mechanical connection between the upper steering column 2 and the lower steering column 5 is controlled, and when the electromagnetic clutch 4 is disengaged, the decoupling between the upper steering column 2 and the lower steering column 5 is controlled.

[0032] The return and road sense motor 3 is installed on the upper steering column 2, and is used to provide steering return torque and road sense feedback.

[0033] The electro-hydraulic steering assist mechanism 6 is connected to the lower steering column 5 , and the electro-hydraulic steering assist mechanism 6 is used to provide steering assistance for the wheels 8 .

[0034] The steering link 7 is connected to the electro-hydraulic steering assist mechanism 6 and the wheel 8 , and the steering link 7 is used to transmit the steering torque to the wheel 8 .

[0035] The control unit 9 is connected to the electromagnetic clutch 4, the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6. The control unit 9 is used to control the engagement and disengagement of the electromagnetic clutch 4 according to the vehicle's driving state and driving mode, as well as to control the working states of the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6.

[0036] In this embodiment, the driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode.

[0037] Among them, the steering wheel 1 is a component directly operated by the driver. Specifically, in the driver driving mode, the driver controls the steering of the vehicle by turning the steering wheel 1. In the active control mode and chassis domain control mode, the steering wheel 1 is decoupled from the steering system, but the driver can still feel the road feedback through the steering wheel 1. In the driver takeover mode, the driver takes over the vehicle control by turning the steering wheel 1, and the system responds to the driver's operating intention.

[0038] The upper steering column 2 is connected to the steering wheel 1 and is connected to the lower steering column 5 through the electromagnetic clutch 4. Specifically, when the electromagnetic clutch 4 is engaged, the upper steering column 2 is mechanically connected to the lower steering column 5, and the driver's steering intention can be transmitted to the steering mechanism through mechanical transmission. When the electromagnetic clutch 4 is disengaged, the upper steering column 2 is decoupled from the lower steering column 5, and the steering system independently controls the steering of the wheels 8.

[0039] Among them, the return and road sense motor 3 is installed on the upper steering column 2 to provide steering return torque and road sense feedback. Specifically, in active control mode and chassis domain control mode, the return and road sense motor 3 provides road sense feedback to enhance the driver's driving experience. In the driver takeover mode, the return and road sense motor 3 assists the driver's steering operation and provides necessary steering torque support. In the driver driving mode and electronic control failure mode, the return and road sense motor 3 stops working, and the steering system relies on mechanical connection and hydraulic assistance to maintain basic functions.

[0040] Among them, the electromagnetic clutch 4 is arranged between the upper steering column and the lower steering column to control the mechanical connection and decoupling of the two. Specifically, in the driver driving mode and the electronic control failure mode, the electromagnetic clutch 4 is engaged, the upper steering column 2 is mechanically connected to the lower steering column 5, and the driver's steering intention can be transmitted to the steering mechanism through mechanical transmission. In the active control mode and the chassis domain control mode, the electromagnetic clutch 4 is disengaged, the upper steering column 2 is decoupled from the lower steering column 5, and the steering system independently controls the steering of the wheels. In the electronic control failure mode, the electromagnetic clutch 4 automatically maintains the engagement state under the action of the mechanical spring mechanism to ensure mechanical connection.

[0041] The lower steering column 5 is connected to the electro-hydraulic steering assist mechanism 6 for transmitting the steering torque to the steering mechanism. Specifically, when the electromagnetic clutch 4 is engaged, the lower steering column 5 receives the steering torque from the upper steering column 2 and transmits it to the electro-hydraulic steering assist mechanism 6. When the electromagnetic clutch 4 is disengaged, the lower steering column 5 independently receives the control signal of the electro-hydraulic steering assist mechanism 6 to achieve the steering of the wheel 8.

[0042] Among them, the electro-hydraulic steering assist mechanism 6 is connected to the lower steering column 5 to provide assistance for wheel steering. Specifically, in the driver driving mode, the electro-hydraulic steering assist mechanism 6 provides assistance according to the driver's steering intention to help the driver easily control the steering of the wheel 8. In the active control mode and the chassis domain control mode, the electro-hydraulic steering assist mechanism 6 independently controls the steering angle of the wheel 8 according to the instructions of the control unit. In the driver takeover mode, the electro-hydraulic steering assist mechanism 6 provides assistance according to the driver's operating intention to achieve the driver's target angle. In the electronic control failure mode, the electro-hydraulic steering assist mechanism 6 continues to provide basic hydraulic assistance to ensure emergency steering capability.

[0043] The steering link 7 connects the electro-hydraulic steering assist mechanism 6 and the wheel 8 to transfer the steering torque to the wheel. Specifically, the steering link 7 transfers the steering torque of the electro-hydraulic steering assist mechanism 6 to the wheel to realize the steering action of the wheel.

[0044] The wheel 8 receives the steering torque to realize the steering of the vehicle. The wheel 8 adjusts the steering angle according to the steering torque transmitted by the steering link 7 to realize the steering control of the vehicle.

[0045] Among them, the control unit 9 controls the engagement and disengagement of the electromagnetic clutch 4 according to the vehicle driving state and driving mode, and controls the working state of the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6. Specifically, in the driver driving mode, the control unit 9 controls the electromagnetic clutch 4 to engage, the driver's steering intention is transmitted to the steering mechanism through a mechanical connection, and the electro-hydraulic steering assist mechanism 6 provides assistance. In the active control mode, the control unit 9 disengages the electromagnetic clutch 4, the electro-hydraulic steering assist mechanism 6 independently controls the steering of the wheel 8, and the return and road sense motor 3 provides road sense feedback. In the chassis domain control mode, when the control unit 4 detects the split road condition, the electromagnetic clutch 4 is disengaged, and the electro-hydraulic steering assist mechanism 6 actively adjusts the steering angle of the wheel 8 to maintain the stability of the vehicle direction. In the driver takeover mode, when the control unit 9 detects that the driver actively turns the steering wheel and the angle exceeds the set threshold, the electromagnetic clutch 4 is engaged, and the electro-hydraulic steering assist mechanism 6 provides assistance according to the driver's operating intention to achieve the driver's target angle. In the electronic control failure mode, the electromagnetic clutch 4 automatically maintains the engaged state under the action of the mechanical spring mechanism, and the electro-hydraulic steering assist mechanism 6 provides basic hydraulic assistance to ensure emergency steering capability.

[0046] In summary, the commercial vehicle electronic power steering system achieves flexible switching of multiple driving modes through the coordinated work of various components, improving driving safety, driving experience and system intelligence. The control unit dynamically adjusts the state of the electromagnetic clutch and the output of the power mechanism according to different driving modes and vehicle driving conditions, ensuring that the system can achieve optimal steering performance under various working conditions.

[0047] It can be understood that, in this embodiment, an electromagnetic clutch 4 is provided between the upper steering column 2 and the lower steering column 5, and a return and road sensing motor 3 is provided on the upper steering column 2, thereby realizing a steering system function that can maintain the mechanical connection between the steering wheel and the steering gear to improve safety when the driver actively operates, and can decouple from the steering wheel when the electronic control system actively controls the steering to avoid affecting the driver's judgment and feeling, thereby improving the accuracy and reliability of vehicle driving.

[0048] Optionally, in some possible implementations, the above-mentioned driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode.

[0049] In the driver driving mode, the control unit 9 is used to control the engagement of the electromagnetic clutch 4 and the mechanical connection between the upper steering column 2 and the lower steering column 5 so that the driver's steering torque is transmitted to the lower steering column 5 through the mechanical connection; the electro-hydraulic steering assist mechanism 6 is used to provide assistance.

[0050] In the active control mode, the control unit 9 is used to control the electromagnetic clutch 4 to disengage, cutting off the mechanical connection between the upper steering column 2 and the lower steering column 5; the electro-hydraulic steering assist mechanism 6 is used to independently control the steering of the wheels 8; the return and road sense motor 3 is used to provide road sense feedback.

[0051] In the chassis domain control mode, the control unit 9 is used to control the electromagnetic clutch 4 to disengage and cut off the mechanical connection between the upper steering column 2 and the lower steering column 5 when the open road condition is detected; the electro-hydraulic steering assist mechanism 6 is used to actively adjust the steering angle of the wheel 8 according to the vehicle's driving state to maintain the vehicle's directional stability.

[0052] In the driver takeover mode, the control unit 9 is used to control the electromagnetic clutch 4 to change from a disengaged state to an engaged state when it detects that the driver actively turns the steering wheel 1 and the steering angle of the steering wheel 1 exceeds a set threshold, thereby restoring the mechanical connection between the upper steering column 2 and the lower steering column 5, so that the driver's steering torque can be transmitted to the lower steering column 5 through the mechanical connection; the electro-hydraulic steering assist mechanism 6 is used to provide assistance according to the driver's operating intention, achieve the driver's target angle, and ensure smooth switching from the active control mode or the chassis domain control mode to the driver driving mode.

[0053] In the electronic control failure mode, the electromagnetic clutch 4 automatically remains in the engaged state under the action of the mechanical spring mechanism to maintain the mechanical connection between the upper steering column 2 and the lower steering column 5, so that the driver's steering torque is transmitted to the lower steering column 5 through the mechanical connection; the electro-hydraulic steering assist mechanism 6 is used to provide basic hydraulic assistance to ensure emergency steering capability.

[0054] The driver driving mode refers to a mode in which the driver directly controls the steering of the vehicle through the steering wheel. For example, the application scenarios of the driver driving mode include: daily driving, the driver fully controls the steering of the vehicle, or when non-autonomous driving or assisted driving functions are enabled.

[0055] Specifically, in the driver driving mode, the electromagnetic clutch 4 is in the engaged state, and the mechanical connection between the upper and lower steering columns is maintained through its own spring mechanism. The driver turns the steering wheel 1, and the steering torque is transmitted to the electromagnetic clutch 4 through the upper steering column 2, and then to the lower steering column 5. After the electro-hydraulic steering assist mechanism 6 detects the driver's steering intention, it provides hydraulic assistance to help the wheel 8 turn. In this mode, the return and road sense motor 3 mainly provides road sense feedback to enhance the driver's perception of steering.

[0056] In actual application, in the driver driving mode, the driver fully controls the vehicle steering, the electromagnetic clutch 4 is in the engaged state, the upper steering column 2 and the lower steering column 5 are mechanically connected, and the steering wheel 1 is mechanically connected to the steering system. In this mode, the driver's steering torque is transmitted to the lower steering column 5 through the electromagnetic clutch 4, and the wheels are driven to steer under the power assistance of the electro-hydraulic power assist mechanism 6. The return and road sense motor 3 usually does not work, and the steering system mainly relies on mechanical connection and hydraulic power assistance.

[0057] Among them, active control mode refers to the mode in which the vehicle's automatic driving or assisted driving system actively controls the steering of the wheels. For example, the application scenarios of active control mode include: when the automatic driving function is enabled (such as lane keeping assist, automatic parking, etc.); when the system needs to automatically adjust the steering angle to maintain vehicle stability or perform specific driving tasks.

[0058] Specifically, in the active control mode, the electromagnetic clutch 4 separates the upper steering column 2 and the lower steering column 5 and cuts off the mechanical connection when the automatic driving or assisted driving system issues a steering request. The electro-hydraulic steering assist mechanism 6 independently controls the steering angle of the wheel 8 according to the system command to realize the automatic driving or assisted driving function. Since the electromagnetic clutch 4 is separated, the steering wheel 1 will not rotate with the steering of the wheel to avoid interference to the driver. In this mode, the return and road sense motor 3 mainly provides road sense feedback or simulates steering resistance to enhance the driver's perception.

[0059] In actual application, in active control mode, the automatic driving system controls the steering of the wheels. When the automatic driving or assisted driving system issues a steering request, the control unit 9 controls the electromagnetic clutch 4 to disengage and controls the electro-hydraulic power-assisting mechanism 6 to drive the wheels 8 to steer. At this time, since the upper steering column 2 and the lower steering column 5 are decoupled, the steering wheel 1 will not rotate, thereby avoiding interference with the driver's decision-making and damage to the driver caused by the rotation of the steering wheel 1.

[0060] The chassis domain control mode refers to a mode in which the vehicle chassis control system actively adjusts the steering angle according to the vehicle's driving state. For example, the application scenarios of the chassis domain control mode include: when the vehicle is driving on complex roads (such as split roads, slippery roads); when the system needs to actively intervene in the steering to maintain the stability of the vehicle's direction.

[0061] Specifically, in the chassis domain control mode, when the system detects the condition of the split road, the control unit 9 controls the electromagnetic clutch 4 to disengage, thereby separating the upper steering column 2 and the lower steering column 5. The electro-hydraulic steering assist mechanism 6 actively controls the wheel 8 to deflect to a certain angle to the high adhesion side (when driving) or the low adhesion side (when braking) according to the instructions of the chassis domain control system to maintain the stability of the vehicle direction. The steering angle sensor monitors the steering angle of the upper steering column 2 in real time and provides feedback to the system. In this mode, the return and road sense motor 3 provides auxiliary steering torque or road sense feedback to enhance system stability.

[0062] In actual applications, in chassis domain control mode, the chassis control system actively adjusts the steering angle. When accelerating or braking on a split road (i.e., one side of the left and right wheels is at high attachment and the other side is at low attachment), the vehicle will yaw due to the difference in braking / driving force on both sides. When the system detects split road conditions, if the driver does not make a steering correction operation, the chassis domain controller intervenes in the control, first disconnecting the electromagnetic clutch 4, and then actively controlling the power-assisting mechanism 6 to deflect to the high attachment side (when driving) or the low attachment side (when braking) by a certain angle (the deflection angle is determined according to the actual vehicle driving acceleration or braking intensity, and according to the actual vehicle test calibration), so that at this time, with the assistance of the steering system, the direction is automatically maintained stable without the need for manual correction by the driver, reducing the requirements for the driver's driving skills.

[0063] The driver takeover mode refers to the mode in which the driver actively intervenes in the steering operation in the active control mode or chassis domain control mode, and the system switches the control from the automatic driving or chassis domain control system to the driver. For example, the application scenarios of the driver takeover mode include: when the driver needs to take over the vehicle control (such as when the automatic driving system is about to exit or the driver actively intervenes); when the driver turns the steering wheel beyond the set threshold.

[0064] Specifically, in the driver takeover mode, the steering angle sensor monitors the driver's operating intention in real time. The electro-hydraulic steering assist mechanism 6 adjusts the wheel steering according to the driver's target angle to ensure a smooth transition. The return and road sensing motor 3 assists the driver in operation and enhances the driving experience.

[0065] In actual application, the driver actively intervenes in steering in the driver takeover mode, and the system smoothly switches control rights. For example, when the angle sensor detects that the upper steering column 2 rotates more than a certain angle under the control of the driver in the active control mode, the driver's target angle is mainly achieved through the electro-hydraulic steering assist mechanism 6. And in the process of switching from the active control mode to the chassis domain control mode, the angle output by the electro-hydraulic steering assist mechanism 6 is smoothed to prevent large mutations.

[0066] The system electronic control failure mode refers to a mode in which the steering system switches to a mechanical backup mode when the electronic control system fails, ensuring that the vehicle still has basic steering capabilities. For example, the application scenarios of the system electronic control failure mode include: when the electronic control system fails or fails; when the system detects that the electronic control signal is lost or abnormal.

[0067] Specifically, in the system electronic control failure mode, when the electronic control system fails, the electromagnetic clutch 4 automatically engages under the action of the mechanical spring mechanism to maintain the mechanical connection between the upper steering column 2 and the lower steering column 5. The electro-hydraulic steering assist mechanism 6 continues to provide basic hydraulic assistance to ensure that the driver can manually control the steering of the wheel 8 through the steering wheel 1. The return and road sensing motor 3 stops working, and the steering system relies on mechanical connection and hydraulic assistance to maintain basic functions.

[0068] In actual application, when the electronic control system fails, the steering system switches to the mechanical backup mode to ensure emergency steering capability. The electromagnetic clutch 4 remains engaged under the action of the mechanical system, maintaining the mechanical connection between the upper steering column 2 and the lower steering column 5. The system still has the basic mechanical system and hydraulic power assistance capabilities to ensure safety when the electronic control system fails.

[0069] In this embodiment, the driver driving mode can provide direct mechanical connection and power support to enhance the driving experience. The active control mode supports the automatic driving function, reduces driver interference, and provides road feel feedback. The chassis domain control mode can adapt to complex road surfaces, dynamically adjust the steering angle, and improve driving stability. The driver takeover mode can quickly respond to driver operations, ensure smooth transitions, and improve driving safety. The system electronic control failure mode can provide mechanical backup and emergency steering capabilities to ensure system reliability. The design of these modes not only meets the needs of different driving scenarios, but also significantly improves the steering performance and safety of commercial vehicles through intelligent control.

[0070] Optionally, in some possible implementation modes, in active control mode, chassis domain control mode and driver takeover mode, the return-to-center and road sense motor 3 is used to provide road sense feedback, assist the driver's steering operation, and provide necessary steering torque support; in driver driving mode and electronic control system failure mode, the return-to-center and road sense motor 3 stops working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance.

[0071] It is understandable that, on the one hand, the return and road sense motor 3 provides road sense feedback in the active control mode, the chassis domain control mode and the driver takeover mode, which can enhance the driving experience, reduce misoperation, and ensure the stable transition of the mode in the driver takeover mode. Specifically, in the automatic driving or chassis domain control mode, the steering wheel 1 is decoupled from the steering system, and the return and road sense motor 3 can still provide simulated road sense feedback. This enables the driver to feel a certain steering resistance, enhance the perception of the vehicle state, and improve the driving experience. Road sense feedback can help the driver better judge the driving state of the vehicle, especially in complex road conditions or automatic driving mode. This feedback reduces misoperation caused by lack of road sense and improves driving safety. In the driver takeover mode, the return and road sense motor 3 assists the driver's steering operation and provides the necessary steering torque support. This ensures a smooth transition from the automatic driving or chassis domain control mode to the driver's driving mode, avoids mutations caused by mode switching, and further improves the stability and safety of driving.

[0072] On the other hand, the return and road sense motor 3 assists the driver's steering operation in the active control mode, chassis domain control mode and driver takeover mode, which can reduce the driving difficulty and improve the system response speed. Specifically, under complex working conditions (such as split roads and slippery roads), the auxiliary steering torque provided by the return and road sense motor 3 can help the driver control the wheel steering more easily and reduce the driving difficulty. Especially in emergency situations, it can quickly respond to the driver's operating intentions and maintain vehicle stability. The return and road sense motor 3 can quickly provide steering torque support, enhance the system's response speed, and ensure that the steering system's actions are more accurate and timely in automatic driving or chassis domain control mode.

[0073] On the other hand, the return and road sense motor 3 stops working in the driver driving mode and the electronic control system failure mode. In the driver driving mode, the return and road sense motor 3 stops working, and the steering system relies entirely on mechanical connection and hydraulic assistance to maintain basic functions. This retains the reliability and directness of the traditional steering system, ensuring that in non-automatic driving mode, the driver can directly control the vehicle through the mechanical system. In the electronic control system failure mode, the return and road sense motor 3 stops working, and the steering system relies on mechanical connection and hydraulic assistance to maintain basic functions. This design ensures that when the electronic control system fails completely, the vehicle still has emergency steering capabilities, and the driver can manually control the vehicle through the mechanical system, reducing safety risks caused by system failures. By stopping the return and road sense motor 3 in the electronic control failure mode, the system relies on mechanical backup to maintain basic functions, improving the reliability and safety of the system.

[0074] In this embodiment, in the active control mode, chassis domain control mode and driver takeover mode, the return and road sense motor 3 is used to provide road sense feedback and assist the driver's steering operation and provide necessary steering torque support; in the driver driving mode and electronic control system failure mode, the return and road sense motor 3 stops working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance. This embodiment not only improves the intelligence level of the commercial vehicle electronic control power steering system, but also significantly improves the system safety and driving experience through dynamic adjustment capabilities.

[0075] Optionally, in a possible implementation manner, the above-mentioned commercial vehicle electronically controlled power steering system further includes a steering angle sensor; The steering angle sensor is used to monitor the steering angle of the upper steering column 2 in real time, and feed back the steering angle of the upper steering column 2 to the control unit 9; The control unit 9 is also used to determine the driver's intention to take over and switch the control mode according to the steering angle of the upper steering column 2.

[0076] Specifically, in the chassis domain control mode, the steering angle sensor monitors the steering angle of the upper steering column 2 in real time and provides feedback to the system.

[0077] Specifically, in the driver takeover mode, the steering angle sensor monitors the driver's operating intention in real time. The electro-hydraulic steering assist mechanism 6 adjusts the wheel steering according to the driver's target angle to ensure a smooth transition. The return and road sensing motor 3 assists the driver in operation and enhances the driving experience.

[0078] In this embodiment, the steering angle sensor can monitor the steering angle of the upper steering column in real time and feed the data back to the control unit 9. This real-time monitoring capability enables the system to accurately sense the steering state of the steering wheel and provide accurate data support for subsequent control decisions. By monitoring the steering angle in real time, the system can respond to the driver's operating intentions in a timely manner, reduce control errors caused by data delays or inaccuracies, and thus improve the overall reliability of the system. Accordingly, when the steering angle sensor detects that the driver actively turns the steering wheel 1 and the angle exceeds the set threshold, the control unit 9 can quickly determine the driver's intention to take over vehicle control. This rapid response capability ensures that the system can smoothly and promptly return control to the driver at critical moments. In automatic driving or chassis domain control mode, the driver may need to take over vehicle control at any time. The introduction of the steering angle sensor enables the system to detect the driver's intention to take over in a timely manner, avoiding safety risks caused by system delays, thereby significantly improving driving safety.

[0079] Optionally, in a possible implementation manner, the control unit 9 is used to control the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, specifically for: In the active control mode, the chassis domain control mode or the driver takeover mode, an electric control signal is output to the electromagnetic clutch 4 ; and, in the driver driving mode, no electric control signal is output to the electromagnetic clutch 4 .

[0080] The electromagnetic clutch 4 is specifically used for: If an electric control signal output by the control unit 9 is received, it is in a disengaged state in response to the electric control signal to cut off the mechanical connection between the upper steering column 2 and the lower steering column 5; otherwise, it is in an engaged state to maintain the mechanical connection between the upper steering column 2 and the lower steering column 5 through its own spring mechanism; in the electric control failure mode, the engaged state is automatically maintained under the action of the mechanical spring mechanism.

[0081] It should be noted that in the electronic control failure mode, even if the control unit 9 fails completely and cannot output a control signal, the electromagnetic clutch 4 automatically maintains the engagement state through the mechanical spring mechanism, which can ensure the mechanical connection between the upper steering column 2 and the lower steering column 5. This design ensures emergency steering capability and significantly improves the reliability and safety of the system.

[0082] In this embodiment, on the one hand, the control unit 9 accurately controls the engagement and disengagement of the electromagnetic clutch 4 by outputting an electric control signal, and the system can quickly switch the working mode according to different driving needs, reduce the driving risk caused by inaccurate mode switching, and improve the reliability and safety of the system. On the other hand, in the case of failure of the electronic control system, the electromagnetic clutch 4 can automatically maintain the engagement state under the action of the mechanical spring mechanism. This design ensures that even if the electronic control system fails completely, the vehicle can still maintain the basic steering function through mechanical connection. On the other hand, in the driver takeover mode, the control unit 9 can quickly output the electric control signal to disengage the electromagnetic clutch 4, ensuring that the driver's operation can be immediately transmitted to the steering system. This rapid response capability improves driving safety, especially in emergency situations. On the other hand, during the mode switching process, the response of the electromagnetic clutch 4 ensures a smooth transition of the steering system, avoids sudden changes caused by mode switching, and improves driving comfort. On the other hand, the engagement and disengagement states of the electromagnetic clutch 4 are dynamically adjusted according to the driving mode, so that the system can adapt to a variety of driving scenarios from automatic driving to manual driving, and improves the adaptability and flexibility of the system. Therefore, this embodiment not only improves the performance of the system, but also provides strong support for the development of automatic driving and intelligent driving technology.

[0083] In the commercial vehicle electronically controlled power steering system provided by the present embodiment, the upper steering column 2 is connected to the steering wheel 1; the electromagnetic clutch 4 is arranged between the upper steering column 2 and the lower steering column 5, and is used to control the mechanical connection and decoupling between the upper steering column 2 and the lower steering column 5; when the electromagnetic clutch 4 is engaged, the mechanical connection between the upper steering column 2 and the lower steering column 5 is achieved, and when the electromagnetic clutch 4 is disengaged, the decoupling between the upper steering column 2 and the lower steering column 5 is achieved; the return and road sense motor 3 is installed on the upper steering column 2, and is used to provide steering return torque and road sense feedback; the electro-hydraulic steering assist mechanism 6 is connected to the lower steering column 5, and is used to provide assistance for wheel steering; the steering link 7 is connected to the electro-hydraulic steering assist mechanism 6 and the wheel 8, and is used to transmit the steering torque to the wheel 8; the control unit 9 is connected to the electromagnetic clutch 4, the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6, and is used to control the engagement and separation of the electromagnetic clutch 4 according to the vehicle driving state and driving mode, and to control the working state of the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6. The solution of this embodiment is to set an electromagnetic clutch between the upper and lower steering columns, and set a return and road sensing motor on the upper steering column, so as to achieve a steering system function that can maintain the mechanical connection between the steering wheel and the steering gear to improve safety when the driver actively operates, and can decouple from the steering wheel when the electronic control system actively controls the steering to avoid affecting the driver's judgment and feeling. Therefore, the solution of the present invention improves the safety and reliability of vehicle driving.

[0084] In some embodiments, the present invention also provides a control method for an electronically controlled power steering system for a commercial vehicle. The control method is applied to an electronically controlled power steering system for a commercial vehicle. The system includes: a steering wheel 1, an upper steering column 2, a return and road sensing motor 3, an electromagnetic clutch 4, a lower steering column 5, an electro-hydraulic steering assist mechanism 6, a steering link 7, a wheel 8 and a control unit 9.

[0085] Figure 2 FIG. 1 is a flow chart of a control method for an electronically controlled power steering system for a commercial vehicle provided by the present invention. Figure 2 As shown, the method includes: step 201 and step 202.

[0086] Step 201: The control unit 1 determines the vehicle driving state and driving mode.

[0087] Step 202 , the control unit 2 controls the engagement and disengagement of the electromagnetic clutch 4 according to the vehicle driving state and driving mode, and controls the working states of the return and road sensing motor 3 and the electro-hydraulic steering assist mechanism 6 .

[0088] Among them, the upper steering column 2 is connected to the steering wheel 1.

[0089] The electromagnetic clutch 4 is arranged between the upper steering column 2 and the lower steering column 5. The electromagnetic clutch 4 is used to control the mechanical connection and decoupling between the upper steering column 2 and the lower steering column 5. When the electromagnetic clutch 4 is engaged, the mechanical connection between the upper steering column 2 and the lower steering column 5 is controlled, and when the electromagnetic clutch 4 is disengaged, the decoupling between the upper steering column 2 and the lower steering column 5 is controlled.

[0090] The return and road sense motor 3 is installed on the upper steering column 2, and is used to provide steering return torque and road sense feedback.

[0091] The electro-hydraulic steering assist mechanism 6 is connected to the lower steering column 5 , and the electro-hydraulic steering assist mechanism 6 is used to provide steering assistance for the wheels 8 .

[0092] The steering link 7 is connected to the electro-hydraulic steering assist mechanism 6 and the wheel 8 , and the steering link 7 is used to transmit the steering torque to the wheel 8 .

[0093] In this embodiment, the driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode.

[0094] Among them, the steering wheel 1 is a component directly operated by the driver. Specifically, in the driver driving mode, the driver controls the steering of the vehicle by turning the steering wheel 1. In the active control mode and chassis domain control mode, the steering wheel 1 is decoupled from the steering system, but the driver can still feel the road feedback through the steering wheel 1. In the driver takeover mode, the driver takes over the vehicle control by turning the steering wheel 1, and the system responds to the driver's operating intention.

[0095] The upper steering column 2 is connected to the steering wheel 1 and is connected to the lower steering column 5 through the electromagnetic clutch 4. Specifically, when the electromagnetic clutch 4 is engaged, the upper steering column 2 is mechanically connected to the lower steering column 5, and the driver's steering intention can be transmitted to the steering mechanism through mechanical transmission. When the electromagnetic clutch 4 is disengaged, the upper steering column 2 is decoupled from the lower steering column 5, and the steering system independently controls the steering of the wheels 8.

[0096] Among them, the return and road sense motor 3 is installed on the upper steering column 2 to provide steering return torque and road sense feedback. Specifically, in active control mode and chassis domain control mode, the return and road sense motor 3 provides road sense feedback to enhance the driver's driving experience. In the driver takeover mode, the return and road sense motor 3 assists the driver's steering operation and provides necessary steering torque support. In the driver driving mode and electronic control failure mode, the return and road sense motor 3 stops working, and the steering system relies on mechanical connection and hydraulic assistance to maintain basic functions.

[0097] Among them, the electromagnetic clutch 4 is arranged between the upper steering column and the lower steering column to control the mechanical connection and decoupling of the two. Specifically, in the driver driving mode and the electronic control failure mode, the electromagnetic clutch 4 is engaged, the upper steering column 2 is mechanically connected to the lower steering column 5, and the driver's steering intention can be transmitted to the steering mechanism through mechanical transmission. In the active control mode and the chassis domain control mode, the electromagnetic clutch 4 is disengaged, the upper steering column 2 is decoupled from the lower steering column 5, and the steering system independently controls the steering of the wheels. In the electronic control failure mode, the electromagnetic clutch 4 automatically maintains the engagement state under the action of the mechanical spring mechanism to ensure mechanical connection.

[0098] The lower steering column 5 is connected to the electro-hydraulic steering assist mechanism 6 for transmitting the steering torque to the steering mechanism. Specifically, when the electromagnetic clutch 4 is engaged, the lower steering column 5 receives the steering torque from the upper steering column 2 and transmits it to the electro-hydraulic steering assist mechanism 6. When the electromagnetic clutch 4 is disengaged, the lower steering column 5 independently receives the control signal of the electro-hydraulic steering assist mechanism 6 to achieve the steering of the wheel 8.

[0099] Among them, the electro-hydraulic steering assist mechanism 6 is connected to the lower steering column 5 to provide assistance for wheel steering. Specifically, in the driver driving mode, the electro-hydraulic steering assist mechanism 6 provides assistance according to the driver's steering intention to help the driver easily control the steering of the wheel 8. In the active control mode and the chassis domain control mode, the electro-hydraulic steering assist mechanism 6 independently controls the steering angle of the wheel 8 according to the instructions of the control unit. In the driver takeover mode, the electro-hydraulic steering assist mechanism 6 provides assistance according to the driver's operating intention to achieve the driver's target angle. In the electronic control failure mode, the electro-hydraulic steering assist mechanism 6 continues to provide basic hydraulic assistance to ensure emergency steering capability.

[0100] The steering link 7 connects the electro-hydraulic steering assist mechanism 6 and the wheel 8 to transfer the steering torque to the wheel. Specifically, the steering link 7 transfers the steering torque of the electro-hydraulic steering assist mechanism 6 to the wheel to realize the steering action of the wheel.

[0101] The wheel 8 receives the steering torque to realize the steering of the vehicle. The wheel 8 adjusts the steering angle according to the steering torque transmitted by the steering link 7 to realize the steering control of the vehicle.

[0102] Among them, the control unit 9 controls the engagement and disengagement of the electromagnetic clutch 4 according to the vehicle driving state and driving mode, and controls the working state of the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6. Specifically, in the driver driving mode, the control unit 9 controls the electromagnetic clutch 4 to engage, the driver's steering intention is transmitted to the steering mechanism through a mechanical connection, and the electro-hydraulic steering assist mechanism 6 provides assistance. In the active control mode, the control unit 9 disengages the electromagnetic clutch 4, the electro-hydraulic steering assist mechanism 6 independently controls the steering of the wheel 8, and the return and road sense motor 3 provides road sense feedback. In the chassis domain control mode, when the control unit 4 detects the split road condition, the electromagnetic clutch 4 is disengaged, and the electro-hydraulic steering assist mechanism 6 actively adjusts the steering angle of the wheel 8 to maintain the stability of the vehicle direction. In the driver takeover mode, when the control unit 9 detects that the driver actively turns the steering wheel and the angle exceeds the set threshold, the electromagnetic clutch 4 is engaged, and the electro-hydraulic steering assist mechanism 6 provides assistance according to the driver's operating intention to achieve the driver's target angle. In the electronic control failure mode, the electromagnetic clutch 4 automatically maintains the engaged state under the action of the mechanical spring mechanism, and the electro-hydraulic steering assist mechanism 6 provides basic hydraulic assistance to ensure emergency steering capability.

[0103] In summary, the commercial vehicle electronic power steering system achieves flexible switching of multiple driving modes through the coordinated work of various components, improving driving safety, driving experience and system intelligence. The control unit dynamically adjusts the state of the electromagnetic clutch and the output of the power mechanism according to different driving modes and vehicle driving conditions, ensuring that the system can achieve optimal steering performance under various working conditions.

[0104] It can be understood that, in this embodiment, an electromagnetic clutch 4 is provided between the upper steering column 2 and the lower steering column 5, and a return and road sensing motor 3 is provided on the upper steering column 2, thereby realizing a steering system function that can maintain the mechanical connection between the steering wheel and the steering gear to improve safety when the driver actively operates, and can decouple from the steering wheel when the electronic control system actively controls the steering to avoid affecting the driver's judgment and feeling, thereby improving the accuracy and reliability of vehicle driving.

[0105] Optionally, in some embodiments, the above-mentioned driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode.

[0106] The above step 202 includes: In the driver driving mode, the control unit 9 controls the electromagnetic clutch 4 to engage, and the upper steering column 2 and the lower steering column 5 are mechanically connected so that the driver's steering torque is transmitted to the lower steering column 5 through the mechanical connection; the electro-hydraulic steering assist mechanism 6 provides assistance.

[0107] In the active control mode, the control unit 9 controls the electromagnetic clutch 4 to disengage, cutting off the mechanical connection between the upper steering column 2 and the lower steering column 5; the electro-hydraulic steering assist mechanism 6 independently controls the steering of the wheels 8; and the return and road sense motor 3 provides road sense feedback.

[0108] In the chassis domain control mode, when the control unit 9 detects the open road condition, it controls the electromagnetic clutch 4 to disengage and cuts off the mechanical connection between the upper steering column 2 and the lower steering column 5; the electro-hydraulic steering assist mechanism 6 actively adjusts the steering angle of the wheel 8 according to the vehicle's driving state to maintain the vehicle's directional stability.

[0109] In the driver takeover mode, when the control unit 9 detects that the driver actively turns the steering wheel 1 and the steering angle of the steering wheel 1 exceeds the set threshold, it controls the electromagnetic clutch 4 to change from a disengaged state to an engaged state, and restores the mechanical connection between the upper steering column 2 and the lower steering column 5, so that the driver's steering torque is transmitted to the lower steering column 5 through the mechanical connection; the electro-hydraulic steering assist mechanism 6 provides assistance according to the driver's operating intention to achieve the driver's target angle and ensure smooth switching from the active control mode or the chassis domain control mode to the driver driving mode.

[0110] In the electronic control failure mode, the electromagnetic clutch 4 automatically remains in the engaged state under the action of the mechanical spring mechanism to maintain the mechanical connection between the upper steering column 2 and the lower steering column 5, so that the driver's steering torque is transmitted to the lower steering column 5 through the mechanical connection; the electro-hydraulic steering assist mechanism 6 is used to provide basic hydraulic assistance to ensure emergency steering capability.

[0111] In this embodiment, the driver driving mode can provide direct mechanical connection and power support to enhance the driving experience. The active control mode supports the automatic driving function, reduces driver interference, and provides road feel feedback. The chassis domain control mode can adapt to complex road surfaces, dynamically adjust the steering angle, and improve driving stability. The driver takeover mode can quickly respond to driver operations, ensure smooth transitions, and improve driving safety. The system electronic control failure mode can provide mechanical backup and emergency steering capabilities to ensure system reliability. The design of these modes not only meets the needs of different driving scenarios, but also significantly improves the steering performance and safety of commercial vehicles through intelligent control.

[0112] Optionally, in some possible implementations, the above method further includes: In active control mode, chassis domain control mode and driver takeover mode, the return and road sense motor 3 provides road sense feedback and assists the driver's steering operation, providing necessary steering torque support; In the driver driving mode and the electronic control system failure mode, the return and road sensing motor 3 stops working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance.

[0113] In this embodiment, in the active control mode, chassis domain control mode and driver takeover mode, the return and road sense motor 3 is used to provide road sense feedback and assist the driver's steering operation and provide necessary steering torque support; in the driver driving mode and electronic control system failure mode, the return and road sense motor 3 stops working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance. This embodiment not only improves the intelligence level of the commercial vehicle electronic control power steering system, but also significantly improves the system safety and driving experience through dynamic adjustment capabilities.

[0114] Optionally, in a possible implementation manner, the above-mentioned commercial vehicle electronically controlled power steering system further includes a steering angle sensor; The above method further includes: The steering angle sensor monitors the steering angle of the upper steering column 2 in real time, and feeds back the steering angle of the upper steering column 2 to the control unit 9; The control unit 9 determines the driver's intention to take over and the switching of the control mode according to the steering angle of the upper steering column 2.

[0115] In this embodiment, the steering angle sensor can monitor the steering angle of the upper steering column in real time and feed the data back to the control unit 9. This real-time monitoring capability enables the system to accurately sense the steering state of the steering wheel and provide accurate data support for subsequent control decisions. By monitoring the steering angle in real time, the system can respond to the driver's operating intentions in a timely manner, reduce control errors caused by data delays or inaccuracies, and thus improve the overall reliability of the system. Accordingly, when the steering angle sensor detects that the driver actively turns the steering wheel 1 and the angle exceeds the set threshold, the control unit 9 can quickly determine the driver's intention to take over vehicle control. This rapid response capability ensures that the system can smoothly and promptly return control to the driver at critical moments. In automatic driving or chassis domain control mode, the driver may need to take over vehicle control at any time. The introduction of the steering angle sensor enables the system to detect the driver's intention to take over in a timely manner, avoiding safety risks caused by system delays, thereby significantly improving driving safety.

[0116] Optionally, in a possible implementation manner, in the above step 202, the control unit 9 controls the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, including: In the active control mode, the chassis domain control mode or the driver takeover mode, the control unit 9 outputs an electric control signal to the electromagnetic clutch 4; In the driver driving mode, the control unit 9 does not output an electric control signal to the electromagnetic clutch 4 .

[0117] If the electromagnetic clutch 4 receives the electric control signal output by the control unit 9, it is in a disengaged state in response to the electric control signal to cut off the mechanical connection between the upper steering column 2 and the lower steering column 5; Otherwise, the electromagnetic clutch 4 is in an engaged state to maintain the mechanical connection between the upper steering column 2 and the lower steering column 5 through its own spring mechanism; In the electronic control failure mode, the electromagnetic clutch 4 automatically maintains the engagement state under the action of the mechanical spring mechanism.

[0118] It should be noted that in the electronic control failure mode, even if the control unit 9 fails completely and cannot output a control signal, the electromagnetic clutch 4 automatically maintains the engagement state through the mechanical spring mechanism, which can ensure the mechanical connection between the upper steering column 2 and the lower steering column 5. This design ensures emergency steering capability and significantly improves the reliability and safety of the system.

[0119] In this embodiment, on the one hand, the control unit 9 accurately controls the engagement and disengagement of the electromagnetic clutch 4 by outputting an electric control signal, and the system can quickly switch the working mode according to different driving needs, reduce the driving risk caused by inaccurate mode switching, and improve the reliability and safety of the system. On the other hand, in the case of failure of the electronic control system, the electromagnetic clutch 4 can automatically maintain the engagement state under the action of the mechanical spring mechanism. This design ensures that even if the electronic control system fails completely, the vehicle can still maintain the basic steering function through mechanical connection. On the other hand, in the driver takeover mode, the control unit 9 can quickly output the electric control signal to disengage the electromagnetic clutch 4, ensuring that the driver's operation can be immediately transmitted to the steering system. This rapid response capability improves driving safety, especially in emergency situations. On the other hand, during the mode switching process, the response of the electromagnetic clutch 4 ensures a smooth transition of the steering system, avoids sudden changes caused by mode switching, and improves driving comfort. On the other hand, the engagement and disengagement states of the electromagnetic clutch 4 are dynamically adjusted according to the driving mode, so that the system can adapt to a variety of driving scenarios from automatic driving to manual driving, and improves the adaptability and flexibility of the system. Therefore, this embodiment not only improves the performance of the system, but also provides strong support for the development of automatic driving and intelligent driving technology.

[0120] In the commercial vehicle electronically controlled power steering system provided by the present embodiment, the upper steering column 2 is connected to the steering wheel 1; the electromagnetic clutch 4 is arranged between the upper steering column 2 and the lower steering column 5, and is used to control the mechanical connection and decoupling between the upper steering column 2 and the lower steering column 5; when the electromagnetic clutch 4 is engaged, the mechanical connection between the upper steering column 2 and the lower steering column 5 is achieved, and when the electromagnetic clutch 4 is disengaged, the decoupling between the upper steering column 2 and the lower steering column 5 is achieved; the return and road sense motor 3 is installed on the upper steering column 2, and is used to provide steering return torque and road sense feedback; the electro-hydraulic steering assist mechanism 6 is connected to the lower steering column 5, and is used to provide assistance for wheel steering; the steering link 7 is connected to the electro-hydraulic steering assist mechanism 6 and the wheel 8, and is used to transmit the steering torque to the wheel 8; the control unit 9 is connected to the electromagnetic clutch 4, the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6, and is used to control the engagement and separation of the electromagnetic clutch 4 according to the vehicle driving state and driving mode, and to control the working state of the return and road sense motor 3 and the electro-hydraulic steering assist mechanism 6. The solution of this embodiment is to set an electromagnetic clutch between the upper and lower steering columns, and set a return and road sensing motor on the upper steering column, so as to achieve a steering system function that can maintain the mechanical connection between the steering wheel and the steering gear to improve safety when the driver actively operates, and can decouple from the steering wheel when the electronic control system actively controls the steering to avoid affecting the driver's judgment and feeling. Therefore, the solution of the present invention improves the safety and reliability of vehicle driving.

[0121] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0122] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electronically controlled power steering system for a commercial vehicle, characterized in that: include: Steering wheel, upper steering column, return and road sensing motor, electromagnetic clutch, lower steering column, electro-hydraulic power steering mechanism, steering linkage, wheels and control unit; The upper steering column is connected to the steering wheel; The electromagnetic clutch is arranged between the upper steering column and the lower steering column, and is used to control the mechanical connection and decoupling between the upper steering column and the lower steering column; when the electromagnetic clutch is engaged, the mechanical connection between the upper steering column and the lower steering column is controlled, and when the electromagnetic clutch is disengaged, the decoupling between the upper steering column and the lower steering column is controlled; The return and road sense motor is installed on the upper steering column, and is used to provide steering return torque and road sense feedback; The electro-hydraulic steering assist mechanism is connected to the lower steering column, and the electro-hydraulic steering assist mechanism is used to provide assistance for wheel steering; The steering link is connected to the electro-hydraulic steering assist mechanism and the wheels, and the steering link is used to transmit the steering torque to the wheels; The control unit is connected to the electromagnetic clutch, the return-to-center and road-feeling motor, and the electro-hydraulic steering assist mechanism. The control unit is used to control the engagement and disengagement of the electromagnetic clutch according to the vehicle's driving state and driving mode, and to control the working states of the return-to-center and road-feeling motor and the electro-hydraulic steering assist mechanism.

2. The commercial vehicle electronically controlled power steering system according to claim 1, characterized in that: The driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode; In the driver driving mode, the control unit is used to control the electromagnetic clutch to engage and the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism is used to provide assist; In the active control mode, the control unit is used to control the electromagnetic clutch to disengage and cut off the mechanical connection between the upper steering column and the lower steering column; the electro-hydraulic steering assist mechanism is used to independently control the steering of the wheels; the return and road sense motor is used to provide road sense feedback; In the chassis domain control mode, the control unit is used to control the electromagnetic clutch to disengage and cut off the mechanical connection between the upper steering column and the lower steering column when detecting the split road condition; the electro-hydraulic steering assist mechanism is used to actively adjust the steering angle of the wheel according to the vehicle driving state to maintain the vehicle direction stability; In the driver takeover mode, the control unit is used to control the electromagnetic clutch to change from a disengaged state to an engaged state when it is detected that the driver actively turns the steering wheel and the steering angle of the steering wheel exceeds a set threshold value, and to restore the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism is used to provide assistance according to the driver's operating intention, achieve the driver's target angle, and ensure smooth switching from the active control mode or the chassis domain control mode to the driver driving mode; In the electronic control failure mode, the electromagnetic clutch automatically maintains the engagement state under the action of the mechanical spring mechanism to maintain the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism is used to provide basic hydraulic assistance to ensure emergency steering capability.

3. The commercial vehicle electronically controlled power steering system according to claim 2, characterized in that: In the active control mode, the chassis domain control mode and the driver takeover mode, the return and road sense motor is used to provide road sense feedback and assist the driver's steering operation and provide necessary steering torque support; In the driver driving mode and the electronic control system failure mode, the return and road sensing motors stop working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance.

4. The commercial vehicle electronically controlled power steering system according to claim 1, characterized in that: The commercial vehicle electronically controlled power steering system further includes a steering angle sensor; The steering angle sensor is used to monitor the steering angle of the upper steering column in real time, and feed back the steering angle of the upper steering column to the control unit; The control unit is also used to determine the driver's intention to take over and switch the control mode according to the steering angle of the upper steering column.

5. The commercial vehicle electronically controlled power steering system according to any one of claims 2 to 4, characterized in that: The control unit is used to control the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, specifically for: In the active control mode, the chassis domain control mode or the driver takeover mode, an electric control signal is output to the electromagnetic clutch; and in the driver driving mode, no electric control signal is output to the electromagnetic clutch; The electromagnetic clutch is specifically used for: If an electric control signal output by the control unit is received, the control unit is in a disengaged state in response to the electric control signal to cut off the mechanical connection between the upper steering column and the lower steering column; otherwise, the control unit is in an engaged state to maintain the mechanical connection between the upper steering column and the lower steering column through its own spring mechanism; in the electric control failure mode, the engaged state is automatically maintained under the action of the mechanical spring mechanism.

6. A control method for an electronically controlled power steering system of a commercial vehicle, characterized in that: Applied to the electronically controlled power steering system of commercial vehicles, the system includes: steering wheel, upper steering column, return and road sensing motor, electromagnetic clutch, lower steering column, electro-hydraulic power steering mechanism, steering linkage, wheels and control unit; The method comprises: The control unit determines the vehicle driving state and driving mode; The control unit controls the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, and controls the working state of the return and road sensing motor and the electro-hydraulic steering assist mechanism; Wherein, the upper steering column is connected to the steering wheel; The electromagnetic clutch is arranged between the upper steering column and the lower steering column, and is used to control the mechanical connection and decoupling between the upper steering column and the lower steering column; when the electromagnetic clutch is engaged, the mechanical connection between the upper steering column and the lower steering column is controlled, and when the electromagnetic clutch is disengaged, the decoupling between the upper steering column and the lower steering column is controlled; The return and road sense motor is installed on the upper steering column, and is used to provide steering return torque and road sense feedback; The electro-hydraulic steering assist mechanism is connected to the lower steering column, and the electro-hydraulic steering assist mechanism is used to provide assistance for wheel steering; The steering link is connected to the electro-hydraulic steering assist mechanism and the wheels, and the steering link is used to transmit the steering torque to the wheels.

7. The control method of the commercial vehicle electronic power steering system according to claim 6, characterized in that: The driving modes include: driver driving mode, active control mode, chassis domain control mode, driver takeover mode and system electronic control failure mode; The control unit controls the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, and controls the working state of the return and road sensing motor and the electro-hydraulic steering assist mechanism, including: In the driver driving mode, the control unit controls the electromagnetic clutch to engage, the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism provides assistance; In the active control mode, the control unit controls the electromagnetic clutch to disengage, cutting off the mechanical connection between the upper steering column and the lower steering column; the electro-hydraulic steering assist mechanism independently controls the steering of the wheels; the return and road sense motor provides road sense feedback; In the chassis domain control mode, when the control unit detects the split road condition, it controls the electromagnetic clutch to disengage and cuts off the mechanical connection between the upper steering column and the lower steering column; the electro-hydraulic steering assist mechanism actively adjusts the steering angle of the wheel according to the vehicle driving state to maintain the vehicle direction stability; In the driver takeover mode, when the control unit detects that the driver actively turns the steering wheel and the steering angle of the steering wheel exceeds a set threshold, the control unit controls the electromagnetic clutch to be converted from a disengaged state to an engaged state, and restores the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism provides assistance according to the driver's operating intention to achieve the driver's target angle and ensure smooth switching from the active control mode or the chassis domain control mode to the driver driving mode; In the electronic control failure mode, the electromagnetic clutch automatically maintains the engagement state under the action of the mechanical spring mechanism to maintain the mechanical connection between the upper steering column and the lower steering column, so that the driver's steering torque is transmitted to the lower steering column through the mechanical connection; the electro-hydraulic steering assist mechanism provides basic hydraulic assistance to ensure emergency steering capability.

8. The control method of the commercial vehicle electronically controlled power steering system according to claim 7, characterized in that: The method further comprises: In active control mode, chassis domain control mode and driver takeover mode, the return and road sense motor provides road sense feedback and assists the driver's steering operation, providing necessary steering torque support; In the driver driving mode and the electronic control system failure mode, the return and road sensing motors stop working, and the steering system maintains basic functions through mechanical connection and hydraulic assistance.

9. The control method of the commercial vehicle electronic power steering system according to claim 7, characterized in that: The commercial vehicle electronically controlled power steering system further includes a steering angle sensor; The method further comprises: The steering angle sensor monitors the steering angle of the upper steering column in real time, and feeds back the steering angle of the upper steering column to the control unit; The control unit determines the driver's intention to take over and the switching of the control mode according to the steering angle of the upper steering column.

10. The control method of the commercial vehicle electronic power steering system according to any one of claims 7 to 9, characterized in that: The control unit controls the engagement and disengagement of the electromagnetic clutch according to the vehicle driving state and driving mode, including: In the active control mode, the chassis domain control mode or the driver takeover mode, the control unit outputs an electric control signal to the electromagnetic clutch; In the driver driving mode or the electronic control failure mode, the control unit does not output an electronic control signal to the electromagnetic clutch; If the electromagnetic clutch receives the electric control signal output by the control unit, the electromagnetic clutch is in a disengaged state in response to the electric control signal to cut off the mechanical connection between the upper steering column and the lower steering column; Otherwise, the electromagnetic clutch is in an engaged state to maintain the mechanical connection between the upper steering column and the lower steering column through its own spring mechanism; In the electronically controlled failure mode, the electromagnetic clutch automatically maintains the engaged state under the action of the mechanical spring mechanism.

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