Steering system, vehicle comprising the steering system, method for operating the steering system

Abstract

Steering system (102), vehicle (100) comprising the steering system (102), method for operating a steering system (102) of the vehicle (100), wherein the steering system (102) comprises an operating element (104) for detecting a rotation angle and a torque, wherein the steering system (102) comprises a steering actuator (104) for moving steered wheels (108) of the vehicle (100) depending on a target steering angle, wherein it is determined (204) whether the rotation angle lies in a first angular range or a second angular range different from the first angular range, wherein the target steering angle is determined in the first angular range of the rotation angle depending on the rotation angle (206), wherein the target steering angle is determined in the second angular range of the rotation angle depending on the torque (208), wherein the first angular range comprises the rotation angle that is assigned to the target steering angle for straight-ahead travel of the vehicle (100), wherein the second angular range comprises a rotation angle includes,which is assigned to a desired steering angle for a maximum turning angle of the steered wheels (108).

Description

State of the art

[0001] The invention is based on a steering system, a vehicle comprising the steering system, and a method for operating the steering system.

[0002] Such a steering system can be operated by a driver using a control element. The control element can be used to provide the driver with feedback. Disclosure of the invention

[0003] By means of the steering system and the method for operating the steering system of a vehicle according to the independent claims, driver feedback is output via an operating element of the steering system, which is effective even when the available angular range of the operating element is small.

[0004] The method provides that the steering system comprises an operating element for detecting a rotation angle, wherein a torque provided by the operating element is detected or provided, wherein the steering system comprises a steering actuator for moving steered wheels of the vehicle depending on a desired steering angle, wherein it is determined whether the rotation angle lies in a first angular range or a second angular range different from the first angular range, wherein the desired steering angle is determined in the first angular range of the rotation angle depending on the rotation angle, wherein the desired steering angle is determined in the second angular range of the rotation angle depending on the torque, wherein the first angular range comprises the rotation angle associated with the desired steering angle for straight-ahead travel or substantially straight-ahead travel of the vehicle, wherein the second angular range comprises a rotation angle associated with a desired steering angle for a maximum turning angle of the steered wheels.

[0005] Preferably, it is determined that the angle of rotation lies in the first angle range if the angle of rotation or an amount of the angle of rotation is less than a threshold value, in particular of 50°, or it is determined that the angle of rotation lies in the first angle range if the angle of rotation or an amount of the angle of rotation is less than or equal to a threshold value, in particular of 50°.

[0006] Preferably, it is determined that the angle of rotation lies in the second angle range if the angle of rotation or an amount of the angle of rotation is greater than or equal to a threshold value, in particular of 50°, or it is determined that the angle of rotation lies in the second angle range if the angle of rotation or an amount of the angle of rotation is greater than a threshold value, in particular of 50°.

[0007] Preferably, the operating element detects a rotation angle between -60° and 60°, wherein the first angular range comprises rotation angles between -50° and 50°, wherein the second angular range comprises rotation angles between -60° and -50°, in particular including -50°, or between 50° and 60°, in particular including 50°.

[0008] It is preferably provided that at the boundary between the first angular range and the second angular range, a first target steering angle is determined as a function of the angle of rotation, a second target steering angle is determined as a function of the torque, and the target steering angle is determined as a function of the first target steering angle and as a function of the second target steering angle, in particular that the first target steering angle and the second target steering angle are mapped to the target steering angle with a linear function.

[0009] It is preferably provided that the target steering angle is determined in the first angle range as a function of a first gear ratio and in the second angle range as a function of a second gear ratio, wherein the second gear ratio is more direct than the first gear ratio.

[0010] It is preferably provided that the target steering angle is determined in the first angle range as a function of a first gear ratio and in the second angle range as a function of a second gear ratio, wherein the second gear ratio is more direct than the first gear ratio.

[0011] The steering system for a vehicle provides that the steering system comprises an operating element for detecting a rotation angle, wherein a torque provided by the operating element is detected or provided, wherein the steering system comprises a steering actuator for moving steered wheels of the vehicle depending on a target steering angle, wherein the steering system is designed to determine whether the rotation angle lies in a first angular range or a second angular range different from the first angular range, wherein the steering system is designed to determine the target steering angle in the first angular range of the rotation angle depending on the rotation angle, wherein the steering system is designed to determine the target steering angle in the second angular range of the rotation angle depending on the torque, wherein the first angular range comprises the rotation angle that is assigned to the target steering angle for straight-ahead travel or substantially straight-ahead travel of the vehicle,wherein the second angular range comprises a rotation angle associated with a desired steering angle for a maximum turning angle of the steered wheels.

[0012] For example, the steering system is designed to determine that the angle of rotation lies in the first angle range if the angle of rotation or an amount of the angle of rotation is less than a threshold value, in particular of 50°, or to determine that the angle of rotation lies in the first angle range if the angle of rotation or an amount of the angle of rotation is less than or equal to a threshold value, in particular of 50°.

[0013] For example, the steering system is designed to determine that the angle of rotation lies in the second angle range if the angle of rotation or an amount of the angle of rotation is greater than or equal to a threshold value, in particular of 50°, or to determine that the angle of rotation lies in the second angle range if the angle of rotation or an amount of the angle of rotation is greater than a threshold value, in particular of 50°.

[0014] For example, the steering system is designed to detect a rotation angle between -60° and 60° with the operating element, wherein the first angular range comprises rotation angles between -50° and 50°, wherein the second angular range comprises rotation angles between -60° and -50°, in particular including -50°, or between 50° and 60°, in particular including 50°.

[0015] For example, the steering system is designed to determine a first target steering angle at the boundary between the first angular range and the second angular range as a function of the angle of rotation, to determine a second target steering angle as a function of the torque, and to determine the target steering angle as a function of the first target steering angle and as a function of the second target steering angle, in particular to map the first target steering angle and the second target steering angle to the target steering angle using a linear function.

[0016] For example, the steering system is designed to determine the target steering angle in the first angle range depending on a first gear ratio and in the second angle range depending on a second gear ratio, wherein the second gear ratio is more direct than the first gear ratio.

[0017] A vehicle that includes the steering system has corresponding advantages.

[0018] Further advantageous embodiments can be found in the following description and the drawing. The drawing shows: Fig. 1 a schematic representation of a vehicle, Fig. 2 a flowchart with steps of a method for operating a steering system of the vehicle.

[0019] In Fig. 1 schematically shows a vehicle 100 with a steering system 102. The steering system 102 is, for example, a steer-by-wire steering system.

[0020] The steering system 102 includes an operating element 104, e.g., a joystick, for detecting a rotation angle. Furthermore, a torque provided by the operating element 104 is detected or provided by the operating element 104.

[0021] The operating element 104 is designed, for example, to detect a rotation angle between -60° and 60°.

[0022] The steering system 102 includes a steering actuator 106 for moving steered wheels 108 of the vehicle 100 depending on a desired steering angle.

[0023] The steering system 102 is designed to determine whether the angle of rotation lies in a first angular range or a second angular range different from the first angular range.

[0024] The first angle range includes the angle of rotation that is assigned to the target steering angle, e.g. 0°, for straight-ahead travel of the vehicle 100.

[0025] The second angle range comprises a rotation angle that is assigned to a desired steering angle, e.g. -540° or +540°, for a maximum turning angle of the steered wheels 108.

[0026] The first angle range, for example, includes angles of rotation between -50° and 50°. The second angle range, for example, includes angles of rotation between -60° and -50°.

[0027] The first angle range, for example, includes angles of rotation exclusively -50°. The second angle range, for example, includes angles of rotation including -50°.

[0028] Other divisions of the angular ranges, e.g. with a limit between 45° and 55°, in particular 49° or 51°, can also be provided.

[0029] The steering system 102 is designed to determine the desired steering angle in the first angular range of the angle of rotation depending on the angle of rotation.

[0030] The steering system 102 is designed to determine the desired steering angle in the second angular range of the rotation angle depending on the torque.

[0031] The steering system 102 is designed, for example, to determine that the angle of rotation lies in the first angle range when an amount of the angle of rotation δ be is smaller than a threshold value Threshold_1, in particular of 50°. |δbe| <Schwelle_1

[0032] The steering system 102 is designed, for example, to determine that the angle of rotation lies in the second angle range if the amount of the angle of rotation is greater than or equal to the threshold value Threshold_1, in particular the threshold value of 50°. |δbe|≥threshold_1

[0033] Instead, it may be provided to determine that the angle of rotation lies in the first angle range if the amount of the angle of rotation is less than or equal to the threshold value.

[0034] Instead, it may be provided to determine that the angle of rotation lies in the second angle range if the amount of the angle of rotation is greater than the threshold value.

[0035] Two corresponding threshold values ​​can be provided, one for negative rotation angles and one for positive rotation angles.

[0036] For example, the steering system 102 is configured to determine the target steering angle in the first angular range based on a first gear ratio and in the second angular range based on a second gear ratio. In this example, the second gear ratio is more direct than the first gear ratio.

[0037] For example, the steering system 102 is designed to determine the desired steering angle δ Rad in the first angular range depending on the angle of rotation δ be and a vehicle longitudinal speed v x to determine: δRad=f(vxδbe)⋅δbe where f(v x δ be ) is the first translation.

[0038] For example, the steering system 102 is designed to determine the desired steering angle δ Rad in the second angular range depending on the angle of rotation δ be , from the torque M be and the vehicle longitudinal speed v x to determine: δRad=f(vxδbe,Mbe)⋅Mbe where f(v x δ be , Mbe ) represents the second translation.

[0039] In one example, the steering system 102 is configured to determine a first target steering angle at the boundary between the first angular range and the second angular range as a function of the angle of rotation, to determine a second target steering angle as a function of the torque, and to determine the target steering angle as a function of the first target steering angle and as a function of the second target steering angle.

[0040] For example, the steering system 102 is configured to map the first target steering angle and the second target steering angle to the target steering angle using a linear function.

[0041] In Fig. Figure 2 schematically illustrates a method for operating the steering system 102 of the vehicle 100. The steering system 102 includes, for example, a computing device configured to execute the method.

[0042] The method includes a step 202.

[0043] In step 202, the angle of rotation and the torque are recorded using the control element 104.

[0044] The angle of rotation is measured between -60° and 60°, for example.

[0045] A step 204 is then executed.

[0046] In step 204 it is determined whether the angle of rotation lies in the first angle range or in the second angle range.

[0047] In this example, the first angle range includes angles of rotation between -50° and 50°. The second angle range includes angles of rotation between -60° and -50°, including -50°, and angles of rotation between 50° and 60°, including 50°.

[0048] For example, it is determined that the angle of rotation is in the first angle range if the amount of the angle of rotation is smaller than the threshold value.

[0049] For example, it is determined that the angle of rotation lies in the second angle range if the magnitude of the angle of rotation is greater than or equal to the threshold value.

[0050] The threshold value is, for example, 50°. Instead, a different division into the value ranges described for the steering system 102, or a different threshold value, or a different type of comparison with the threshold value may be provided.

[0051] If the angle of rotation is within the first value range, step 206 is executed. If the angle of rotation is within the second value range, step 208 is executed.

[0052] It may be provided to carry out step 206 and step 208 in an area around the boundary between the value ranges.

[0053] In step 206, the target steering angle in the first angle range of the rotation angle is determined depending on the rotation angle.

[0054] In step 208, the target steering angle in the second angle range of the rotation angle is determined depending on the torque.

[0055] The target steering angle is determined in the first angle range depending on the first gear ratio and in the second angle range depending on the second gear ratio.

[0056] This applies an indirect steering ratio to the first angular range, e.g., up to + / -50°. The indirect steering ratio is modeled on the ratio of a steering wheel, for example. The first angular range corresponds to a first target steering angle range.

[0057] In the remaining second angular range, e.g., up to + / -60°, i.e., within a range of 10° of the angle of rotation, an increasing steering torque is generated up to a limit stop torque, and a remaining second target steering angle range is realized as a function of the torque. In an optional step 210, in the region of the boundary between the first angular range and the second angular range, a first target steering angle is determined as a function of the angle of rotation, and a second target steering angle is determined as a function of the torque.

[0058] In step 210, the target steering angle is determined based on the first target steering angle and the second target steering angle. For example, the first target steering angle and the second target steering angle are mapped to the target steering angle using the linear function. This creates a smooth transition between the two ranges.

[0059] A step 212 is then executed.

[0060] In step 212, the steered wheels 108 are steered with the steering actuator 106 depending on the desired steering angle.

[0061] Step 202 is then executed.

Claims

[1] Method for operating a steering system (102) of a vehicle (100), characterized bythat the steering system (102) comprises an operating element (104) for detecting a rotation angle, wherein a torque provided by the operating element (104) is detected or provided, wherein the steering system (102) comprises a steering actuator (106) for moving steered wheels (108) of the vehicle (100) depending on a desired steering angle, wherein it is determined (204) whether the rotation angle lies in a first angular range or a second angular range different from the first angular range, wherein the desired steering angle in the first angular range of the rotation angle is determined depending on the rotation angle (206), wherein the desired steering angle in the second angular range of the rotation angle is determined depending on the torque (208), wherein the first angular range comprises the rotation angle that is assigned to the desired steering angle for straight-ahead travel or substantially straight-ahead travel of the vehicle (100), wherein the second angular range comprises a rotation angle,which is assigned to a desired steering angle for a maximum turning angle of the steered wheels (108). [2] Method according to claim 1, characterized by that it is determined (204) that the angle of rotation lies in the first angle range if the angle of rotation or an amount of the angle of rotation is less than a threshold value, in particular of 50°, or that it is determined (204) that the angle of rotation lies in the first angle range if the angle of rotation or an amount of the angle of rotation is less than or equal to a threshold value, in particular of 50°. [3] Method according to claim 1 or 2, characterized bythat it is determined (204) that the angle of rotation lies in the second angle range if the angle of rotation or an amount of the angle of rotation is greater than or equal to a threshold value, in particular of 50°, or that it is determined (204) that the angle of rotation lies in the second angle range if the angle of rotation or an amount of the angle of rotation is greater than a threshold value, in particular of 50°. [4] Method according to one of the preceding claims, characterized by that a rotation angle between -60° and 60° is detected with the operating element (202), wherein the first angular range comprises rotation angles between -50° and 50°, wherein the second angular range comprises rotation angles between -60° and -50°, in particular including -50°, or between 50° and 60°, in particular including 50°. [5] Method according to one of the preceding claims, characterized bythat at the boundary between the first angular range and the second angular range, a first target steering angle is determined as a function of the angle of rotation (210), a second target steering angle is determined as a function of the torque, and the target steering angle is determined as a function of the first target steering angle and as a function of the second target steering angle, in particular that the first target steering angle and the second target steering angle are mapped to the target steering angle with a linear function. [6] Method according to one of the preceding claims, characterized by that the target steering angle is determined in the first angle range as a function of a first gear ratio (206) and in the second angle range as a function of a second gear ratio (208), the second gear ratio being more direct than the first gear ratio. [7] Method according to one of the preceding claims, characterized bythat the target steering angle is determined in the first angle range as a function of a first gear ratio (206) and in the second angle range as a function of a second gear ratio (208), the second gear ratio being more direct than the first gear ratio. [8] Steering system (102) for a vehicle (100), characterized bythat the steering system (102) comprises an operating element (104) for detecting a rotation angle, wherein a torque provided by the operating element (104) is detected or provided, wherein the steering system (102) comprises a steering actuator (106) for moving steered wheels (108) of the vehicle (100) depending on a target steering angle, wherein the steering system (102) is designed to determine whether the rotation angle lies in a first angular range or a second angular range different from the first angular range, wherein the steering system (102) is designed to determine the target steering angle in the first angular range of the rotation angle depending on the rotation angle, wherein the steering system is designed to determine the target steering angle in the second angular range of the rotation angle depending on the torque, wherein the first angular range comprises the rotation angle that is assigned to the target steering angle for straight-ahead travel or substantially straight-ahead travel of the vehicle,wherein the second angular range comprises a rotation angle which is associated with a desired steering angle for a maximum turning angle of the steered wheels (108). [9] Steering system (102) according to claim 8, characterized by in that the steering system (102) is designed to determine that the angle of rotation lies in the first angular range if the angle of rotation or an amount of the angle of rotation is less than a threshold value, in particular of 50°, or to determine that the angle of rotation lies in the first angular range if the angle of rotation or an amount of the angle of rotation is less than or equal to a threshold value, in particular of 50°. [10] Steering system (102) according to claim 8 or 9, characterized byin that the steering system (102) is designed to determine that the angle of rotation lies in the second angular range if the angle of rotation or an amount of the angle of rotation is greater than or equal to a threshold value, in particular of 50°, or to determine that the angle of rotation lies in the second angular range if the angle of rotation or an amount of the angle of rotation is greater than a threshold value, in particular of 50°. [11] Steering system (102) according to one of claims 8 to 10, characterized by in that the steering system (102) is designed to detect a rotation angle between -60° and 60° with the operating element, wherein the first angular range comprises rotation angles between -50° and 50°, wherein the second angular range comprises rotation angles between -60° and -50°, in particular including -50°, or between 50° and 60°, in particular including 50°. [12] Steering system (102) according to one of claims 8 to 11, characterized bythat the steering system (102) is designed to determine a first target steering angle at the boundary between the first angular range and the second angular range as a function of the angle of rotation, to determine a second target steering angle as a function of the torque, and to determine the target steering angle as a function of the first target steering angle and as a function of the second target steering angle, in particular to map the first target steering angle and the second target steering angle to the target steering angle using a linear function. [13] Steering system (102) according to one of claims 8 to 12, characterized by that the steering system (102) is designed to determine the desired steering angle in the first angular range as a function of a first gear ratio and in the second angular range as a function of a second gear ratio, wherein the second gear ratio is more direct than the first gear ratio. [14] Vehicle (100), characterized by that the vehicle comprises the steering system (102) according to one of claims 8 to 13.

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