Apparatus and method for generating a steering sense in a steering system, vehicle including the apparatus
By using a computing device and a torque sensor in the steering system to calculate friction torque, the problem of lack of effective friction sensing in the existing technology is solved, and a more comfortable and precise steering feeling is achieved.
Patent Information
- Application Number
- CN202380045617.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-06-08
- Filing Date
- 2023-06-06
- Publication Date
- 2025-01-21
AI Technical Summary
The existing steering system lacks effective friction perception when achieving a comfortable and precise steering feel, affecting the driving experience.
By introducing a calculation device and a torque sensor into the steering system, the friction torque is calculated and generated based on the torque difference between the motor torque and the operating element (such as a torsion bar), thereby producing a steering feel.
It achieves efficient generation of steering feeling in the steering system, provides a more comfortable and precise driving experience, and has greater freedom to adapt to different driving conditions.
Smart Images
Figure CN119343290A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a device and a method for generating a steering feel in a steering system and a vehicle comprising the device. Background Art
[0002] A certain degree of friction is required to achieve a comfortable and precise steering feel. A steering system can include a steering wheel or other operating elements for steering. The area in which the movement of the operating element does not yet exist, that is to say the area in which the driver begins to move the operating element, is particularly important. Summary of the invention
[0003] The method and device according to the independent claim improves the comfortable steering feel by generating a friction feel. The steering feel is generally achieved, for example, by generating a friction feel, a restoring force feel and damping.
[0004] A method for generating a steering feel in a steering system comprising a motor and an operating element, in particular a torsion bar, connected to one another via a transmission provides for determining a motor torque of a motor and a torque at an operating element, in particular a torsion bar torque at a torsion bar, wherein the converted motor torque is determined as a function of the motor torque and a transmission ratio and an efficiency of the transmission, wherein the friction torque is determined as a function of the difference between the converted motor torque and the torque at the operating element, in particular a torsion bar torque, or wherein the converted torque is determined as a function of the torque at the operating element and a transmission ratio and an efficiency of the transmission, wherein the friction torque is determined as a function of the difference between the motor torque and the converted torque at the operating element, and wherein a setpoint friction torque is determined as a function of the friction torque, wherein the setpoint motor torque is determined as a function of the nominal friction torque, and wherein the motor is actuated to generate the setpoint motor torque. Using these two torques and adding the efficiency of the motor and the transmission, the system friction, i.e. the friction between the motor torque and the torque at the operating element, can be calculated at each point in time. First, the actual system friction is determined, for example, by corresponding addition of the motor torque and the torque at the operating element, wherein the motor torque is first converted to the same level as the torque at the operating element and the efficiency of the motor and transmission is taken into account. This means, for example, that motor torque*=motor torque×transmission ratio×efficiency, friction torque=motor torque*-torsion bar torque. Similarly, the reference point for the difference formation can also be at the level of the motor torque, that is, the torsion bar torque is converted using the transmission ratio. The motor torque is then corrected using the efficiency.
[0005] The setpoint friction torque is preferably determined in dependence on a predetermined coefficient, with which the friction torque is varied. By continuously calculating the friction with the friction coefficient, the active friction can also correspond to a multiple of the mechanical friction. This results in a large degree of freedom for generating the steering feel.
[0006] The sign for the coefficient is preferably determined as a function of the asymmetry with respect to the reference value for the friction torque. Based on the sign, the friction acts in the desired direction of movement. This serves to compensate for asymmetric effects.
[0007] The setpoint friction torque is preferably limited in value to a maximum value.
[0008] The maximum value is preferably determined as a function of the vehicle speed.
[0009] Preferably, provision is made for a switch to a maximum value to take place when a certain steering speed is exceeded.
[0010] The setpoint friction torque is preferably filtered.
[0011] The setpoint friction torque is preferably filtered using a low-pass filter.
[0012] A device for generating a steering feel in a steering system, the steering system comprising a motor and an operating element, in particular a torsion bar, which are connected to each other via a transmission, the device comprising a computing device, which is designed to implement the method as a function of a detected motor torque and a detected torque at the operating element, in particular a torsion bar torque.
[0013] The device preferably comprises a torque sensor, in particular a torsion bar torque sensor, which is designed to detect a torque, in particular a torsion bar torque.
[0014] A vehicle has corresponding advantages, and includes a steering system having the device. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Further advantageous embodiments can be seen from the following description and the accompanying drawings. In the accompanying drawings:
[0016] Figure 1 shows a schematic diagram of a vehicle having a steering system,
[0017] Figure 2 shows a portion of the frame of an adjuster for a steering system,
[0018] Figure 3 A flow chart with steps in a method for generating a steering feel is shown. DETAILED DESCRIPTION
[0019] exist Figure 1A vehicle 100 is schematically shown in FIG. The vehicle 100 includes a steering system 102 and a computing device 104 .
[0020] The steering system 102 includes a motor 106 and a torsion bar 108 which are connected to each other via a transmission 110 .
[0021] The vehicle 100 includes a device 112 for generating a steering feel in the steering system 102. The device 112 includes a computing device 104, a motor 106, a transmission mechanism 110, and a torsion bar torque sensor 114, which is configured to detect a torsion bar torque. The torsion bar torque sensor 114 is configured to transmit the torsion bar torque to the computing device 104 via a signal line 116.
[0022] The computing device 104 is designed to control the steering system 102 . The computing device 104 is designed to control the motor 106 via a control line 118 in order to generate a motor torque which is determined by the computing device 104 .
[0023] exist Figure 2 2 shows a part of the architecture of a controller 200, with which the computing device 104 controls the steering system 102. The torques mentioned below are torques in the example in Nm.
[0024] The architecture 200 provides a function 202 for determining a maximum torque 202 - 1 as a function of a vehicle speed 202 - 2 and for determining a scaling factor 202 - 3 as a function of a torsion bar torque 202 - 4 .
[0025] The framework 200 provides a function 204 for determining a speed-dependent modified maximum torque 204-1 dependent on a maximum torque 202-1, a scaling factor 202-3 and dependent on a steering speed 204-2. The steering speed 204-2 is the speed in rad / s at which the steering system 102 or the driver steers.
[0026] The architecture 200 provides a function 206 for determining a desired motor torque 206 - 1 as a function of a motor torque 206 - 2 , the speed-dependent corrected maximum torque 204 - 1 , and a torsion bar torque 202 - 4 .
[0027] In the example, the setpoint motor torque 206-1 is determined as a function of parameter 206-3, which indicates by its sign whether the motor 106 generates a motor torque that supports the driver or acts against the driver. For example, when turning left, if the motor torque 206-2 acts against the driver, a negative sign is set, and if the motor torque 206-2 supports the driver, a positive sign is set. For example, when turning right, if the motor torque 206-2 acts against the driver, a positive sign is set, and if the motor torque 206-2 supports the driver, a negative sign is set.
[0028] In the example, the setpoint motor torque 206 - 1 is determined as a function of a parameter 206 - 4 , which represents the transmission ratio and the efficiency of the transmission 110 .
[0029] In the example, a subfunction 206 - 5 is provided, with which the converted motor torque 206 - 6 is determined as a function of the product of the motor torque 206 - 2 and the parameters 206 - 3 , 206 - 4 .
[0030] In the example, a subfunction 206 - 7 is provided, with which the friction torque 206 - 8 is determined as a function of the difference between the torsion bar torque 202 - 4 and the converted motor torque 206 - 6 .
[0031] In the example, a subfunction 206 - 9 is provided, with which an unlimited setpoint friction torque 206 - 10 is determined as a function of the friction torque 206 - 8 .
[0032] In one specific embodiment, it is provided that the unlimited setpoint friction torque 206 - 10 is determined as a function of the product of the friction torque 206 - 8 and a predefined coefficient 206 - 11 , with which the friction torque is varied.
[0033] In one embodiment, it is provided that the unlimited setpoint friction torque 206-10 is determined depending on the sign of the coefficient, which sign depends on the asymmetry with respect to the reference value 206-12 for the friction torque 206-8. If the friction torque 206-8 is greater than the reference value 206-12, the sign is positive, for example. If the friction torque 206-8 is less than the reference value 206-12, the sign is negative, for example. The reference value 206-12 is zero, for example.
[0034] If, instead of the friction torque 206 - 8 of 0.25 Nm, an unlimited setpoint friction torque of 1 Nm is to be provided, the factor would be 4, for example.
[0035] In the example, a subfunction 206 - 13 is provided, with which a target friction torque 216 - 14 is determined as a function of the unlimited target friction torque 206 - 10 and the speed-dependent corrected maximum torque 204 - 1 .
[0036] In the example, it is provided that the unlimited setpoint friction torque 206-10 is limited in value to the speed-dependent corrected maximum torque 204-1, and that the setpoint friction torque 216-14 is assigned the same sign as the unlimited setpoint friction torque 206-10. It can be provided that when a certain steering speed is exceeded, a switch is made to a maximum value, and that the unlimited setpoint friction torque 206-10 is limited in value to the maximum value.
[0037] In one example, the target friction torque is determined using a subfunction of a plurality of subfunctions that predetermine the corresponding target torque. In one example, the sum of these target torques is converted into the target motor torque by the controller.
[0038] In the example, a subfunction 206-15 is provided, with which a desired motor torque 206-1 is determined as a function of a desired friction torque 216-14 and as a function of desired torques of other subfunctions. It can be provided that the subfunction 206-15 is used to determine whether the desired motor torque 206-1 is determined as a function of the desired friction torque 216-14 or as a function of a further torque 216-17. For example, the further torque 216-17 is determined independently of the desired friction torque 216-14 as a function of the speed-dependent corrected maximum torque 204-1, wherein the speed-dependent corrected maximum torque 204-1 is scaled in particular as a function of the steering speed 204-2.
[0039] The computing device 104 is configured to implement the following Figure 3 A method for generating a steering feel in a steering system 102 is described.
[0040] The method includes step 300 .
[0041] In step 300 , the motor torque 204 - 2 of the motor 106 and the torsion bar torque 202 - 4 at the torsion bar 108 are determined.
[0042] Step 302 is then performed.
[0043] In step 302 , the converted motor torque 206 - 6 is determined as a function of the motor torque 206 - 2 and the transmission ratio and efficiency of the transmission 110 .
[0044] Step 304 is then performed.
[0045] In step 304 , the friction torque 206 - 8 is determined as a function of the difference between the converted motor torque 206 - 6 and the torsion bar torque 202 - 4 .
[0046] It may be provided that the setpoint friction torque 206 - 14 is determined as a function of a predefined factor 206 - 11 , with which the friction torque 206 - 8 is varied.
[0047] It can be provided that the sign for the coefficient 206 - 11 is determined as a function of the asymmetry with respect to the reference value 206 - 12 for the friction torque 206 - 8 .
[0048] Step 306 is then performed.
[0049] In step 306 , the setpoint friction torque 206 - 14 is determined as a function of the friction torque 206 - 8 .
[0050] It may be provided that the setpoint friction torque 206 - 14 is limited in value to a maximum value 204 - 1 .
[0051] It may be provided that maximum value 204 - 1 is determined as a function of vehicle speed 202 - 2 . It may be provided that maximum value 204 - 1 is determined as a function of other or additional variables, such as, for example, a torsion bar torque or a transverse acceleration.
[0052] Optionally, step 308 is performed.
[0053] In step 308, the setpoint friction torque 206-14 is filtered. It may be provided that the setpoint friction torque 206-14 is filtered using a low-pass filter.
[0054] Step 310 is then performed.
[0055] In step 310 , the setpoint motor torque 206 - 1 is determined as a function of the setpoint friction torque 206 - 14 and the motor torque 206 - 2 .
[0056] Step 312 is then performed.
[0057] In step 312 , motor 106 is activated in order to generate setpoint motor torque 206 - 1 .
[0058] In the example, step 300 is then carried out.
[0059] In the example described, the reference point for the difference in torque is at the level of the torque at the operating element. It can also be provided that the reference point is at the level of the motor torque. In this case, the converted torque is determined as a function of the torque at the operating element and the transmission ratio and efficiency of the transmission mechanism, and the friction torque is determined as a function of the difference between the motor torque and the converted torque at the operating element.
Claims
1. A method for generating a steering feel in a steering system (102), the steering system comprising a motor (106) and an operating element connected to one another via a transmission (110), wherein: A motor torque of the motor (106) and a torque at an operating element, in particular a torsion bar torque (202-4) at a torsion bar (108) are determined (300), wherein: - determining (302) the converted motor torque (206-6) as a function of the motor torque (206-2) and the transmission ratio and efficiency of the transmission mechanism (110), wherein the friction torque (206-8) is determined (304) as a function of the difference between the converted motor torque (206-6) and the torque (202-4), or - the converted torque is determined as a function of the torque at the operating element and the transmission ratio and efficiency of the transmission, wherein the friction torque is determined as a function of the difference between the motor torque and the converted torque at the operating element, And wherein, a rated friction torque (206-14) is determined (308) depending on the friction torque (206-8), wherein a rated motor torque (206-1) is determined (310) depending on the rated friction torque (206-14), and wherein the motor (106) is controlled to generate (312) the rated motor torque (206-1).
2. The method according to claim 1, characterized in that The setpoint friction torque (206-14) is determined as a function of a predetermined factor (206-11), by means of which the friction torque (206-8) is varied (304).
3. The method according to claim 2, characterized in that The sign for the coefficient (206-11) is determined (304) in dependence on an asymmetry with respect to a reference value (206-12) for the friction torque (206-8).
4. The method according to any one of the preceding claims, characterized in that The setpoint friction torque (206-14) is limited (306) in terms of value to a maximum value (204-1).
5. The method according to claim 4, characterized in that The maximum value (204-1) is determined (306) in dependence on the vehicle speed (202-2).
6. The method according to claim 4 or 5, characterized in that: When a certain steering speed is exceeded, a switch is made to the maximum value.
7. The method according to any one of the preceding claims, characterized in that The rated friction torque (206-14) is filtered (308).
8. The method according to claim 7, characterized in that The set friction torque (206-14) is filtered (308) using a low-pass filter.
9. A device (112) for generating a steering feel in a steering system (102), the steering system comprising a motor (106) and an operating element connected to each other via a transmission (110), wherein: The device (112) comprises a computing device (106) which is designed to carry out a method according to any one of claims 1 to 8 as a function of a certain motor torque and a detected torque at an operating element, in particular a detected torsion bar torque.
10. The device (112) according to claim 9, characterized in that The device (112) comprises a torque sensor, in particular a torsion bar torque sensor (114), which is designed to detect a torque on the operating element, in particular the torsion bar torque.
11. A vehicle (100), characterized in that The vehicle (100) comprises a steering system (102) having an apparatus (100) according to claim 9 or 10.