Methods for operating and / or affecting a steering system, a steering system, and a vehicle including a steering system.

Abstract

The present invention provides a method for influencing a steering system to operate a steer-by-wire steering system, and a steering system itself. [Solution] An external first target characteristic quantity characterizes the target operating position of a steering actuator; a target position for a steering element of an input device depending on the external first target characteristic quantity, wherein a drive signal to the actuator of the input device that affects the actual position of the steering element depending on the target position and actual position of the steering element, a second target characteristic quantity characterizes the target operating position of the steering actuator depending on the actual position of the steering element, and a limited target characteristic quantity depending on the external first target characteristic quantity and the second target characteristic quantity, wherein the limited target characteristic quantity is limited by at least one predetermined limit value, and the target operating position for the steering actuator is determined depending on the second target characteristic quantity and the limited target characteristic quantity.

Description

Technical Field

[0001] Prior Art The present invention relates to a method for operating a steering system and / or for influencing a steering system, a steering system, and a vehicle including the steering system.

Background Art

[0002] In assisted driving at, for example, SAE L1, SAE L2, or SAE L2+ levels according to SAE J3016, using a steering system, particularly a steer-by-wire type steering system, a vehicle detects a target trajectory and determines corresponding target positions for, for example, the steering angle, the actual steering angle, and / or the rack position of the rack actuator of the steering system in order to achieve this target trajectory. In the case of the assisted operation mode of the vehicle, the steering system recognizes changes in the target position in cooperation with the driver of the vehicle or the user of the steering system, or, in the case of the autonomous operation mode of the vehicle or during autonomous driving, recognizes changes in the target position independently of the driver. Autonomous driving should be associated with, for example, SAE L3 level or higher according to SAE J3016, and assisted driving should be associated with, for example, SAE levels below SAE L3. For example, in the case of assisted driving at SAE L2 or SAE L1, the driver's input must have a higher priority than the target trajectory specified by the vehicle.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Therefore, a steering system is desired that enables precise adjustment of the steering angle and provides reliable feedback to the driver or user, for example, via the movement of the steering wheel that characterizes the corresponding current steering angle. Furthermore, it is required to provide precise intervention means for the driver or user.

Means for Solving the Problems

[0004] Disclosure of the Invention This is achieved by the method described in the independent claim, a steering system, and a vehicle including the steering system.

[0005] A method for operating a steering system, particularly a steer-by-wire steering system, and / or for influencing a steering system, particularly a steer-by-wire steering system, is to provide, for example by a control device, an external first target characteristic quantity that characterizes the target operating position of a steering actuator, particularly a rack actuator, and to determine a target position for a steering element of an input device, depending on the external first target characteristic quantity, wherein the steering element is an interface between the user of the steering system and the steering system, such as a steering wheel, and the actual position of the steering element can be influenced by the user. The method includes: identifying a drive signal to an actuator of an input device that affects the actual position of a steering element, depending on the target position and actual position of the steering element; identifying a second target characteristic quantity that characterizes the target operating position of a steering actuator, depending on the actual position of the steering element; identifying a limited target characteristic quantity, depending on a first external target characteristic quantity and the second target characteristic quantity, wherein the limited target characteristic quantity is limited by at least one predetermined limit value; and identifying a target operating position for the steering actuator, depending on the second target characteristic quantity and the limited target characteristic quantity. By identifying the target operating position of the steering actuator depending on a first external target characteristic quantity, the first external target characteristic quantity has a direct influence on the steering actuator, thereby enabling the steering actuator to be adjusted accurately and quickly in accordance with the specification by the target characteristic quantity. Furthermore, the steering feel of the steering element perceived by the user can be arbitrarily assigned, independent of the influence of the steering actuator and / or chassis system. Furthermore, only a single interface is required between the steering actuator and the input device, thereby ensuring a high safety standard for the steering system.

[0006] When identifying a limited target characteristic, it may be assumed that a second target characteristic is subtracted from an external first target characteristic, and that the result of this subtraction is limited by at least one constraint value. This improves the efficiency of the method and reduces the complexity of its implementation.

[0007] When determining the target operation position, it can be assumed that a second target characteristic and a limited target characteristic are added together. This improves the efficiency of the method and reduces the complexity of implementation.

[0008] In one example, the method includes identifying a drive signal for a steering actuator depending on the target operating position and the actual operating position of the steering actuator, wherein the drive signal specifically characterizes the drive torque for the actuator.

[0009] A steering system, particularly a steer-by-wire steering system, includes a steering actuator and an input device including a steering element, wherein the steering system is configured to: identify a target position for the steering element of the input device, depending on an external first target characteristic quantity, provided, for example by a control device, that characterizes the target operating position of the steering actuator, particularly a rack actuator, wherein the steering element is an interface between the user of the steering system and the steering system, such as a steering wheel, which can be influenced by the user's actual position of the steering element; identify a drive signal to the actuator of the input device that influences the actual position of the steering element, depending on the target position and the actual position of the steering element; identify a second target characteristic quantity, characterizing the target operating position of the steering actuator, depending on the actual position of the steering element; identify a limited target characteristic quantity, depending on the external first target characteristic quantity and the second target characteristic quantity, wherein the limited target characteristic quantity is limited by at least one predetermined limit value; and identify a target operating position for the steering actuator, depending on the second target characteristic quantity and the limited target characteristic quantity.

[0010] It may be assumed that the steering system is configured to subtract a second target characteristic quantity from an external first target characteristic quantity when identifying a limited target characteristic quantity, and to limit the result of this subtraction using at least one limiting value.

[0011] It can be assumed that the steering system is configured to add a second target characteristic quantity and a limited target characteristic quantity when determining the target operating position.

[0012] It may be assumed that the steering system is configured to identify a drive signal to the steering actuator, depending on the target operating position and the actual operating position of the steering actuator, and that the drive signal specifically characterizes the drive torque for the actuator.

[0013] The vehicle includes a steering system according to the above embodiment, the steering system being configured to influence the trajectory of the vehicle by particularly implementing the method according to the above embodiment and in particular by operating at least one wheel of the vehicle, the at least one wheel being operationally connected to a steering actuator, for example, via a rack.

[0014] Further embodiments will become apparent from the drawings and the following description. [Brief explanation of the drawing]

[0015] [Figure 1] This is a block circuit diagram of the steering system. [Figure 2] This figure shows methods for operating and / or affecting the steering system. [Figure 3] This is a schematic diagram of the vehicle, including the steering system. [Figure 4] This figure shows the temporal changes of the characteristic variables of the steering system. [Figure 5]This figure shows the temporal changes of the characteristic variables of the steering system. [Modes for carrying out the invention]

[0016] Figure 1 shows a schematic diagram of the steering system 100. The steering system 100 is configured, for example, as a steer-by-wire steering system and is used to control the vehicle. The steering system 100 includes a steering actuator 106 and an input device 112 including a control element 110. The control element 110 may be configured as a handle for operation by the user of the steering system 100. The control element 110 may be, for example, a steering handle, a steering wheel, or a joystick. The control element 110 forms an interface between the user and the steering system 100, thereby allowing the user to make inputs to the steering system 100, such as steering specifications for controlling the vehicle.

[0017] The steering system 100 is configured to determine a target position 108 relative to the steering element 110 of the input device 112, depending on a provided external first target characteristic quantity 102 that characterizes the target operating position 104 of the steering actuator 106. The provided external first target characteristic quantity 102 may be provided, for example, by a vehicle control device 304 (Figure 3) including the steering system 100. The control device 304 may be provided, for example, distributed relative to the steering system 100. The external first target characteristic quantity 102 is read or retrieved by the steering system 100 and subsequently processed further. The external first target characteristic quantity 102 characterizes, for example, a target trajectory of the vehicle, as identified by the control device within the framework of an application of assisted driving or autonomous driving of the vehicle. This target trajectory is achieved, for example, by the corresponding target operating position 104 of the steering actuator 106.

[0018] The target position 108 is, for example, the rotational angle of the operating element 110, and reflects the current position of the steering actuator 106 in a recognizable manner for the user. The steering actuator 106 is configured, for example, as a rack actuator.

[0019] The steering system 100 is configured to specify a drive signal 116 for the actuator 118 of the input device 112 that affects the actual position 114 of the operating element 110, based on the target position 108 and the actual position 114 of the operating element 110. Thus, it is possible to affect the actual position 114 by the actuator and the user. The drive signal 116 may be specified, for example, by a position adjustment unit 136.

[0020] The steering system 100 is configured to specify a second target characteristic quantity 120 that characterizes the target operating position 104 of the steering actuator 106, depending on the actual position 114 of the operating element 110. The target operating quantity 104 of the steering actuator 106 is affected by an external first target characteristic quantity 102 and / or a second target characteristic quantity 120 in the steering system 100 according to the present invention. In this case, the external first target characteristic quantity reflects, for example, the influence by the application of assisted driving or autonomous driving, and the second characteristic quantity reflects the influence by the user, for example, a steering input.

[0021] The steering system 100 is configured to specify a limited target characteristic quantity 122, depending on the external first target characteristic quantity 102 and the second target characteristic quantity 120, and the limited target characteristic quantity 122 is limited by at least one predetermined limit value 124. The at least one predetermined limit value 124 may be applied, for example, to achieve a desired steering behavior.

[0022] The steering system 100 is configured to specify a target operating position 104 for the steering actuator 106 depending on a second target characteristic quantity 120 and a limited target characteristic quantity 122. Thereby, when specifying the target operating position 104 of the steering actuator 106, the influence by the user is considered via the second target characteristic quantity 120, and the influence by an application related to, for example, assisted driving or autonomous driving is considered via an external first target characteristic quantity 102, and the desired steering characteristics of the steering system 100 are considered via at least one predetermined limit value 124. By specifying in this way, it becomes possible to substantially directly influence by the external first target characteristic quantity 102 via the bypass 138.

[0023] It may be assumed that the steering system 100 is configured to subtract the second target characteristic quantity 120 from the external first target characteristic quantity 102 when specifying the limited target characteristic quantity 122, and limit the result of the subtraction using at least one limit value 124. The at least one limit value 124 acts, for example, so that the limited target characteristic quantity 122 varies within a range defined by the at least one limit value 124. Therefore, the limited target characteristic quantity 122 can, for example, at most take on the value of at least one predetermined limit value 124. The at least one predetermined limit value 124 may be, for example, + / -1 mm.

[0024] It may be assumed that the steering system 100 is configured to add the second target characteristic quantity 120 and the limited target characteristic quantity 122 when specifying the target operating position 104.

[0025] The steering system 100 is configured to determine a drive signal 128 for the actuator 130 of the steering actuator 106, depending on the target operating position 104 and the actual operating position 126 of the steering actuator 106, and the drive signal 128 may be assumed to characterize the drive torque for the actuator 130 in particular. The actuator 130 may be, for example, an electrically driven unit. The steering actuator 106 may be configured as a rack actuator and may include a rack 132. In this case, the target operating position 104 and the actual position 126 may characterize, for example, the position of the rack, in particular in millimeters.

[0026] At least one limit value 124 can, for example, influence the dynamics between an external first target characteristic quantity 102 and the actual operating position 126 or target operating position 104, particularly the tracking behavior. Furthermore, at least one limit value 124 can influence the delay between, for example, a user's steering input that affects the actual position 114 of the steering element 110 and the corresponding action of the target operating position 104 or actual operating position 126. At least one limit value 124 may be specified variably, for example, depending on the vehicle's motion state and / or a selected operating mode of the vehicle, or it may be applied as a constant parameter.

[0027] Figure 2 shows a flowchart of a method 200 for operating a steering system 100, for example, a steer-by-wire steering system, and / or for influencing a steering system 100, for example, a steer-by-wire steering system. The method includes providing an external first target characteristic quantity 102 that characterizes a target operating position 104 of a steering actuator 106, and, depending on the external first target characteristic quantity 102, identifying a target position 108 for a steering element 110 of an input device 112, the steering element 110 being an interface between the user of the steering system 100 and the steering system 100, and the user being able to influence the actual position 114 of the steering element 110. The method 200 may be used, for example, in assisted driving or autonomous driving, to operate a steering system 100 and / or to influence a steering system 100. Method 200 may be used, for example, as a general interface for operating the steering system 100, regardless of the operating state of the vehicle including the steering system 100.

[0028] Method 200 includes identifying a drive signal 116 for an actuator 118 of an input device 112 that affects the actual position 114 of the control element 110, depending on the target position 108 and the actual position 114 of the control element 110.

[0029] Method 200 includes identifying a second target characteristic quantity 120 that characterizes a target operating position 104 of the steering actuator 106, depending on the actual position 114 of the steering element 110 208, and identifying a limited target characteristic quantity 122, depending on an external first target characteristic quantity 102 and the second target characteristic quantity 120, wherein the limited target characteristic quantity 122 is limited by at least one predetermined limit value 124.

[0030] Method 200 includes determining a target operating position 104 for the steering actuator 106, depending on a second target characteristic quantity 120 and a limited target characteristic quantity 122.

[0031] When identifying a limited target characteristic 122 210, it may be assumed that a second target characteristic 120 is subtracted from an external first target characteristic 102, and the result of this subtraction is limited by at least one limit value 124.

[0032] When identifying the target operating position 104 212, it can be assumed that the second target characteristic quantity 120 and the limited target characteristic quantity 122 are added together.

[0033] Method 200 may be assumed to include identifying a drive signal 128 for the actuator 130 of the steering actuator 106, depending on the target operating position 104 and the actual operating position 126 of the steering actuator 106, wherein the drive signal 128 particularly characterizes the drive torque for the actuator 130.

[0034] It is assumed that several of the above steps of Method 200 may be performed simultaneously.

[0035] Figure 3 shows a vehicle 300 including the steering system 100 according to the above embodiment, the steering system 100 is configured to implement the method 200 according to the above embodiment in particular, and to influence the trajectory of the vehicle 300 by operating at least one wheel 302 of the vehicle 300, the at least one wheel 302 being operationally connected to a steering actuator 106, for example via a rack 132.

[0036] Figure 4 shows the transition of a characteristic quantity of the steering system 100 in the form of position 4 over time 2. Figure 4 shows the behavior of the steering system 100 in an example where there is no user intervention or input. The transition of the external first target characteristic quantity 102 indicates that a change in the actual operating position 126 is desired. The target operating position 104 directly follows the external first target characteristic quantity 102, and as a result, the actual operating position 126 also directly follows the external first target characteristic quantity 102, taking into account the internal inertia of the steering system 100. Similarly, the position of the steering element 110 also follows the external first target characteristic quantity 102 due to its internal inertia, as reflected based on the second target characteristic quantity 120 shown in the transition. The target operating position 104 directly follows the external first target characteristic variable 102 until, at the time of identification 212, the external first target characteristic variable 102 is limited by the target characteristic variable 122, which is limited by at least one predetermined limit value 124. In the illustrated example, the target operating position 104 no longer has the same dynamics as the external first target characteristic variable 102 from the limit, and follows the dynamics of the second target characteristic variable 120.

[0037] Figure 5 shows the transition of a characteristic variable of the steering system 100 in the form of a position 4 over time 2. In the example illustrated in Figure 5, there is a user intervention that can be recognized based on the transition of a second target characteristic variable 120. This input has no effect on the target operation signal 104 based on at least one limit value 124, and as a result, the actual operation signal 126 also does not change. This results in a delay between the user input in the form of the second target characteristic variable 120 and the corresponding change in the target operation position 104, and this delay can be adjusted by at least one limit value 124. This delay persists until the limited target characteristic variable 122 exceeds at least one predetermined limit value 124.

Claims

1. A steering system (100), particularly a steer-by-wire steering system, and / or a method (200) for influencing a steering system (100), particularly a steer-by-wire steering system, The above method (200) is, - To provide (202) an external first target characteristic quantity (102) that characterizes the target operating position (104) of the steering actuator (106), - Depending on the external first target characteristic quantity (102), a target position (108) for the steering element (110) of the input device (112) is identified (204), wherein the steering element (110) is an interface between the user of the steering system (100) and the steering system (100), and the user can influence the actual position (114) of the steering element (110), - Identifying (206) a drive signal (116) for the actuator (118) of the input device (112) that affects the actual position (114) of the control element (110), depending on the target position (116) and the actual position (114) of the control element (110), - Identifying (208) a second target characteristic quantity (120) that characterizes the target operating position (104) of the steering actuator (106) depending on the actual position (114) of the steering element (110), - Identifying a limited target characteristic (122) (210) depending on the external first target characteristic (102) and the second target characteristic (120), wherein the limited target characteristic (122) is limited by at least one predetermined limit value (124), - Depending on the second target characteristic quantity (120) and the limited target characteristic quantity (122), the target operating position (104) for the steering actuator (106) is determined (212), Method (200), including.

2. In identifying the limited target characteristic (122) (210), the second target characteristic (120) is subtracted from the external first target characteristic (102), and the result of the subtraction is limited using the at least one limit value (124). The method according to claim 1 (200).

3. When identifying the target operating position (104) (212), the second target characteristic quantity (120) and the limited target characteristic quantity (122) are added together. The method according to claim 1 or 2 (200).

4. The above method (200) is, - Identifying (214) a drive signal (128) for the actuator (130) of the steering actuator (106) depending on the target operating position (104) and the actual operating position (126) of the steering actuator (106), wherein the drive signal (128) particularly characterizes the drive torque for the actuator (130). including, The method according to any one of claims 1 to 3 (200).

5. A steering system (100), in particular a steer-by-wire type steering system, The steering system (100) is Steering actuator (106) and An input device (112) including a control element (110), Includes, The steering system (110) is - For example, depending on an external first target characteristic quantity (102) provided by the control device (304) that characterizes the target operating position (104) of the steering actuator (106), the target position (108) for the steering element (110) of the input device (112) is identified (204), wherein the steering element (110) is an interface between the user of the steering system (100) and the steering system (100), and the actual position (114) of the steering element (110) can be influenced by the user. - Identifying (206) a drive signal (116) for the actuator (118) of the input device (112) that affects the actual position (114) of the control element (110), depending on the target position (108) and the actual position (114) of the control element (110), - Identifying (208) a second target characteristic quantity (120) that characterizes the target operating position (104) of the steering actuator (106) depending on the actual position (114) of the steering element (110), - Identifying a limited target characteristic (122) (210) depending on the external first target characteristic (102) and the second target characteristic (120), wherein the limited target characteristic (122) is limited by at least one predetermined limit value (124), - Depending on the second target characteristic quantity (120) and the limited target characteristic quantity (122), the target operating position (104) for the steering actuator (106) is determined (212), A steering system (100) configured to perform the following.

6. The steering system (100) is In identifying the limited target characteristic (122) (210), the second target characteristic (120) is subtracted from the external first target characteristic (102), and the result of the subtraction is limited using the at least one limit value (124). It is structured in such a way. The steering system (100) according to claim 5.

7. The steering system (100) is When identifying the target operating position (104) (212), the second target characteristic quantity (120) and the limited target characteristic quantity (122) are added together. It is structured in such a way. The steering system (100) according to claim 5 or 6.

8. The steering system (100) is The method involves determining (214) a drive signal (128) for the actuator (130) of the steering actuator (106) depending on the target operating position (104) and the actual operating position (126) of the steering actuator (106), wherein the drive signal (128) particularly characterizes the drive torque for the actuator (130). It is configured to implement A steering system (100) according to any one of claims 5 to 7.

9. A vehicle (300) comprising a steering system (100) according to any one of claims 5 to 8, The steering system (100) is configured to influence the trajectory of the vehicle, in particular by implementing the method (200) according to any one of claims 1 to 4, and in particular by operating at least one wheel (302) of the vehicle. A vehicle (300) in which at least one wheel (302) is operationally connected to the steering actuator (106) via, for example, a rack (132).

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