DE102021113572A1 - Method and device for operating a head-up display system - Google Patents

Abstract

The invention relates to a method for operating a windscreen display system with a display unit and with a control device for driving the display unit, wherein the control device comprises a control unit for controlling functions of the display unit and an image adaptation unit for carrying out a transformation of a display information provided, with the following steps :
- performing a transformation on provided display information in the image adaptation unit in order to obtain a display image;
- performing an inverse transformation of the obtained display image by the control unit with the aim of reconstructing the display information provided;
- checking whether there is an error in the image adjustment unit, an error being detected if the display information provided and the display information obtained by inverse transformation differ from one another;
- when detecting the error in the image adjustment unit, signaling a malfunction of the windscreen display system.

Description

technical field

The invention relates to head-up display devices, in particular reflective display systems such as HUD (Head-up Display) and PHUD (Panorama Head-up Display) for motor vehicles. In particular, the present invention relates to measures for detecting an object located in the optical beam path of the windshield display device.

Technical background

Various forms of head-up display systems are known, such as reflective display systems such as PHUD (Panorama Head-up Display) and projection display systems such as HUD (Head-up Display). Reflective display systems include a display unit located on top of the instrument panel, the display of which is reflected on the inside of the windshield viewable by a vehicle occupant. The display unit is arranged somewhat recessed on the upper side of the instrument panel, so that a direct view of the display surface of the display unit is prevented in order to prevent the user from being dazzled by light falling directly into the eye.

According to legal requirements, it is required for safety-critical displays that they go into a safe state when an error occurs. This safe state should be designed in such a way that the driver immediately recognizes the error in the display system and, if necessary, can shut down the vehicle immediately or stop operating it. If safety-critical and/or legally required displays are relocated from the dashboard to a windscreen display system, the requirement for the safe state to be adopted also applies here.

Due to the curvature and/or inclination of the windscreen in the transverse direction, an image adjustment is necessary for the display of a windscreen display system so that the vehicle occupants can perceive the display image reflected on or via the windscreen without distortion. For this purpose, the display information to be displayed is transformed in an image adaptation unit into a display image that is displayed on the display unit of the windscreen display system. The image adjustment unit has a graphics processor device that is particularly suitable for image processing. If an error occurs in the image adjustment unit, this may not be immediately detectable by a driver. The driver sees an image display that may contain incorrect or illegible information.

Since the faulty display content cannot usually be determined directly by a driver or vehicle occupant, the windscreen display system is not in a safe state by which an error can be detected.

It is an object of the present invention to protect a windscreen display system for a motor vehicle, so that a safe state can be assumed if a fault occurs in an image adjustment unit.

Disclosure of Invention

This object is achieved by the method for operating a windscreen display system in a motor vehicle according to claim 1 and a windscreen display system according to the independent claim.

Further developments are specified in the dependent claims.

• - Durchführen einer Transformation auf eine bereitgestellte Anzeigeinformation in der Bildanpassungseinheit, um ein Anzeigebild zu erhalten;
• - Durchführen einer Rücktransformation des erhaltenen Anzeigebilds durch die Steuereinheit mit dem Ziel, die bereitgestellte Anzeigeinformation zu rekonstruieren;
• - Überprüfen, ob ein Fehler in der Bildanpassungseinheit vorliegt, wobei ein Fehler festgestellt wird, wenn die bereitgestellte Anzeigeinformation und die durch Rücktransformation erhaltene Anzeigeinformation voneinander abweichen;
• - bei Feststellen des Fehlers in der Bildanpassungseinheit, Signalisieren einer Störung des Frontscheiben-Anzeigesystems.

According to a first aspect, a method for operating a windshield display system with a display unit and with a control device for driving the display unit is provided, wherein the control device comprises a control unit for controlling functions of the display unit and an image adaptation unit for carrying out a transformation on a display information provided, with the following steps:

• - performing a transformation on provided display information in the image adaptation unit in order to obtain a display image;
• - performing an inverse transformation of the obtained display image by the control unit with the aim of reconstructing the display information provided;
• - checking whether there is an error in the image adjustment unit, an error being detected if the display information provided and the display information obtained by inverse transformation differ from one another;
• - when detecting the error in the image adjustment unit, signaling a malfunction of the windscreen display system.

Provision can be made for the display unit to at least display when a fault is signaled in the windscreen display system of the display image provided by the image adjustment unit is deactivated.

Furthermore, if no error is detected in the image adjustment unit, the display image provided by the image adjustment unit can be transmitted to the display unit for display.

In particular, the transformation to the provided display information can be carried out in such a way that distortions of a displayed display image that can be perceived by a vehicle occupant due to a curvature and/or inclination of a reflection area are compensated for.

In a windshield display system, display information provided as image information by a higher-level control system is converted into a display image and presented to a driver or other vehicle occupants via a reflection in a reflective area of the windshield. Because of the curvature and/or the transverse inclination of the windshield, particularly in the reflection area, a simple reproduction of the display information would result in distortions, which would make it difficult for the vehicle occupants to perceive the display information. Therefore, a head-up display system typically has an image adjustment unit that typically includes a graphics processor device.

The graphics processor device performs an image transformation on the display information in order to generate a display image (which is distorted compared to the original display information) which can be perceived undistorted by the vehicle occupants after reflection in the curved and/or inclined reflection area of the windscreen. If there is a malfunction in the image adjustment unit, the law requires that the display be set or reset to a predetermined safe state. According to the above method, this safe state is to be achieved by switching off the entire windscreen display system or deactivating the display.

According to the above method, it is now provided to first process the display information using the image adjustment unit in order to provide a display image for display on a display area of the display unit. This display image is transformed with respect to the original display information to allow a vehicle occupant to view the display information undistorted after reflection at the reflective area of the windshield. To ensure the proper functioning of the image adjustment unit, a reverse transformation of the display image provided by the image adjustment unit is carried out in a separate arithmetic unit, in particular in a microprocessor unit of a control unit for the windscreen display system. The result of the inverse transformation is the original display information if the image adjustment unit is working properly.

By comparing the original display information and the inverse-transformed display information, an error in the image adjustment unit can thus be detected. If such an error is detected, the display unit for showing the display image to the vehicle occupants via the reflection area is deactivated, so that the error in the reflection display system becomes obvious to the vehicle occupants, since information that is to be displayed permanently, such as a speed display, is no longer displayed.

According to one embodiment, when an error is detected in the image adjustment unit, the display information can be transformed in the control unit and the resulting display image can be transmitted to the display unit for display instead of the display image provided by the image adjustment unit.

In particular, when the error is detected in the image adjustment unit, one or more additional functions that are executed in the control unit or are provided for execution in the control unit can be deactivated.

According to a further embodiment, it can be provided that the control unit takes over the transformation of the display information if an error in the image adjustment unit has been detected. In this way, the graphic processing of the display information, which should be done in the image adjustment unit, can be carried out in the microprocessor unit of the control unit. This enables emergency operation of the windscreen display system by using the computing capacity of the control unit.

If necessary, the execution of other less safety-critical functions can be deactivated in order to provide sufficient capacities for the calculation in the control unit.

According to one embodiment, the image adjustment unit can be higher than the frequency of performing the inverse transformation in the control unit.

• - eine Anzeigeeinheit
• - eine Bildanpassungseinheit, die ausgebildet ist, um
  • o eine Transformation auf eine bereitgestellte Anzeigeinformation durchzuführen, um ein Anzeigebild zu erhalten und das Anzeigebild bereitzustellen;
• - eine Steuereinheit zum Steuern von Funktionen der Anzeigeeinheit; wobei die Steuereinheit ausgebildet ist, um:
  • o eine Rücktransformation des erhaltenen Anzeigebilds mit dem Ziel durchzuführen, die bereitgestellte Anzeigeinformation zu rekonstruieren;
  • o zu überprüfen, ob ein Fehler in der Bildanpassungseinheit vorliegt, wobei ein Fehler festgestellt wird, wenn die bereitgestellte Anzeigeinformation und die durch Rücktransformation erhaltene Anzeigeinformation voneinander abweichen;
  • o bei Feststellen des Fehlers in der Bildanpassungseinheit eine Störung des Frontscheiben-Anzeigesystems zu signalisieren.

According to another aspect, there is provided a windshield display system for a motor vehicle, comprising:

• - a display unit
• - an image adjustment unit, which is designed to
  • o perform a transformation on provided display information in order to obtain a display image and to provide the display image;
• - a control unit for controlling functions of the display unit; wherein the control unit is configured to:
  • o perform an inverse transformation of the display image obtained with the aim of reconstructing the display information provided;
  • o to check whether there is an error in the image adjustment unit, an error being detected if the display information provided and the display information obtained by inverse transformation deviate from one another;
  • o to signal a failure of the windscreen display system upon detecting the error in the image adjustment unit.

character list

• 1 eine schematische Darstellung eines Frontscheiben-Anzeigesystems in einem Kraftfahrzeug;
• 2 eine Blockdarstellung des Frontscheiben-Anzeigesystems; und
• 3 ein Flussdiagramm zur Veranschaulichung eines Verfahrens zum Betreiben des Frontscheiben-Anzeigesystems der 1 und 2.

Embodiments are explained in more detail below with reference to the accompanying drawings. Show it:

• 1 a schematic representation of a windscreen display system in a motor vehicle;
• 2 a block diagram of the windshield display system; and
• 3 a flowchart illustrating a method for operating the windscreen display system of FIG 1 and 2 .

Description of Embodiments

1 shows a schematic cross-sectional illustration through a motor vehicle with a windshield display system 1. The reflection display system is arranged on a top side of an instrument panel 4 and has a display unit 2, which includes a display surface 3 for displaying a display image. The display unit 2 is arranged on the upper side of the instrument panel 4 below a windscreen 5 .

The display surface 3 is oriented with respect to the windshield 5 so that a display image displayed on the display surface of the display unit 2 is reflected at a lower portion of the inside of the windshield 5 and can be seen in an eye area B by a vehicle occupant. As a result, the orientation of the display unit 2 or its display surface 3 is preferably essentially parallel to the longitudinal and transverse axis of the vehicle or deviates from them by an angle of no more than 0-20°.

The display unit 2 is mounted in a recess 6 of the instrument panel, so that the vehicle occupant cannot look directly at the display surface 3 of the display unit 2 and the vehicle occupants are prevented from being dazzled by direct light from the display surface 3 in the eye area B. Furthermore, the display surface 3 of the display unit 2 is oriented such that a displayed display image is reflected on the inside of the windshield 5 and can be seen by a vehicle occupant in an eye area B as a reflection image on the windshield 5 .

The display unit 2 is preferably designed as a light-emitting display unit, in particular as an LCD display unit or micro-LED display unit, in order to provide a bright display image, so that the reflection generated can be perceived over the corresponding area of the windshield 5 even when the ambient brightness is high.

The windscreen display system 1 also has a control device 7 with a control unit 8 and an image adjustment unit 9 . The control unit 8 includes a microprocessor device for performing functions of the windscreen display system 1. The image adjustment unit 9 includes a graphics processing unit (GPU) which is particularly suitable for processing image information and for carrying out image transformations and the like.

The display unit 2 is in communication with a control unit 8 in order to provide a display image for output via the display unit 2 . Furthermore, the control device 7 receives display information from a higher-level control system 10, which can contain or represent image information for display to the vehicle occupants.

The method carried out in the windscreen display system 1 is explained using the block diagram of FIG 2 and the flowchart of 3 explained in more detail.

In 2 the functional block diagram is shown, in which a piece of display information A to be displayed is provided by the higher-level control system 10, for example by a driver assistance system and the like. In step S1, the display information A is fed to the image adaptation unit 9, which can include, in particular, a graphics processor device in order to carry out an image transformation.

The image transformation serves to compensate for distortions that would occur if the unchanged display information of the display unit 2 were reflected, so that the display unit 2 displays a reflection image that can be perceived as an undistorted display image by the vehicle occupants over the reflection area. For this purpose, the image adjustment unit 9 carries out a transformation which compensates for curvatures and inclinations of the reflection area of the front pane 5 accordingly.

In step S2, the display image E obtained from the image adjustment unit 9 is transmitted to the display unit 2, which displays the display image accordingly. The control unit 8 is also connected to the display unit 2 and is designed to allow or prevent the display of the display image E from the image adjustment unit 9 .

The display image E is also received in a control unit 8 . In step S3, the control unit 8 carries out an inverse transformation of the display image E, so that if the display image E is correct, the original display information can be obtained.

Then, in step S4, the original display information is compared with the display information that has been transformed back. If a discrepancy is found between the display information and the inverse-transformed display image (alternative: yes), the method continues with step S5, otherwise (alternative: no) the process jumps back to step S1.

An error is signaled in step S5. The signaling of the error leads to the display unit 2 being deactivated by the control unit 8 and no display being shown.

In an alternative embodiment, after an error has been detected in the control unit 8, the calculation of the image adjustment unit 8 can also be carried out in the control unit 8. For this purpose, the image adjustment unit 9 is deactivated and the display information A is processed directly in the control unit 8 . The control unit 8 then outputs the display image E to be displayed to the display unit 2 and ignores information and data which are output by the image adjustment unit 9 for display via the display unit 2 .

However, while the image adjustment unit 9 comprises a graphic processor means, the control unit 8 is merely provided with a conventional microprocessor unit. This is less efficient in calculating transformations of image data and is therefore heavily loaded. In the event of an error in the image adjustment unit 9, the transformation of the display information A can thus be carried out in the control unit 8 in an emergency mode. In order to provide sufficient computing capacity to perform this transformation, less safety-critical functions can be deactivated or reduced. Furthermore, when the emergency mode is activated, the driver or vehicle occupants can be signaled accordingly, so that they can drive to a workshop as quickly as possible.

Reference List

1

Windscreen display system

2

display unit

3

display area

4

dashboard

5

windscreen

B

eye area

6

deepening

7

control device

8th

control unit

9

image adjustment unit

10

control system

A

display information

E

display image

Claims (8)

Method for operating a windscreen display system (1) with a display unit (2) and with a control device (7) for driving the display unit (2), the control device (7) having a control unit (8) for controlling functions of the display unit (2 ) and an image adaptation unit (9) for performing a transformation on a provided item of display information (A), with the following steps: - performing (S2) a transformation on a provided item of display information (A) in the image adaptation unit (9) in order to obtain a display image ; - Carrying out (S3) an inverse transformation of the display image (E) obtained by the control unit with the aim of reconstructing the provided display information (A); - Checking (S4) whether there is an error in the image adjustment unit (9), an error being detected if the display information (A) provided and the display information obtained by inverse transformation deviate from one another; - If the error is detected in the image adjustment unit (9), signaling (S5) a fault in the windshield display system (1). procedure after claim 1 , wherein in the event of a signaled fault in the windshield display system (1), the display unit (2) is deactivated at least to display the display image (E) provided by the image adjustment unit (9). procedure after claim 1 or 2 , wherein if no error is detected in the image adjustment unit (9), the display image provided by the image adjustment unit (9) is transmitted to the display unit (2) for display. Procedure according to one of Claims 1 - 3 , wherein the image adjustment unit (9) comprises a graphics processor device and the control unit (8) comprises a microprocessor device, wherein if an error is detected in the image adjustment unit (9), the display information is transformed in the control unit (8) and the resulting display image is displayed instead of that from the Image adjustment unit (9) provided display image is transmitted to the display unit (2) for display. procedure after claim 4 , wherein when the error is detected in the image adjustment unit (9), one or more other functions that are executed in the control unit (8) or are provided for execution in the control unit (8) are deactivated. Procedure according to one of Claims 1 - 5 , wherein the frequency of providing the display image by the image adjustment unit (9) is higher than the frequency of performing the inverse transformation in the control unit (8). Procedure according to one of Claims 1 - 6 , wherein the transformation to the provided display information is carried out in such a way that distortions of a displayed display image that can be perceived by a vehicle occupant due to a curvature and/or inclination of a reflection area are compensated for. Windscreen display system (1) for a motor vehicle, comprising: - a display unit (2), - An image adjustment unit (9), which is designed to o perform a transformation on provided display information in order to obtain a display image and to provide the display image; - a control unit (8) for controlling functions of the display unit (2), the control unit (8) being designed to: ◯ perform an inverse transformation of the display image obtained with the aim of reconstructing the display information provided; ◯ to check whether there is an error in the image adjustment unit (9), an error being detected if the display information provided and the display information obtained by inverse transformation deviate from one another; ◯ upon detection of the error in the image adjustment unit (9), to signal a malfunction of the windscreen display system (1).

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