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DE-102024132750-A1 - Device and method for determining parameters of a steering wheel

DE102024132750A1DE 102024132750 A1DE102024132750 A1DE 102024132750A1DE-102024132750-A1

Abstract

The invention relates to a device (100) for determining a steering wheel angle (70) and/or a tilt angle (80) of a steering wheel (300) of a vehicle (250) positioned at a measurement location, comprising at least one image acquisition device (150) that generates a point cloud (400) representing the steering wheel (300), at least one positioning device (130) for positioning the at least one image acquisition device (150) at at least one measurement position (140) relative to the steering wheel (300), and an evaluation unit (190) that evaluates the point cloud (400) captured by the at least one image acquisition device (150), wherein at least one measurement location is assigned a defined measurement location coordinate system (101). Furthermore, the invention relates to a test bench (200) with such a device (100) and a method for determining a steering wheel angle (70) and/or a tilt angle (80) of a steering wheel (300).

Inventors

  • Rainer Weisgerber
  • Thomas Engel
  • Marc Ney

Assignees

  • Dürr Assembly Products GmbH

Dates

Publication Date
20260513
Application Date
20241109

Claims (19)

  1. Device (100) for determining a steering wheel angle (70) and/or a tilt angle (80) of a steering wheel (300) of a vehicle (250) positioned at a measurement location, comprising at least one image acquisition device (150) that generates a point cloud (400) representing the steering wheel (300), at least one positioning device (130) for positioning the at least one image acquisition device (150) at at least one measurement position (140) relative to the steering wheel (300), and an evaluation unit (190) that evaluates the point cloud (400) captured by the at least one image acquisition device (150), wherein at least one measurement location is assigned a defined measurement location coordinate system (101).
  2. Device according to Claim 1 , wherein a calibration gauge (110) for determining the measurement location coordinate system (101) is arranged at least temporarily at the measurement location.
  3. Device according to one of the preceding claims, wherein the at least one positioning device (130) is arranged outside the vehicle (250).
  4. Device according to one of the preceding claims, wherein a positioning device (130) is arranged on each side of the vehicle (250).
  5. Device according to one of the preceding claims, wherein the at least one image acquisition device (150) is pivotable about at least one axis of the measurement location coordinate system (102) and/or displaceable along at least one axis of the measurement location coordinate system (102) and/or is fixedly mounted in the measurement location coordinate system (102).
  6. Device according to one of the preceding claims, wherein a type recognition device (180) for recognizing a vehicle type of the vehicle (250) is provided, in particular wherein the at least one measuring position (140) of the at least one image acquisition device (150) and/or at least one parameter set for evaluating the point cloud (400) can be assigned to the recognized vehicle type.
  7. Test stand (200) with a device (100) according to one of the preceding claims, wherein the test stand (200) is assigned the measurement location coordinate system (101) as a defined coordinate system at the measurement location, in particular wherein the test stand (200) is a chassis adjustment stand.
  8. Method for determining a steering wheel angle (70) and/or a tilt angle (80) of a steering wheel (300) of a vehicle (250) positioned at a measurement location, wherein an image acquisition device (150) generates a point cloud (400) representing the steering wheel (300), wherein a positioning device (130) positions the image acquisition device (150) relative to the steering wheel (300) at at least one measurement position (140), wherein an evaluation unit (190) evaluates the point cloud (400) generated by the image acquisition device (150), wherein at least one measurement location is assigned a defined measurement location coordinate system (101).
  9. Procedure according to Claim 8 , where the point cloud (400) is transformed into the measurement location coordinate system (101).
  10. Procedure according to one of the Claims 8 until 9 , where a calibration is performed for each measuring position (140).
  11. Procedure according to one of the Claims 8 until 10 , wherein at least one measuring position (140) is fixed or wherein the measuring position (140) is moved from a calibration position to the measuring position (140).
  12. Procedure according to one of the Claims 8 until 10 , wherein at least one measurement position (140) is dynamically set, in particular wherein a calibration is performed and a conversion to different measurement positions (140) is carried out by a coordinate transformation from the coordinate system (104) of the image acquisition device (150) to the measurement location coordinate system (101).
  13. Procedure according to one of the Claims 8 until 12 , wherein a type recognition is performed to identify a vehicle type of the vehicle (250), in particular wherein the at least one measuring position (140) of the image acquisition device (150) and/or at least one parameter set for evaluating the point cloud (400) is assigned to the identified vehicle type.
  14. Procedure according to one of the Claims 8 until 13 , wherein an evaluation procedure is carried out in which distinctive features (302, 304, 306, 308) of the steering wheel (300) in the point cloud (400) of the steering wheel (300) are analyzed, the position of which on the steering wheel (300) is specified, and the angle and inclination of which are derived in the measurement location coordinate system (101) by comparison with the specified positions.
  15. Procedure according to one of the Claims 8 until 14 , whereby an evaluation procedure is carried out, in which a comparison is made between the point cloud (400) of the steering wheel and an existing master steering wheel with known steering angle and known tilt angle, and from a difference determined in the comparison the steering angle (70) and the tilt angle (80) of the steering wheel (300) are derived.
  16. Procedure according to one of the Claims 8 until 15 , wherein an evaluation procedure is carried out in which symmetrical features and their position on the steering wheel (300) are used on the basis of the point cloud (400), wherein the steering wheel angle (70) is derived from a required rotation of the point cloud (400) in which the features lie on a horizontal (60).
  17. Procedure according to one of the Claims 8 until 16 , wherein an evaluation procedure is carried out in which a master is generated from a CAD model of the steering wheel, with which the point cloud (400) is compared and from a difference determined in the comparison the steering wheel angle (70) and the tilt angle (80) of the steering wheel (300) are derived
  18. Procedure according to one of the Claims 14 until 17 , wherein if a result of the comparison is implausible and/or a number of points in the point cloud (400) is too low and/or a quality criterion is below a permissible threshold, another measurement position (140) is taken.
  19. Procedure according to one of the Claims 14 until 18 , wherein if a result of the comparison is implausible and/or a number of points in the point cloud (400) is too small and/or a quality criterion lies outside a permissible range of values, another evaluation procedure is carried out.

Description

State of the art The invention relates to a device and a method for determining parameters of a steering wheel, in particular a steering wheel angle and/or a steering wheel tilt. Several methods are known for precisely setting the steering wheel angle in vehicle production. These methods involve measuring both the current steering wheel angle and the steering wheel's tilt. From the WO2018059628A1 A device for detecting the steering wheel angle and tilt of a vehicle is known, wherein the device comprises at least two cameras with which the steering wheel is recorded. At least three reference objects are detachably attached to the steering wheel. Based on the recorded images, photogrammetric image processing methods are performed to determine the tilt of the steering wheel and the steering wheel angle. The DE 102013021475 A1 This describes an optical steering angle determination process in which the steering wheel's angle of rotation is measured fully automatically using a camera and an image processing algorithm. A 3D light section sensor projects a predefined spatially or temporally coordinated pattern onto the vehicle's steering wheel using a light projector. A camera captures the projected pattern. A geometric distortion of the captured pattern compared to the projected pattern is determined, and based on these distortions, a 3D model of the steering wheel is created from which the current steering angle is calculated. Prior to determining the current steering wheel angle, comparative data sets are provided, obtained through a calibration measurement. Disclosure of the invention The object of the invention is to create a device for detecting the steering wheel angle and the inclination of the steering wheel of a vehicle, in which the mounting of reference objects on the steering wheel is unnecessary and a high cycle time is possible. Another task is to create a method for recording the steering wheel angle and the tilt of the steering wheel of a vehicle, in which the mounting of reference objects on the steering wheel is eliminated and a high cycle time is possible. The problems are solved by the features of the independent claims. Favorable embodiments and advantages of the invention become apparent from the further claims, the description, and the drawings. A device for determining the steering wheel angle and/or inclination of a vehicle's steering wheel positioned at a measurement location is proposed. The device comprises at least one image acquisition device that generates a point cloud representing the steering wheel, at least one positioning device for positioning the at least one image acquisition device at at least one measurement position relative to the steering wheel, and an evaluation unit that evaluates the point cloud captured by the at least one image acquisition device, wherein at least one measurement location is assigned a defined measurement location coordinate system. The measurement location can be, for example, a test bench, such as a chassis alignment stand, to which a defined coordinate system is assigned via the measurement location coordinate system. Advantageously, the image acquisition device can have a 3D sensor or be designed as such. Camera images are converted into 3D coordinates using methods such as stereophotogrammetry. The basis for the evaluation is a 3D point cloud of the object being measured, which can essentially be generated with any 3D sensor. Advantageously, the positioning device can position the image capture device in such a way that, firstly, the entire steering wheel is captured, and secondly, the image capture device can be set at the steepest possible angle to the steering wheel. In particular, the image capture device or measuring position can be located outside the vehicle. According to a favorable design of the device, a calibration gauge for determining the coordinate system of the measuring location can be arranged at least temporarily at the measuring location. For calibration, a so-called calibration gauge, such as those used on vehicle test benches, can be advantageously employed. This calibration gauge represents a defined measurement object for all 3D sensors, whose position and orientation within the measurement location coordinate system are known. Additionally, a target in the form of a calibration frame can be present, with a measuring surface featuring optical characteristics for aligning the 3D sensor for steering wheel measurement. The position and orientation of this target within the measurement location coordinate system are also known. The coordinate system is known and can be arranged arbitrarily. This makes it possible to transform the 3D measurement data from the image acquisition device into the measurement location coordinate system. With a favorable design of the device, at least one positioning element can be arranged outside the vehicle. Advantageously, no assembly work is required inside the vehicle, which is beneficial for