DE102012020608B4 - Car with an input device for handwriting recognition - Google Patents

Abstract

The invention relates to a method for operating an input device (10) for an electronic device of a motor vehicle, wherein a character track (28) of a user (26) is detected by a detection device (14, 30) while the latter inputs the character track (28) of a character (42) or a group of characters on an input surface (14) of the detection device (14, 30), and by a handwriting recognition device (40) character recognition to the detected character track (28) is performed and by a display device (12) a display to a result (42) of recognition is generated. The invention is based on the problem of enabling a clear operation of the device by means of a handwriting recognition in a motor vehicle. For this purpose, the display device (12) also displays the character track (28) after the character recognition has been carried out.

Description

The invention relates to a motor vehicle with a handwriting recognition system for operating an electronic device of the motor vehicle, for example a navigation system or an infotainment system. The invention also includes an input device with a handwriting recognition and a method for operating the input device. By means of the input device, for example, in a navigation database, a place name can be searched for by manually drawing letters on an input area.

Such an input device is for example from the EP 1 475 693 A2 known. Thereafter, the character trace of a single character drawn by a user is detected by a detection means while the user draws the character trace on the input surface such as a touch screen. On the basis of the character track, a character recognition is then carried out by a handwriting recognition device, and thus the character intended by the user is recognized, in this case the letter. The character track displayed on a screen is then replaced by the recognized character. In this way, the user can enter by hand letter by letter the beginning of a place name, which is then automatically completed on the basis of a database search, if possible, if the place name can be determined uniquely based on the previously entered letters.

The problem with using handwriting recognition systems is that a character track can not always be uniquely assigned to a particular character. If, for example, the user draws a vertical line "I", then this line may be the capital letter I, the lowercase letter I or the number 1. A handwriting recognition system then outputs as the recognition result the character that most closely matches the character track. If the user has written uncleanly and therefore the recognition result is incorrect, in the case described above the input of the user may automatically be supplemented to a place name which the user did not mean at all. The user is then not clear why the input device suddenly displays this wrong place name.

In the US 2009/0256808 A1 is described a handwriting recognition system for a smartphone. The handwriting recognition system can handwrite an e-mail. A character track of the user is displayed on the screen of the smartphone. In addition, the text recognized by the handwriting recognition system from the character track is displayed in a separate line of text.

The invention is based on the problem of enabling a clear operation of the device by means of a handwriting recognition in a motor vehicle.

The object is achieved by a method according to claim 1, an input device according to claim 6 and a motor vehicle according to claim 7. Advantageous developments of the invention are given by the dependent claims.

According to the inventive method, the actual character track is not immediately deleted on the display device and replaced by the recognized letter. Instead, the original manuscript is initially left standing. It becomes so clear to the user with which of the characters entered that handwriting recognition has encountered difficulties such that the character track is ambiguous and therefore several different recognition results are possible. The inventive method provides accordingly, by a display device, such as a screen, after performing the character recognition and the character track itself is displayed.

At the same time, ambiguities in the recognition of the character trace are taken into account. The inventive method provides according to a development accordingly, by the recognition device, that is, a character recognition device for recognizing handwritten characters, to an ambiguous character track not only that He detection result (ie, for example, a letter or a number) to determine which is the largest match with the Character trace, but several different recognition results. In the above example, therefore, the capital letter I as well as the lowercase letter I, the number 1 and possibly the capital letter J are determined as a recognition result in each case for a vertical stroke "I". The display device is then designed to simultaneously display both the detected character trace itself and a hit list formed on the basis of the different recognition results.

The hit list can, for example, directly include the respective recognition results. However, it can also include the current recognition result together with the previously entered characters. The user can enter such a word eg character by character, whereby in each case due to ambiguities of the individual character tracks all those letter sequences are displayed in the hit list, which refer to the read the entered character tracks. For example, the input of the two character tracks for "O" and "I" could lead to a hit list with several list entries, such as: "Ol", "01", "ol", "OJ" etc.

However, the hit list is not formed directly from the recognition results themselves. Instead, at least one database entry is searched by means of a database search in at least one database by a search device for each of the different recognition results. In other words, after the recognition of a new character track, a location name search, for example, is carried out in each case in a navigation database, for example, or refined after the input of further characters. The hit list is then formed from the database entries found for the different recognition results. In the hit list, those word components are preferably emphasized in the individual hits (for example, in color or by underlining), to which the system has matched using the handwriting input, that is, has recognized a match.

A single character track does not have to stand for a whole word. The character recognition can be carried out after entering in each case one character track of a single character, ie a letter, a number or even a special character (for example,; -!?), Or else a character track of a character group of several characters. This character group does not have to be a complete word. So the user can e.g. draw three characters one after the other as a character track before character recognition starts for that character track. The character track does not have to consist of just a single line.

The user can thus enter, for example, a word or telephone number, whereby the hit list is changed after entering each character track. In other words, the detection device preferably records a plurality of character tracks one after the other and in this case first performs a character recognition for the current character track after the detection of each of the character tracks and then specifies the database search on the basis of the recognition results of all previously recorded character tracks, i. the number of found database entries is reduced as far as possible with each further entered character. By further specifying the database search after entering each character track, the user advantageously recognizes which character is recognized as ambiguous by the handwriting recognition system.

According to one embodiment of the method, the database search is started in each case as soon as a predetermined criterion has been met after the detection of the character track. For example, it may be provided to start the database search as soon as the user has lifted a drawing instrument, for example a finger or a stylus, off the input surface. Another suitable criterion is that the character trace must have remained unchanged for a predetermined period of time. The use of a criterion for starting the database search has the advantage that it can be determined by suitable criteria when the display generated by the display device is changed. If this happens too early, the user is irritated when drawing the character track.

In the context of the invention, characters on the input surface do not mean that the user draws a stroke with a color. Rather, it is sufficient for the user, for example, to swipe with one finger over a touch-sensitive input surface of a touchpad, a touch screen or a comparable sensor arrangement which captures, for example capacitively or optically, the path or trajectory traveled by, for example, the fingertip.

In the search in the database, unlike in the prior art, it is not absolutely necessary to assume that the entered characters form the beginning of a word or of a telephone number, or generally of a database entry. Although the matching criterion which is used in the search in the database can also specify such a prefix search, additionally or alternatively, an infix search (the previously entered character string can also be within a word) and / or a suffix search (the string describes the end of the word). In connection with the method according to the invention it has been found that it is easily possible to increase the search range in a database by an infix search and a suffix search by a multiple without a user being confused by a large number of database entries found. Furthermore, by displaying the original handwriting on the display device, even in the case of ambiguous character traces, the user can see how the information displayed in the hit list has resulted.

In order to further develop a handwriting recognition device known per se from the prior art in such a way that it can determine a plurality of different recognition results for a single character track, an embodiment of the method according to the invention provides for multiple possible handwriting recognition devices Detection results in each case to determine a recognition value, which is a measure represents a match of the character trace with a respective, possible recognition result. Such a recognition value is a known quantity in connection with the pattern recognition. For example, in a handwriting recognition based on hidden Markov models (HMM), a likelihood value or a log likelihood value can be determined. According to the prior art, the handwriting recognition system then outputs that possible recognition result as the final result for which the measure indicates the greatest match.

The recognition values for several possible recognition results are now made accessible. Thus, it is possible to search specifically for those possible recognition results whose recognition value indicates that the match is at least greater than a predetermined minimum. In a character track for example, a letter can not only for the most similar letter, but it can be determined as recognition result, the two or three most similar letters that have the largest match with the given character track. In the above examples, therefore, not only, for example, the capital letter I, but also the lower case letter I and the number 1 would be output to a vertical stroke I if one selected the three most similar recognition results.

As already mentioned above, the invention also includes an input device for an electronic device of a motor vehicle. This is set up to carry out an embodiment of the method according to the invention.

The motor vehicle according to the invention, which is also already mentioned, is distinguished by an embodiment of the input device according to the invention which is provided in the motor vehicle. In the motor vehicle according to the invention, the input device is preferably designed for operating a navigation device and / or an infotainment system and / or a mobile radio system of the motor vehicle. Thus, a user of the motor vehicle advantageously via the input device in a navigation database, for example, a place name, in a infotainment system, for example, pick a song and mobile phone in a mobile phone number or the name of an address book by handwritten input of at least one component of the search term.

In the following, the invention will be explained again in more detail with reference to a concrete embodiment.

For this purpose, the only figure (Fig.) Shows an input device 10 , which represents a preferred embodiment of the input device according to the invention. The input device 10 can for example be installed in a motor vehicle, especially a passenger car. The input device 10 can be a display device 12 For example, a screen with associated electronic control, an input surface 14 , For example, a touchpad or based on capacitive or optical detection character field, and a controller 16 include. Instead of the individual control device shown in the figure 16 can also be provided a composite of multiple control devices. The control unit 16 may for example be part of an infotainment system of the motor vehicle.

In the example underlying the figure, a user wants to set a navigation destination for an upcoming trip. He would like to do this from a navigation database 18 pick a place name of the navigation destination. The navigation database 18 can in the control unit 16 be provided. The navigation database 18 can do this with other databases, such as a music database 20 and / or an address / telephone number database 22 be provided. To search for the place name, the user deletes with one finger 24 a hand 28 over the input area 14 and draw a character trace 28 on the input surface 14 , The sensors of the input surface 14 capture the character trace 28 and transmit corresponding signals to an evaluation device 30 of the control unit 16 which evaluate the signals. The evaluation device 30 and the input area 14 together form a detection device for the character trace 28 ,

On the display 12 becomes an indicator while typing 32 generates a handwriting field 34 may include, in which an image 28 ' the character trace 28 together with pictures 36 ' . 38 ' may be represented by previously recorded character tracks in the order of their input. The of the evaluation device 30 from the sensor signals of the touchpad 14 generated data of the current character track 28 are not only to the display device 12 but also to a handwriting recognition 40 transfer.

The handwriting recognition 40 leads to the current character track 28 a handwriting recognition and recognizes in the present example in the character track 28 the letter "N". The recognized letter forms the unique recognition result 42 the handwriting recognition to the character trace 28 , The recognition result 42 is sent to a search facility 44 forwarded for a database search.

The search facility 44 is with the databases 18 . 20 . 22 coupled and designed to be in the databases 18 . 20 . 22 to find at least one database entry which has an item associated with a search string 46 matches, which is formed from the previously recognized characters. The search string 46 is in the example shown from the current recognition result 42 and the recognition results recognized from the preceding character tracks 48 . 50 educated. In the situation shown in the figure, the letters "MUN" have already been recognized. In the present example, the database search is configured exclusively in the navigation database 18 to search. The database search 44 finds a variety of database entries that match the search string 46 , here so "MUN", according to a set search criterion, here a prefix search, match.

The found database entries 52 be from the search engine 44 to the display device 12 transfer. The display device 12 puts the found database entries 52 as a hit list 54 In the event that the searched place name is among the found and in the hit list 54 displayed database entries 52 is located, the user can select the desired place name directly, eg by tapping, so that by a control module 56 the navigation device of the motor vehicle can be configured according to the navigation based on the selected place name. Otherwise, the user can enter another character track to refine the database search.

In the illustrated components of the controller 16 , ie the evaluation device 30 , handwriting recognition 40 , the search facility 44 and the control module 56 they may be, for example, program modules which are part of an operating program of the control unit 16 could be. In handwriting recognition 40 it may be a recognition algorithm known per se from the prior art. The database search by the search facility 44 can also be realized by means of a search algorithm known per se.

The example shows how, taking into account the context (here a search exclusively in the navigation database 18 Furthermore, an intuitive to-understand display can be generated in which the user is illustrated how an input device interprets his handwritten input. Simple and faster inputs are possible because no manual disambiguation by the user is necessary, ie the user · does not have to pay attention to whether the system has actually recognized the letter entered by him. An automatic disambiguation through the handwriting recognition 40 is also not necessary. For example, if the user enters a zero ("0") and is typed by handwriting recognition 40 in addition to the zero ("0") also a capital letter O recognized, so can by the database search 44 both on the basis of a search string with a 0 and based on a search string with a capital letter O the search is performed and the database entries thus found in the hit list 46 be recorded. By preserving the fingerprint display even after performing character recognition, the user has clear and unambiguous feedback on what he has entered. The display of the character track makes it understandable to the user why, for example, entries with a 1, a capital letter I and the capital letter J appear as a result in a hit list when he draws a vertical bar I. Also, an acoustic feedback is not necessary, so that can also be dispensed with.

Claims (8)

Method for operating an input device (10) for an electronic device of a motor vehicle, wherein: - a character track (28) of a user (26) is detected by a detection device (14, 30) while the latter is input to the character track (28) for inputting a character (42) or a character group on an input surface (14) of the detection device (14, 30) draws, - by a handwriting recognition device (40) character recognition to the detected character track (28) is performed, and - by a display device (12) a display to a result (42) of the recognition is generated, characterized in that the character track (28) is displayed by the display device (12) after performing the character recognition and by the handwriting recognition device (40) to the character track (28) several different recognition results (42) and by a search device (44) by means of a database search (44) in at least one date nbank (18, 20, 22) is searched for each of the different recognition results (42) at least one database entry (52), which meets a match criterion with respect to the recognition result (42), and from found database entries (52) a hit list (54) is formed and the hit list (54) is displayed by the display means (12) as the result of the recognition. Method according to Claim 1 in which the database search is started as soon as a predetermined criterion is met after the acquisition of the character trace (28), in particular as soon as the user (26) a drawing instrument (24) has lifted from the input surface (14) and / or the character trace (28) has remained unchanged for a predetermined period of time. Method according to one of the preceding claims, wherein a plurality of character tracks (28) are detected in succession by the detection device (14, 30) and in this case after the detection of each of the character tracks a) a character recognition is performed for the current character track (28) and b) on the Based on recognition results (42, 48, 50) determined for a plurality of previously recorded character traces (28), the database search is specified. Method according to one of the preceding claims, wherein the match criterion specifies a prefix search and / or infix search and / or suffix search. Method according to one of the preceding claims, wherein a recognition value is determined by the handwriting recognition device for a plurality of possible recognition results, which represents a measure for a match of the character trace with the possible recognition result, and as the different recognition results those possible recognition results are selected whose recognition value indicates that the match is greater than a predetermined minimum. Input device (10) for an electronic device of a motor vehicle, which is adapted to carry out a method according to one of the preceding claims. Car with an input device (10) after Claim 6 , Car after Claim 7 wherein the input device (10) is designed for operating a navigation device and / or an infotainment system and / or a mobile radio system of the motor vehicle.

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