Method and controller for controlling a steering system of a vehicle, and steering system of a vehicle

Abstract

A method for controlling a steering system (110) of a vehicle (100) is presented. The method includes determining uniformity (155) of the angular position and velocity of a shaft (122) of a linkage assembly (120) of the steering system (110). The shaft (122) is coupled to another shaft (124) of the linkage assembly (120) by a universal joint (126). The uniformity (155) is determined using at least one sensor signal (135) from at least one sensor (130) of the steering system (110) for detecting rotation of the shaft (122) when a steering torque is input by a driver of the vehicle (100). The angular position and velocity of the shaft (122) are ascertained from the at least one sensor signal (135). The method also includes generating a control signal (157) for controlling at least one actuator (142) of a power steering assembly (140) of the steering system (110). A control signal (157) is generated to include a control parameter defining a correction torque for adjusting the torque provided by at least one actuator (142) to the linkage assembly (120) in response to the uniformity (155).

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a steering system of a vehicle, a controller for controlling a steering system of a vehicle, and a steering system of a vehicle.

[0002] Vehicle steering systems often use universal joints to connect shafts in the steering system's linkages. Universal joints, also known as U-joints or universal couplings, are not constant velocity, meaning that only one of the two shafts connected by them rotates at a constant speed while the other rotates at a variable speed. This is especially true of cardan joints, which can cause an uneven feel when steering the vehicle.

[0003] Against this background, it is an object of the present invention to provide an improved method for controlling a steering system of a vehicle, an improved controller for controlling a steering system of a vehicle, and an improved steering system of a vehicle.

[0004] This object is achieved by a method for controlling a steering system of a vehicle, a controller for controlling a steering system of a vehicle, and a steering system of a vehicle according to the main claims. The invention also relates to a computer program and a computer readable data carrier.

[0005] According to embodiments, the effect of non-uniformity of a universal joint, also known as a U-joint or universal coupling, in a vehicle steering system can be calculated and then compensated for by controlling the power steering unit of the steering system accordingly. In other words, an algorithm is provided for compensating for non-uniformity on an input shaft, for example, introduced by a U-joint on a column shaft of the steering system. In particular, such a function or algorithm can calculate the effect of non-uniformity of the U-joint during steering and compensate for the effect of non-uniformity on the power steering assembly to advantageously eliminate the non-uniform steering feel. Thus, the effect of non-uniformity of the U-joint can be minimized or eliminated, resulting in a uniform feel during vehicle steering. While it may be possible to adjust such universal joint offset angles during end-of-line adjustments to minimize this non-uniformity through mechanical adjustments, this may not completely eliminate the non-uniformity, and perhaps even not sufficiently reduce it, in contrast to the compensation achieved by embodiments.

[0006] A method for controlling a steering system of a vehicle includes: determining uniformity of angular position and velocity of a shaft of a linkage assembly of a steering system, the shaft being coupled to at least another shaft of the linkage assembly by at least one universal joint, the uniformity being determined using at least one sensor signal from at least one sensor of the steering system for sensing rotation of the shaft when steering torque is input by a driver of the vehicle, the angular position and velocity of the shaft being ascertained from the at least one sensor signal; generating a control signal for controlling at least one actuator of a power steering assembly of the steering system, the control signal being generated to include a control parameter defining a correction torque for adjusting a torque provided by the at least one actuator to the linkage assembly in response to the degree of uniformity; Includes.

[0007] The vehicle may be a motor vehicle, such as a utility vehicle or commercial vehicle, e.g., a truck or bus. The method or method steps may be performed using a controller having means therefor. The uniformity may represent variations in the angular position and velocity of the shaft as a function of the rotational angle of the shaft and / or over time. The shaft may be a steering column, a steering shaft, or may be coupled to a steering column or steering shaft of a steering system. The at least one universal joint may be a Cardan joint. The at least one sensor signal may directly or indirectly represent the angular position and velocity or rotational angle of the shaft. For example, the steering system may include two or more sensors for reading angular velocity and shaft position or steering shaft position. A control signal having a control parameter may be used to control at least one actuator, thereby applying a correction torque in addition to the torque provided to the linkage assembly, resulting in an adjusted torque. The correction torque may be calculated to equalize, cancel, or compensate for variations in the angular position and velocity of the shaft.

[0008] According to one embodiment, the determining step may be performed once to determine the static uniformity. Here, the generating step may be performed iteratively using the static uniformity. In particular, the generating step may be performed iteratively using the static uniformity when a steering torque is input by the vehicle driver. Such an embodiment offers the advantage that U-joint non-uniformity can be compensated for by a simple, fast, and reliable process with reduced computational overhead.

[0009] According to another embodiment, the determining step may be performed iteratively to determine a dynamic uniformity. Here, the generating step may be performed iteratively using the dynamic uniformity. In particular, the generating step may be performed iteratively using the dynamic uniformity when a steering torque is input by the vehicle driver. Such an embodiment offers the advantage that U-joint non-uniformity may be compensated for in a particularly reliable and accurate manner, also taking into account potential changes in U-joint behavior over time.

[0010] According to the previous embodiment, in the determining step, the dynamic uniformity may be stored and updated with each repeated execution of the determining step. Such an embodiment offers the advantage of being able to keep track of potential changes in U-joint behavior over time, resulting in the dynamic uniformity being continuously kept up to date to reflect the current behavior of at least one U-joint.

[0011] According to one embodiment, the method may include receiving at least one sensor signal from at least one sensor via an input interface. Such an embodiment presents the advantage that the at least one sensor signal can be reliably acquired.

[0012] According to one embodiment, the method may include outputting a control signal to the at least one actuator via the output interface. Such an embodiment presents the advantage that the at least one actuator may be reliably controlled by the control signal.

[0013] The method or steps of the method may be performed using a controller. Thus, the method may be performed to control an embodiment of a steering system described below.

[0014] The approach presented herein also provides a controller configured to execute, control or perform the steps of the method variants presented herein in corresponding means or units. The underlying object of the invention can also be achieved quickly and efficiently by this embodiment of the invention in the form of a controller.

[0015] For this purpose, the controller may include at least one processing unit for processing signals or data, at least one storage unit for storing signals or data, at least one interface with at least one sensor or actuator for reading sensor signals from at least one sensor or outputting control signals to the actuator, and / or at least one communication interface for reading or outputting data incorporated in a communication protocol. The processing unit may be, for example, a signal processor or a microcontroller, and the storage unit may be a flash memory, an EPROM, an EEPROM, or a magnetic storage unit. The communication interface may be configured to read or output data wirelessly and / or wired, and a communication interface that can read or output data via a line may, for example, electrically or optically read this data from or output it to a corresponding data transmission line.

[0016] The controller may be a technical device that processes the sensor signals and outputs control and / or data signals accordingly. The controller may include an interface that may be configured as hardware and / or software. If configured as hardware, the interface may be part of a so-called system ASIC that includes various functions of the controller. However, it is also possible for the interface to be a separate integrated circuit or to consist at least partially of separate components. If configured as software, the interface may be, for example, a software module that resides on a microcontroller together with other software modules.

[0017] The steering system of the vehicle a linkage assembly having two or more shafts and one or more universal joints connecting the shafts; at least one sensor for sensing rotation of one of the shafts; a power steering assembly having at least one actuator; An embodiment of a controller as described herein, wherein the controller is communicatively connected to at least one sensor and at least one actuator; Equipped with.

[0018] The steering system, or more particularly the operation of the steering system, may be controlled by a controller, the controller comprising means for carrying out the steps of an embodiment of the method described herein.

[0019] It is also advantageous to be programmed by a computer program product or program code, which may be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, a hard drive memory or an optical memory, and which is used in particular to execute, perform / control the steps of the method according to one of the aforementioned embodiments when the program product or program is run on a device, such as a computer or a controller. Embodiments of the techniques presented herein are explained in more detail in the following description with reference to the figures. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a steering system according to an embodiment of the present invention; [Figure 2] 1 shows a flowchart of a method for controlling a steering system of a vehicle, according to one embodiment of the present invention.

[0021] In the following description of preferred embodiments of the present invention, the same or similar reference numerals will be used for elements that act in a similar manner as shown in the various figures, and repeated descriptions of these elements will be omitted.

[0022] 1 is a schematic diagram of a vehicle 100 including a steering system 110 according to one embodiment of the present invention. The vehicle 100 may be a utility vehicle or commercial vehicle, such as a truck. The steering system 110 includes a linkage assembly 120, at least one sensor 130, a power steering assembly 140, and a controller 150.

[0023] Linkage assembly 120 includes a rotatably disposed shaft 122, at least another rotatably disposed shaft 124, and at least one universal joint 126, particularly a Cardan joint, for coupling shaft 122 to at least one other shaft 124. At least one universal joint 126 is also referred to as a U-joint or universal coupling. Shaft 122 of linkage assembly 120 and at least one other shaft 124 are mechanically coupled to each other by at least one universal joint 126. In particular, shaft 122 is a steering column or is coupled to a steering column of steering system 110.

[0024] At least one sensor 130 of steering system 110 is constructed and arranged to sense rotation of shaft 122. At least one sensor 130 is also configured to provide at least one sensor signal 135 that represents, or from which, the angular position and velocity of shaft 122 can be ascertained. According to one embodiment, steering system 110 may include two or more sensors 130 for reading the angular velocity and position of shaft 122 or a steering shaft.

[0025] The power steering assembly 140 includes at least one actuator 142. The power steering assembly 140 is coupled to the linkage assembly 120. The actuator 142 is configured to provide a torque to the linkage assembly 120.

[0026] The controller 150 is communicatively connected to the at least one sensor 130 and the actuator 142 of the power steering assembly 140. The controller 150 is configured to control the steering system 110. To this end, the controller 150 comprises a means for determining 154 and a means for generating 156. According to the illustrated embodiment, the controller 150 also comprises an input interface 152 and an output interface 158.

[0027] Controller 150 is configured to receive at least one sensor signal 135 from at least one sensor 130 via input interface 152. Means for determining 154 is configured to use the at least one sensor signal 135 from the at least one sensor 130 to determine uniformity 155 of the angular position and velocity of shaft 122 of linkage assembly 120 when a steering torque is input by a driver of vehicle 100. Optionally, means for determining 154 is configured to ascertain the angular position and velocity of shaft 122 from the at least one sensor signal 135. Means for determining 154 is configured to pass uniformity 155 to means for generating 156.

[0028] Generating means 156 is configured to generate a control signal 157 for controlling at least one actuator 142 of power steering assembly 140 in response to uniformity 155. Generating means 156 is configured to generate control signal 157 to include a control parameter defining a corrective torque for adjusting the torque provided by actuator 142 to linkage assembly 120 in response to uniformity 155. Controller 150 is configured to output control signal 157 to actuator 142 via output interface 158. In this manner, the effects of U-joint non-uniformity may be compensated for, minimized, and / or eliminated.

[0029] 2 shows a flowchart of a method 200 for controlling a steering system of a vehicle, according to one embodiment of the present invention. The steps of the method 200 for controlling can be performed by the controller of FIG. 1 or a similar controller. The method 200 can be performed to control the steering system of FIG. 1 or a similar steering system. The method 200 for controlling includes a determining step 254 and a generating step 256.

[0030] In a determining step 254, uniformity of angular position and velocity of a shaft of a linkage assembly of a steering system is determined. The shaft is coupled to at least another shaft of the linkage assembly by at least one universal joint. In the determining step 254, uniformity is determined using at least one sensor signal from at least one sensor of the steering system for sensing rotation of the shaft when steering torque is input by a vehicle driver. The angular position and velocity of the shaft are ascertained from the at least one sensor signal.

[0031] In a generating step 256, a control signal is generated for controlling at least one actuator of a power steering assembly of the steering system in response to the degree of uniformity. In the generating step 256, the control signal is generated to include a control parameter defining a correction torque for adjusting the torque provided by the at least one actuator to the linkage assembly in response to the degree of uniformity.

[0032] According to one embodiment, determining step 254 is performed once to determine a static uniformity, and generating step 256 is performed iteratively using the static uniformity. Alternatively, determining step 254 is performed iteratively to determine a dynamic uniformity, and generating step 256 is performed iteratively using the dynamic uniformity. Optionally, in determining step 254, the dynamic uniformity is also stored and updated for each iterative execution of determining step 254.

[0033] According to one embodiment, the method 200 for controlling further comprises a step 252 of receiving at least one sensor signal from at least one sensor via an input interface. According to one embodiment, the method 200 for controlling also comprises a step 258 of outputting the control signal generated in the generating step 256 to at least one actuator via an output interface. [Explanation of symbols]

[0034] 100 vehicles 110 Steering System 120 Linkage Assembly 122 Shaft 124 other shafts 126 Universal joint 130 sensors 135 Sensor Signal 140 Power steering assembly 142 Actuator 150 Controller 152 Input Interface 154 Means for Determining 155 Uniformity 156 Means of Generation 157 Control Signals 158 Output Interface 200 Ways to Control 252 Receiving Steps 254 Decision Steps 256 Generation Steps 258 output steps

Claims

1. A method (200) for controlling a steering system (110) of a vehicle (100), said method (200) comprising: determining uniformity of angular position and velocity of a shaft of a linkage assembly of the steering system, the shaft being coupled to at least another shaft of the linkage assembly by at least one universal joint, the uniformity being determined using at least one sensor signal from at least one sensor of the steering system for detecting rotation of the shaft when a steering torque is input by a driver of the vehicle, the angular position and velocity of the shaft being ascertained from the at least one sensor signal; generating (256) a control signal (157) for controlling at least one actuator (142) of a power steering assembly (140) of the steering system (110), the control signal (157) being generated to include a control parameter defining a correction torque for adjusting a torque provided by the at least one actuator (142) to the linkage assembly (120) in response to the degree of uniformity (155); A method (200) comprising:

2. 2. The method (200) of claim 1, wherein the determining step (254) is performed once to determine a static uniformity (155), and the generating step (256) is performed iteratively using the static uniformity (155).

3. 2. The method (200) of claim 1, wherein the determining (254) is performed iteratively to determine a dynamic uniformity (155), and the generating (256) is performed iteratively using the dynamic uniformity (155).

4. 4. The method (200) of claim 3, wherein the dynamic uniformity (155) is stored and updated in the determining step (254) with each repeated execution of the determining step (254).

5. The method (200) of any one of claims 1 to 4, comprising receiving (252) the at least one sensor signal (135) from the at least one sensor (130) via an input interface (152).

6. The method (200) of any one of claims 1 to 5, comprising the step of outputting (258) the control signal (157) to the at least one actuator (142) via an output interface (158).

7. A controller (150) comprising means (154, 156) for carrying out the steps of the method (200) of any one of claims 1 to 6.

8. A steering system (110) for a vehicle (100), comprising: a linkage assembly (120) having a shaft (122), at least another shaft (124), and at least one universal joint (126) connecting said shafts (122, 124); at least one sensor (130) for sensing rotation of said shaft (122); a power steering assembly (140) having at least one actuator (142); 8. The controller (150) of claim 7, wherein the controller (150) is communicatively coupled to the at least one sensor (130) and the at least one actuator (142); A steering system (110) comprising:

9. A computer program comprising instructions that, when said program is executed by a computer, cause said computer to carry out said steps of the method (200) of any one of claims 1 to 6.

10. A computer readable data carrier storing a computer program according to claim 9.

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