Steering system

Abstract

A method for steering the steering wheels of a vehicle, the method comprising the steps of applying a first torque to the steering column of the vehicle using a first motor; determining whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column; applying a torque greater than the predetermined torque to the steering column using at least one first motor and / or applying torque to the steering column using a second motor.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 971,379, filed on February 7, 2020, the subject matter of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a steering system for turning the steering wheels of a vehicle, and more particularly, to a steering system for turning the steering wheels in response to rotation of the vehicle's steering wheel and / or autonomously. Background Technology

[0004] Commercial vehicle steering systems do not support autonomous steering without a driver / operator. The vehicle operator determines the impact of any malfunctions related to the steering system and takes control of the vehicle's steering in the event of a malfunction. Therefore, an operator is essential for the safe operation of the vehicle. If the hydraulic fluid flowing to the hydraulic steering gear fails or decreases, or if there is any mechanical connection failure that increases the steering force required to actuate the steering gear, the increased steering force must be detected by the vehicle operator. Summary of the Invention

[0005] This invention provides a method for steering the steering wheels of a vehicle, the method comprising applying a first torque to the steering column of the vehicle using a first motor; determining whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column; applying a torque greater than the predetermined torque to the steering column using the first motor and / or applying torque to the steering column using a second motor.

[0006] According to another aspect of the invention, determining whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column includes the following steps: comparing at least one of the following parameters with at least one expected parameter: the torque applied by the first motor, the expected torque to be applied to the steering column by the first motor, the torque applied to the steering column, the rotational speed of the steering column, the rotational acceleration of the steering column, the current supplied to the first motor, the vehicle speed, and the tilt angle of the steering column, in order to determine whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column.

[0007] According to another aspect of the invention, determining whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column includes the following steps: comparing at least one of the parameters such as vehicle speed, steering column tilt angle, and vehicle yaw rate with at least one expected parameter in order to determine whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column.

[0008] According to another aspect of the invention, determining whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column includes the following steps: comparing at least one of the parameters of the temperature of the fluid flowing through the steering gear, the flow rate of the fluid flowing to the steering gear, and the pressure of the fluid flowing to the steering gear with at least one expected parameter in order to determine whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column.

[0009] According to another aspect of the invention, determining whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column further includes the following steps: comparing the parameters such as the torque applied by the first motor, the expected torque to be applied by the first motor to the steering column, the torque applied to the steering column, the rotational speed of the steering column, the rotational acceleration of the steering column, the current supplied to the first motor, the vehicle speed, the tilt angle of the steering column, the yaw rate of the vehicle, the temperature of the fluid flowing through the steering gear, the flow rate of the fluid flowing to the steering gear, and the pressure of the fluid flowing to the steering gear with the expected parameters in order to determine whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column. Attached Figure Description

[0010] By referring to the following description and accompanying drawings, those skilled in the art will appreciate the above-mentioned and other features and advantages of the present invention, as illustrated in the drawings:

[0011] Figure 1 A steering system for turning steering wheels of a vehicle, constructed according to the present invention, is schematically shown.

[0012] Figure 2 schematically shown Figure 1 The control system of the steering system shown;

[0013] Figure 3 It shows Figure 1 and Figure 2 The control method of the steering system shown. Detailed Implementation

[0014] Figure 1 and Figure 2 A steering system 10 for turning the steering wheels 12, 14 is schematically shown. The steering system 10 can be driven by an operator / driver and / or autonomously. The steering system 10 includes a steering wheel or steering column 16 that can be rotated by the vehicle operator. The steering wheel 16 is connected to a steering gear 18 via a steering column 20. The steering gear 18 can be any conceivable steering gear, such as a hydraulically assisted integral steering gear or a rack and pinion steering gear.

[0015] The steering column 20 may include a steering wheel portion 22 connected to the steering wheel 16. A first intermediate portion 24 of the steering column may be connected to the steering wheel portion 22. A second intermediate portion 26 of the steering column 20 may be connected to the first intermediate portion 24 and the input shaft 28 of the steering gear 18. The steering wheel portion 22, the first intermediate portion 24, the second intermediate portion 26, and the input shaft 28 of the steering gear may be interconnected via universal joints. Although the steering column 20 shown in the figure has a steering wheel portion 22, a first intermediate portion 24, and a second intermediate portion 26, it is conceivable that the steering column may have any conceivable configuration.

[0016] When the steering wheel 16 is rotated, rotational force is transmitted to the steering gear 18 through the steering column 20. The rotational force operates the steering gear 18. When the steering gear 18 is operated, the steering gear rotates the steering wheels 12 and 14 in a known manner via the steering linkage.

[0017] The steering system 10 includes a first control component 30, which is operatively connected to the steering column 20 at a first position, which may be located near the steering wheel 16. The first control component 30 may be connected to a first intermediate portion 24 of the steering column 20. Although the first control component 30 is shown connected to the first intermediate portion 24, it is conceivable that the first control component 30 may be connected to any desired location on the steering column 20.

[0018] The first control assembly 30 includes at least a first sensor 32, a reversible first motor 34, and a first electronic control unit (ECU) 36. The first sensor 32 can detect the torque applied to the steering column 20 and / or the angular position of the steering column. The first control assembly 30 can be integrated into a single unit through which a first intermediate portion 24 of the steering column 20 passes.

[0019] The first torque / position sensor 32, which is operable by the first control component 30, can detect the applied torque and angular displacement of the steering wheel 16. The first torque / position sensor 32 also generates signals representing the applied torque and angular displacement of the steering wheel 16. The first torque / position sensor 32 can be any known sensor or sensor group used to detect the applied torque and angular displacement of the steering wheel 16 and generate signals representing the detected parameters.

[0020] A first motor 34 is operatively connected to a first intermediate portion 24 of the steering column 20. The output of the first motor 34 is connected to the steering column 20 in a known manner via a gear assembly. When driven, the first motor 34 applies torque to the steering column 20.

[0021] The first electronic control unit 36 ​​is operatively connected to the first torque / position sensor 32 and the first motor 34. The first electronic control unit 36 ​​can receive signals from the first torque / position sensor 32 representing the applied torque and angular displacement of the steering wheel 16. The first electronic control unit 36 ​​can also receive signals representing vehicle speed, lateral acceleration, and / or other vehicle-related operating conditions. In response to the signals from the first torque / position sensor 32, the first electronic control unit 36 ​​can drive the first motor 34 to apply torque to the steering column 20. The first motor 34 can be operated to assist rotation of the first center section 24 and the steering wheel 16. The first motor 34 can also be operated to resist rotation of the first center section 24 and the steering wheel 16 to provide a "feel" to the operator rotating the steering wheel. When the vehicle operator steers the vehicle, the first electronic control unit 36 ​​can operate the first motor 34 to either assist or resist rotation of the steering column 20 depending on the vehicle operating conditions. Therefore, the first control component 30 can apply the required rotational force to the first center section 24 of the steering column 20 to provide the required output torque through the steering column.

[0022] The second control component 40 is operatively connected to the steering column 20 at a location adjacent to the steering gear 18. The second control component 40 can be connected to the input shaft 28 of the steering gear 18. Although the second control component 40 shown in the figure is connected to the input shaft 28, it is conceivable that the second control component can be connected to any desired location on the steering column 20.

[0023] The second control assembly 40 is substantially similar to the first control assembly 30, and includes at least a second sensor 42, a reversible second motor 44, and a second electronic control unit 46. The second sensor 42 can detect the torque applied to the steering column 20 and / or the angular position of the steering column. The second control assembly 40 can be integrated into a single unit through which the input shaft 28 of the steering gear 18 passes.

[0024] The second torque / position sensor 42, which is operable by the second control component 40, can detect the applied torque and angular displacement of the input shaft 28. The second torque / position sensor 42 also generates signals representing the applied torque and angular displacement of the input shaft 28. The second torque / position sensor 42 can be any known sensor or sensor group used to detect the applied torque and angular displacement of the input shaft 28 and generate signals representing the detected parameters.

[0025] The second motor 44 is operatively connected to the input shaft 28 of the steering gear 18. The output component of the second motor 44 can be connected to the steering column 20 in a known manner via a gear assembly. When driven, the second motor 44 applies torque to the steering column 20.

[0026] The second electronic control unit 46 is operatively connected to the second torque / position sensor 42 and the second motor 44. The second electronic control unit 46 can receive signals from the second torque / position sensor 42 indicating the applied torque and angular displacement of the input shaft 28. The second electronic control unit 46 can also receive signals indicating vehicle speed, lateral acceleration, and / or other vehicle-related operating conditions. In response to the signals from the second torque / position sensor 42, the second electronic control unit 46 can drive the second motor 44 to apply torque to the steering column 20 and the steering gear 18. The second motor 44 can be operated to assist rotation of the input shaft 28. The second motor 44 can also be operated to impede rotation of the input shaft 28. When the vehicle operator steers the vehicle, the second electronic control unit 46 can operate the second motor 44 to either assist or impede rotation of the steering column depending on the vehicle operating conditions. Therefore, the second control assembly 40 can apply the required rotational force to the input shaft 28 of the steering gear 18 and / or the second intermediate portion 26 of the steering column 20 to provide the required output torque through the steering column.

[0027] Vehicle main controller 50 ( Figure 2 The vehicle controller 50 can communicate with the first control component 30 and the second control component 40 via communication channels, such as a controller area network (CAN) or any other required communication network. The vehicle controller 50 may have a first electronic control unit 52 and a second electronic control unit 54 that communicate with each other. The first electronic control unit 52 and the second electronic control unit 54 can communicate with the first control component 30 and the second control component 40 via the vehicle controller's first communication channel 56 and second communication channel 58, and the vehicle communication bus 60. The first control component 30 can communicate with the vehicle communication bus 60 via its first communication channel 62. The second control component 40 can communicate directly with the vehicle controller 50 via its first communication channel 64. The first control component 30 and the second control component 40 can communicate directly with each other via the second communication channel 66 of the first control component 30 and the second communication channel 68 of the second control component 40. The second communication channels 66 and 68 can only communicate with each other. Therefore, the first control component 30 and the second control component 40 communicate with each other through their dedicated communication channels.

[0028] The vehicle controller 50 can send signals to the electronic control unit 36 ​​of the first control component 30 and the electronic control unit 46 of the second control component 40 to operate the vehicle autonomously. The vehicle controller 50 drives at least one of the first control component 30 and the second control component 40 to rotate the steering column 20 and the steering wheels 12, 14, so that the vehicle can steer autonomously. It is conceivable that the vehicle controller 50 can simultaneously drive the first control component and the second control component to rotate the steering wheels 12, 14.

[0029] Vehicle controller 50 can send the same position command to first control component 30 and second control component 40 to establish a redundant system. First control component 30 and second control component 40 can communicate with each other to determine which control component will autonomously steer the vehicle. The other control component serves as a backup or redundant control component, and if one control component fails to steer the vehicle, the other control component will autonomously steer the vehicle. For example, the first electronic control unit 36 ​​of the first control component 30 and the second electronic control unit 46 of the second control component 40 can communicate with each other and determine that the second control component 40 will autonomously steer the vehicle. The second electronic control unit 46 of the second control component 40 receives a position signal or command from vehicle controller 50 to autonomously steer the vehicle. In response to the position signal from vehicle controller 50, the second electronic control unit 46 drives the second motor 44 to apply torque to the steering column 20 and actuate the steering gear 18 to turn the steering wheels 12, 14. The first electronic control unit 36 ​​of the first control component and the second electronic control unit 46 of the second control component 40 communicate to determine whether the first motor 34 needs to apply torque to the steering column 20. If it is determined that the first motor does not need to apply torque to the steering column 20, then the first electronic control unit 36 ​​of the first control assembly 30 does not drive the first motor 34. If it is determined that the first motor 34 needs to apply torque to the steering column 20, then in response to a position signal or command from the vehicle controller 50, the first electronic control unit 36 ​​drives the first motor 34 to apply torque to the steering column 20. Therefore, the first control assembly 30 serves as a backup control assembly for the second control assembly 40. If the second control assembly 40 fails, then the first control assembly 30 can autonomously rotate the steering column 20 and the steering wheels 12, 14 in response to signals received from the vehicle controller 50.

[0030] If communication from the vehicle controller 50 to the second control component 40 fails, the signal from the vehicle controller can be transmitted to the second control component 40 via the first electronic control unit 36 ​​of the first control component 30. Therefore, the second control component 40 can continue to apply torque to the steering column 20 and actuate the steering gear 18 to turn the steering wheels 12, 14.

[0031] Alternatively, the first control component 30 and the second control component 40 may communicate with each other and determine that the first control component 30 will cause the vehicle to steer autonomously. The first electronic control unit 36 ​​of the first control component 30 receives a position signal or command from the vehicle controller 50 to cause the vehicle to steer autonomously. In response to the position signal from the vehicle controller 50, the first electronic control unit 36 ​​drives the first motor 34 to apply torque to the steering column 20, thereby actuating the steering gear 18 and turning the steering wheels 12, 14. The second electronic control unit 46 of the second control component 40 communicates with the first electronic control unit 36 ​​of the first control component 30 to determine whether the second motor 44 needs to apply torque to the steering column 20. If it is determined that the second motor does not need to apply torque to the steering column 20, then the second electronic control unit 46 of the second control component 40 does not drive the second motor 44. If it is determined that the second motor needs to apply torque to the steering column 20, then the second electronic control unit 46 drives the second motor 44 to apply torque to the steering column 20. Therefore, the second control component 40 serves as a backup control component for the first control component 30. If the first control component 30 fails, the second control component 40 can autonomously rotate the steering column 20 and the steering wheels 12, 14 in response to a signal received from the vehicle controller 50.

[0032] If communication from the vehicle controller 50 to the first control component 30 fails, the signal from the vehicle controller can be transmitted to the first control component via the second electronic control unit 46 of the second control component 40. Therefore, the first control component 30 can continue to apply torque to the steering column 20 and actuate the steering gear 18 to turn the steering wheels 12, 14.

[0033] Each control component in the first control component 30 and the second control component 40 needs to know whether it is to function as a standalone unit or to be combined with other control components. If one of the control components in the first control component 30 and the second control component 40 is the only control component that operates to enable the vehicle to steer autonomously, then that control component only receives input commands related to operating that control component to steer the vehicle without assistance from the other control component. The other control component in the first control component 30 and the second control component 40 only receives commands related to operating that other control component as a redundant or backup control component. Therefore, the first control component 30 and the second control component 40 serve as a redundant system for controlling the autonomous steering of the vehicle. Furthermore, when the vehicle operator turns the steering wheel 16, at least one of the first control component and the second control component can provide steering assistance and / or steering feel.

[0034] The first electronic control unit 36 ​​of the first control assembly 30 and the second electronic control unit 46 of the second control assembly 40 can communicate with each other and share information to determine whether the sole control assembly in the first and second control assemblies is operating correctly in response to signals from the vehicle controller. If the sole control assembly in the first and second control assemblies 30 does not operate correctly, the other control assembly in the first and second control assemblies can rotate the steering column 20 and / or actuate the steering gear 18 to turn the steering wheels 12, 14 to autonomously operate the vehicle. It is also conceivable that if both the first and second control assemblies 30 and 40 are operating normally, they can work together to turn the steering wheels 12, 14.

[0035] The vehicle controller 50 can receive signals indicating vehicle-related operating conditions. The vehicle controller 50 analyzes these signals and determines whether at least one of the first motor 34 and the second motor 44 attempts to apply a torque greater than a predetermined torque to the steering column 20. Such an attempt to apply a torque greater than the predetermined torque to the steering column 20 indicates a hard steering condition. The predetermined torque may be the maximum torque that the first motor 34 and the second motor 44 are intended to apply to the steering column 20 and / or the steering gear 18 for safety reasons. If the vehicle controller 50 determines that a hard steering condition exists, it can generate a control signal to control at least one of the first control component 30 and the second control component 40 to alleviate the hard steering condition. The vehicle controller 50 may increase the torque applied by the motor that is attempting to apply a torque greater than the predetermined torque to the steering column 20 to a torque greater than the predetermined torque to alleviate the hard steering condition. Figure 3 At least one of the multiple control processes of the vehicle controller 50 is shown.

[0036] like Figure 3As shown, a portion of the vehicle controller 50, referred to as a torque / angle detector 80, can determine whether at least one of the first motor 34 of the first control assembly 30 and the second motor 44 of the second control assembly 40 attempts to apply a torque greater than a predetermined torque to the steering column 20. The torque / angle detector 80 can receive a motor torque signal 82, representing the torque applied by each of the first motor 34 of the first control assembly 30 and the second motor 44 of the second control assembly 40. The torque / angle detector 80 can receive a steering position torque command signal 84, representing the expected torque to be applied by the first motor 34 and the second motor 44. The torque / angle detector 80 can receive a steering column torque signal 86, representing the torque applied to the steering column. The steering column torque signal 86 can be provided by the torque / position sensor 32 of the first control assembly 30 and the torque / position sensor 42 of the second control assembly 40. The torque / angle detector 80 can receive a steering column speed signal 88, representing the rotational speed of the steering column 20. The torque / angle detector 80 receives a steering column acceleration signal 90, which represents the rotational acceleration of the steering column 20. The torque / angle detector 80 also receives a motor current signal 92, which represents the current supplied to the first motor 34 and the second motor 44. The torque / angle detector 80 receives a vehicle speed signal 94, representing the vehicle's speed. The torque / angle detector 80 receives a steering angle signal 96, representing the angle of the steering column 20. The torque / angle detector 80 compares signals 82 to 96 with expected parameters for autonomous vehicle steering to determine whether one of the control components 30 and 40 attempts to apply a torque greater than a predetermined torque. If one of the motors 34 and 44 attempts to apply a torque greater than a predetermined torque, it indicates a hard steering situation.

[0037] Another part of the vehicle controller 50, referred to as the vehicle detector 100, can also determine whether at least one of the first motor 34 of the first control component 30 and the second motor 44 of the second control component 40 attempts to apply a torque greater than a predetermined torque to the steering column 20. The vehicle detector 100 can receive a vehicle speed signal 94 representing the vehicle speed, and a steering angle signal 96 representing the angle of the steering column 20. The vehicle detector 100 can also receive a yaw rate signal 102 representing the vehicle yaw rate. The vehicle detector 100 can compare signals 94, 96, and 102 with expected parameters for autonomous vehicle steering to determine whether one of the control components of the first control component 30 and the second control component 40 attempts to apply a torque greater than a predetermined torque. If one of the first motor 34 and the second motor 44 attempts to apply a torque greater than a predetermined torque, it indicates that a hard steering condition exists.

[0038] Another part of the vehicle controller 50, referred to as steering detector 110, can also determine whether at least one of the first motor 34 of the first control component 30 and the second motor 44 of the second control component 40 attempts to apply a torque greater than a predetermined torque to the steering column 20. Steering detector 110 may receive a steering fluid temperature signal 112, representing the temperature of the hydraulic fluid flowing through the steering gear 18. Steering detector 110 may receive a steering fluid flow rate signal 114, representing the flow rate of the hydraulic fluid flowing to the steering gear 18. Steering detector 110 may receive a steering fluid pressure signal 116, representing the pressure of the hydraulic fluid flowing to the steering gear 18. Steering detector 110 may compare signals 112 to 116 with expected parameters for autonomous vehicle steering to determine whether one of the control components of the first control component 30 and the second control component 40 attempts to apply a torque greater than a predetermined torque. If one of the first motor 34 and the second motor 44 attempts to apply a torque greater than a predetermined torque, it indicates that a hard steering condition exists.

[0039] The torque / angle detector 80 can send a signal 120 to the hard steering determination module 130, which determines whether at least one of the first motor 34 and the second motor 44 is in a hard steering condition. The vehicle detector 100 can send a signal 122 to the hard steering determination module 130. The steering detector 110 can send a signal 124 to the hard steering determination module 130. The hard steering determination module 130 can use at least one of the torque / angle detector signal 120, the vehicle detector signal 122, and the steering detector signal 124 to determine whether at least one of the first motor 34 of the first control component 30 and the second motor 44 of the second control component 40 attempts to apply a torque greater than a predetermined torque to the steering column 20. It is conceivable that the hard steering determination module 130 can use any combination of the torque / angle detector signal 120, the vehicle detector signal 122, and the steering detector signal 124 to determine whether at least one of the first motor 34 and the second motor 44 attempts to apply a torque greater than a predetermined torque to the steering column 20.

[0040] The hard steering determination module 130 can send a signal 132 indicating a hard steering situation to an external vehicle controller and / or vehicle operator. The hard steering determination module 130 can also send signal 132 to at least one of the first control component 30 and the second control component 40 to increase the torque applied by at least one of the first motor 34 and the second motor 44 to a torque greater than a predetermined torque. Therefore, if the steering system 10 detects that one of the first motor 34 of the first control component 30 and the second motor 44 of the second control component 40 is attempting to apply a torque greater than a predetermined torque, then the steering system 10 can increase the torque applied by said one of the first and second motors to a torque greater than a predetermined torque and / or increase the torque applied by the other of the first and second motors to alleviate the hard steering situation. If only one of the first motor 34 and the second motor 44 is attempting to apply a torque greater than a predetermined torque, then the hard steering determination module 130 can send a signal to the other control component of the first and second control components to cause the other motor to apply torque to assist the motor attempting to apply a torque greater than a predetermined torque.

[0041] The above description represents embodiments of the present invention. Of course, in order to describe the present invention, it is impossible to describe every possible combination of components and methods, but those skilled in the art will recognize that many further combinations and arrangements exist. Therefore, the present invention includes all such changes, modifications, and variations that fall within the scope and description of the following claims.

Claims

1. A method for steering the steering wheels of a vehicle, the method comprising the following steps: The first motor applies a first torque to the vehicle's steering column; Determine whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column; as well as At least one of the following two torques is applied: a torque greater than the predetermined torque applied to the steering column using the first motor; or a torque applied to the steering column using the second motor, wherein... The step of determining whether the first motor attempts to apply a torque greater than a predetermined torque to the steering column includes the following steps: The parameters are compared with the expected parameters to determine whether the first motor attempts to apply a torque greater than the predetermined torque to the steering column. These parameters include the torque applied by the first motor, the expected torque to be applied by the first motor to the steering column, the torque applied to the steering column, the rotational speed of the steering column, the rotational acceleration of the steering column, the current supplied to the first motor, the vehicle speed, the tilt angle of the steering column, the yaw rate of the vehicle, the temperature of the fluid flowing through the steering gear, the flow rate of the fluid flowing to the steering gear, and the pressure of the fluid flowing to the steering gear.

2. The method for steering the steering wheels of a vehicle according to claim 1, wherein, The first control component includes the first motor and the second control component includes the second motor; The vehicle controller communicates with the first control component and the second control component to enable the vehicle to steer autonomously; The second control component communicates directly with the first control component.

3. The method for steering the steering wheels of a vehicle according to claim 2, further comprising the following steps: The vehicle controller sends signals to the first control component and the second control component to enable the vehicle to steer autonomously; The first motor and the second motor are used in response to a signal from the vehicle controller to apply torque to the steering column so as to actuate the steering gear and turn the steering wheels; The first control component and the second control component communicate with each other to determine which control component should enable the vehicle to steer autonomously.

4. The method for steering the steering wheels of a vehicle according to claim 3, wherein, The second control component communicates with the first control component to determine whether the second motor needs to apply torque to the steering column, wherein the second motor of the second control component applies torque to the steering column.

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