Steer-by-wire system and method for operating a steer-by-wire system

Abstract

The invention relates to a steer-by-wire system (1), comprising a steering handle (2), a steering column module (3) and a steering transmission (4), wherein the steering column module (3) and the steering transmission (4) are connected in a data technology connection, wherein a rotation angle sensor (6) and an actuator (7) for generating a counter torque on the steering handle (2) are arranged in the steering column module (3), wherein a steering angle adjuster (9) is arranged in the steering column module (3), wherein the steering angle adjuster (9) is connected in a data technology connection to at least one driver assistance system (17), the steering angle adjuster (9) being designed to receive a target angle from the at least one driver assistance system (17) and to generate a torque for setting the target angle by means of the actuator (7) or a further actuator. The invention also relates to a method for operating a steer-by-wire system (1).

Description

Technical Field

[0001] The present invention relates to a steer-by-wire system and a method for operating the steer-by-wire system. Background Technology

[0002] A steer-by-wire system typically includes a steering handle, a steering column module, and a steering transmission mechanism. The steering column module and steering transmission mechanism are digitally connected but mechanically uncoupled. The steering column module houses a rotation angle sensor and an actuator for generating counter-torque on the steering handle. This actuator is, for example, a servo motor. It can be specified that the actuator receives its control signal from the steering transmission mechanism or even directly from the steering column module, generating counter-torque based, for example, on the rotation angle and vehicle speed. Such a steer-by-wire system is known from document US 10,906,581B2.

[0003] In modern motor vehicles where the driver assistance system fully or almost fully undertakes the steering task, the driver assistance system pre-defines the trajectory to be executed by the steering angle adjuster. The steering angle adjuster then receives the target steering angle as an input variable and makes the actual steering angle as close as possible to the target steering angle. Such a steering angle adjuster is known, for example, from the literature DE 10 2017 214 380 A1.

[0004] Conversely, in assisted driving, the driver primarily retains sovereignty over the driving task, where the driver assistance system generates additional steering torque implemented by the steering drivetrain. This coordination is not easy here due to mechanical decoupling, as the position adjuster in the steering drivetrain must prioritize between the driver's pre-defined actions and the driver assistance system. Summary of the Invention

[0005] The technical problem to be solved by this invention is to implement a steer-by-wire system that can better implement steering torque recommendations for assisted driving. Another technical problem to be solved by this invention is to provide a suitable method for operating the steer-by-wire system.

[0006] The solution to the above-mentioned technical problem is obtained through a steer-by-wire system and a method for operating the steer-by-wire system.

[0007] Therefore, the steer-by-wire system includes a steering handle, a steering column module, and a steering transmission mechanism, wherein the steering column module and the steering transmission mechanism are digitally connected. The steering column module houses at least one rotation angle sensor, an actuator for generating counter-torque on the steering handle, and a steering angle adjuster, wherein the steering angle adjuster is digitally connected to at least one driver assistance system. The steering angle adjuster is designed to receive a target angle from the at least one driver assistance system and generate torque for setting the target angle via the actuator or another actuator. This greatly simplifies coordination, as the steering transmission mechanism receives only one signal from the steering column module: the signal from the rotation angle sensor. The driver feels the additional torque on the steering handle and can then determine whether to follow the recommendation or compensate for it with greater manual torque or ignore it.

[0008] In one implementation, the steering angle adjuster is designed such that it generates a numerically limited torque via an actuator, which can be over-controlled (German: überlenkt) or over-steering by the driver. This ensures that the driver can ignore the steering torque recommendations of the driver assistance system at any time by using their reverse steering. The torque is, for example, limited to 1 Nm to 2 Nm.

[0009] In another implementation, the steering angle adjuster is connected to at least one driver assistance system via a bus system. This simplifies data transmission, particularly in implementations where multiple driver assistance systems can generate steering torque recommendations.

[0010] In another embodiment, a control device is arranged in the steering column module, the control device being designed to control the actuator. Here, the control device can obtain control signals from the control device of the steering transmission mechanism or directly from the rotation angle sensor in the steering column module, wherein the counter torque is additionally generated based on the vehicle speed.

[0011] In another implementation, the steer-by-wire system is designed such that numerical limits can be altered via user input and / or at least one driver assistance system. This allows the user to personalize the steering feel within predefined limits, and / or allows driver assistance systems to give more emphasis to individual steering torque recommendations based on priority, due to increased perceptibility at the steering lever.

[0012] The methodological design scheme completely references the above design scheme. Attached Figure Description

[0013] The present invention will be further described below with reference to preferred embodiments.

[0014] Figure 1 shows a schematic block diagram of a steer-by-wire system. Detailed Implementation

[0015] The steer-by-wire system 1 shown in Figure 1 includes a steering handle 2, a steering column module 3, and a steering transmission mechanism 4. The steering handle 2 is mechanically connected to the steering column 5. At least one rotation angle sensor 6, an actuator 7, a control device 8, and a steering angle adjuster 9 are also arranged in the steering column module 3. The steering transmission mechanism 4 includes a control device 10 and two half-motors 11 and 12 (German: Halbmotor), each half-motor having its own power electronics 13 and 14. The two half-motors 11 and 12 operate on a common rotor 15, which is coupled to a rack 16 via a transmission mechanism (not shown). The half-motors 11 and 12, and their corresponding power electronics 13 and 14, are powered by independent power supplies U1 and U2, respectively.

[0016] The steer-by-wire system 1 operates as follows: If the driver turns the steering handle 2, the set steering wheel angle... The rotation angle sensor 6 measures and transmits the force to the control device 10. The control device 10 then determines the rack force to be applied to the rack 16 via a transmission mechanism (not shown) and transmits control signals to the two power electronics devices 13, 14. The control device 10 also considers at least the vehicle speed V. Because it is divided into two power electronics devices 13, 14 and two half-motors 11, 12, the steering transmission mechanism 4 is fail-safe.

[0017] Control device 10 transmits signals in parallel to control device 8, causing control device 8 to control actuator 7, which then generates a tactile counter-torque on steering column 5, which can be felt on steering handle 2. Actuator 7 is designed, for example, as an electric motor and is also referred to as a force feedback actuator.

[0018] If the driver assistance system 17 now wants to generate steering torque suggestions for the driver of the motor vehicle, it will target the angle The information is transmitted to the steering angle adjuster 9, whereby the driver assistance system 17 has received, for example, the current actual angle transmitted from the control device 10. The steering angle adjuster 9 is connected to the actuator 7 and generates additional torque to set the target angle. From a practical perspective The torque is redirected to the steering angle adjuster 9. Here, the torque value is limited so that it can be over-controlled by the driver at any time, but the driver feels the torque. If the driver wants to follow the steering torque recommendation, he only needs manual torque that does not produce a reaction. Therefore, the rotation angle... (Or the actual angle) changes. This changed rotation angle is transmitted to the control device 10 and implemented by the steering transmission mechanism 4. Conversely, if the driver of the motor vehicle over-controls the torque through the corresponding manual torque, the steering will only be performed according to the driver's preset steering.

[0019] Here, the driver can set the torque value via a control unit (not shown). This means determining the level of steering feedback the user wants. A limit can be preset, within which the user can determine the maximum torque value. Alternatively, the driver assistance system 17 can also change the maximum value. For this purpose, the steering angle adjuster 9 is set to provide greater torque.

[0020] List of reference numerals in the attached diagram:

[0021] 1. Steer-by-wire system

[0022] 2. Steering handle

[0023] 3. Steering column module

[0024] 4. Steering transmission mechanism

[0025] 5. Steering column

[0026] 6. Rotation Angle Sensor

[0027] 7 Actuator

[0028] 8. Control equipment

[0029] 9. Steering angle adjuster

[0030] 10. Control equipment

[0031] 11 and 12 half motors

[0032] 13, 14 Power electronic devices

[0033] 15 Rotors

[0034] 16 racks

[0035] 17 Driver Assistance Systems

[0036] Rotation angle

[0037] Target Angle

[0038] V speed

Claims

1. A steer-by-wire system (1), comprising a steering handle (2), a steering column module (3), and a steering transmission mechanism (4), wherein, The steering column module (3) and the steering transmission mechanism (4) are connected digitally but not mechanically coupled. A rotation angle sensor (6) and an actuator (7) for generating counter-torque on the steering handle (2) are arranged in the steering column module (3). Its features are, A steering angle adjuster (9) is arranged in the steering column module (3), wherein the steering angle adjuster (9) is connected to at least one driver assistance system (17) in a data technology manner, and wherein the steering angle adjuster (9) is designed to receive a target angle (φ) from the at least one driver assistance system (17). soll ) and through the actuator (7) or another actuator, a force is generated for setting the target angle (φ). soll The torque of the steering transmission mechanism (4) is obtained only from the signal of the steering column module (3), i.e. the signal of the rotation angle sensor (6).

2. The steer-by-wire system according to claim 1, characterized in that, The steering angle adjuster (9) is designed such that it generates a numerically limited torque via the actuator (7) controlled by the driver of the motor vehicle.

3. The steer-by-wire system according to claim 1 or 2, characterized in that, The steering angle adjuster (9) is connected to the at least one driver assistance system (17) via a bus system.

4. The steer-by-wire system according to any one of the preceding claims, characterized in that, A control device (8) is arranged in the steering column module (3), the control device being designed to control the actuator (7).

5. The steer-by-wire system according to claim 2, characterized in that, The steer-by-wire system (1) is designed such that the numerical limitations can be changed by user input and / or by at least one driver assistance system (17).

6. A method for operating a steer-by-wire system (1) via a steering handle (2), a steering column module (3), and a steering transmission mechanism (4), wherein, The steering column module (3) and the steering transmission mechanism (4) are connected digitally but not mechanically coupled. The steering column module (3) contains a rotation angle sensor (6), an actuator (7) for generating counter-torque on the steering handle (2), and a steering angle adjuster (9). The steering angle adjuster (9) receives a target angle (φ) from at least one driver assistance system (17). soll ) and through the actuator (7) or another actuator, a force is generated for setting the target angle (φ). soll The torque of the steering transmission mechanism (4) is obtained only from the signal of the steering column module (3), i.e. the signal of the rotation angle sensor (6).

7. The method according to claim 6, characterized in that, The steering angle adjuster (9) generates a torque that is numerically limited and controlled by the override of the motor vehicle driver via the actuator (7).

8. The method according to claim 6 or 7, characterized in that, The driver assistance system (17) transmits data to the steering angle adjuster (9) via a bus system.

9. The method according to any one of claims 6 to 8, characterized in that, The actuator (7) is controlled by the control device (8) in the steering column module (3).

10. The method according to claim 7, characterized in that, The numerical limitations can be changed by user input and / or by at least one driver assistance system (17).

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