Exemplary embodiments of the invention relate to a method and a device for monitoring a display content.
Since 2011, the safety standard ISO 26262 has applied for the development of motor vehicles, in particular passenger motor vehicles.
Specific requirements arise from this safety standard, which make it necessary for some warning lights and displays to be implemented “safely” in instrument clusters and for them to be allocated with an Automotive Safety Integrity Level (ASIL).
These displays must be visible to the driver after a guaranteed period of time in order for the driver to be able to react appropriately. With full display instrument clusters, these displays are implemented by graphical display elements.
Here, a potential occurrence of safety-critical defects must be avoided. Potential safety-critical hardware/software defects in full-display instrument clusters are:
The safety of the displays according to ISO 26262 is achieved by a hardware/software path that loads up the icons to be displayed when an activation request by CAN BUS is received, and displays them at the pre-determined display positions. A second hardware/software path also evaluates the activation request, but also monitors, by way of a checksum comparison, whether the requested display actually also is and remains visible within the predetermined time period at the position provided. Here, a checksum of the current display is calculated and compared with a checksum stored during the development of the control device.
In known methods, the checksums are determined with the aid of pre-defined image regions. Here, a checksum is calculated by way of the pixel colors within the image region. This checksum becomes clear once the image region is sufficiently large that the shape and color of the icon produces a clear pixel pattern.
What is disadvantageous about this solution is that not only the respective icon, but also the background thereof is included in the checksum formation. Therefore, the icon and its background have to be implemented completely statically, since otherwise the checksum comparison would fail in the event of a changing background or animations.
This limitation is a serious problem for an attractive design of full-display instrument clusters, since it makes different color worlds and animations partially impossible.
Accordingly, exemplary embodiments are directed to guaranteeing safe displays by avoiding the aforementioned limitations.
According to an embodiment a method for monitoring a display content that is to be displayed on a display device of a vehicle is provided. Here, it is provided that the display content has an image symbol and a background. A monitoring region is determined by inserting an encryption element within the image symbol and outside the background into the data having the display content to be displayed. The data having the display content to be displayed is transferred to the display device: by using the encryption element in the data having the display content to be displayed, said data having been transferred to the display device, it is determined whether or not the image symbol is displayed without any defects.
Exemplary embodiments are also directed to a device having equipment set up for carrying out the method.
Accordingly, exemplary embodiments provide for monitoring of safety-critical display content using invisible encryption elements, for example in the form of watermarks.
This can advantageously be in accordance with the safety standard ISO 26262.
The checking region or monitoring region is reduced to a very small region, for example 4×4 pixels, such that it is located entirely within a safety-critical image symbol or display element. Since no clear differentiation of the display elements from their outline would be possible any more, at least one invisible and clear encryption element is stored in the form of a watermark on the display element to be monitored.
Therefore, display content can be monitored for its visibility and correct display without limitations in the design of backgrounds or animations. This is particularly advantageous during the use of combined display units in the field of vehicles. According to this, the display instrument according to the invention, for example in the design of an instrument cluster, in particular in a full-display instrument cluster, can be installed in a vehicle.
The visibility of the display elements can, accordingly, be monitored without interdependency with the background, such that a maximum degree of design freedom is enabled. Highly attractive and varying display designs can therefore be incorporated and, at the same time, safety-critical applications and warning lights can be implemented in display instruments.
Further advantages, features and details of the invention result from the following description of a preferred exemplary embodiment as well as with the aid of the drawing. The features and combinations of features specified in the description above and the features and combinations of features specified in the description of the figures and/or in the figures only below can be used not only in the combination specified in each case, but also in other combinations or on their own without exceeding the scope of the invention.
Here are shown:
In order to solve the limitations in the design of the backgrounds 15, 25, 35, the respective monitoring regions 12, 22, 23 are reduced so significantly compared to the monitoring regions 11, 21, 31 from
The significant reduction of the monitoring regions 12, 22, 32 in
Therefore, in addition to the reduced monitoring regions 12, 22, 32, encryption elements 13, 23, 33 in the form of watermarks are used. Clear identification of the safety-critical display contents or display elements 10, 20, 30 can be implemented by means of clear watermarks 13, 23, 33 that are imprinted respectively onto the image symbols 14, 24, 34 at the monitored regions 12, 22, 32. The watermarks 13, 23, 33, as depicted by way of example in
From this, the advantages arise that safety-critical displays in display panels are able to be depicted without having to acquiesce to limitations in the design of non-safety-critical content such as background color. Color changes, animations and other dynamic changes can be implemented in order to provide the user with attractive displays that are still compliant with ISO 26262.
Although the invention has been illustrated and described in detail by way of preferred embodiments, the invention is not limited by the examples disclosed, and other variations can be derived from these by the person skilled in the art without leaving the scope of the invention. It is therefore clear that there is a plurality of possible variations. It is also clear that embodiments stated by way of example are only really examples that are not to be seen as limiting the scope, application possibilities or configuration of the invention in any way. In fact, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete manner, wherein, with the knowledge of the disclosed inventive concept, the person skilled in the art is able to undertake various changes, for example, with regard to the functioning or arrangement of individual elements stated in an exemplary embodiment without leaving the scope of the invention, which is defined by the claims and their legal equivalents, such as further explanations in the description.
Number | Date | Country | Kind |
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10 2015 004 914.3 | Apr 2015 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2016/000420 | 3/9/2016 | WO | 00 |