WO2006072703A2

WO2006072703A2 - Workstation for assisting in the learning of manuscript writing and method for assisting in corresponding learning

Info

Publication number: WO2006072703A2
Application number: PCT/FR2005/003286
Authority: WO
Inventors: Bernard Hennion; Philippe Gouagout
Original assignee: France Telecom
Priority date: 2005-01-03
Filing date: 2005-12-27
Publication date: 2006-07-13
Also published as: WO2006072703A3

Abstract

This workstation for assisting in the learning of manuscript writing comprises: a force feedback element having a stylus (14) that is capable of being manipulated by a user for writing on a writing surface (30); a force generator (18) that controls the force feedback element for causing the application of motive forces upon the force feedback element, and; a central control unit (20) of the force generator comprising software means for controlling and executing learning sequences. The force feedback element comprising the stylus (14) as well as the screen are integrated in the workstation support.

Description

ASSISTANT AID STATION FOR WRITTEN TEACHING MANUS CRITERIA AND APPRENTICESHIP ASSISTANCE SYSTEM C O RRE P ON D ON

The invention relates to the learning of handwriting and relates, more particularly, to a position and a method of assisting with the learning of handwriting, especially for children. Such a post and such a method are particularly intended to provide assistance to the learning of handwriting for people with writing difficulties or people with visual impairment, students in primary classes.

With existing learning systems, students write too fast, causing writing errors, and / or, in addition, in a jerky manner.

The document US 5397865 proposes to overcome these deficiencies by proposing a progressive display. This measure, however, is likely to accentuate the writing in a jerky way. The present invention aims to overcome the aforementioned drawbacks of devices of the prior art. This goal is achieved by taking into account the dynamic information of writing as a haptic parameter. A particularly interesting application of the invention relates to the learning of handwriting for children of preparatory courses presenting difficulties of writing. It should be noted, however, that it concerns both writing and reeducation. Such assistance is to guide the hand of the child, or even an adult, along a predetermined path that corresponds to a cursive and this, repeatedly.

This assistance also consists in allowing a control of the acquired knowledge. The assistance also consists of proposing various learning sequences that can make learning to write effective and fun.

Also, the aim of the invention is to enable, on the one hand, the acquisition of knowledge relating to the form of the cursives and, on the other hand, a control of knowledge as well as acquired.

Another object of the invention is to allow the unfolding of various learning sequences consisting of the execution of predetermined exercises. The object of the invention is therefore, according to a first aspect, a handwriting learning aid station comprising a force feedback member comprising a stylus which is adapted to be manipulated by a user to write on a writing surface, a force generator which controls the force feedback member to cause the application of motor forces, from the dynamic information of the writing, on the force feedback member and a central control unit of the force generator comprising software means for controlling the execution of training sequences.

According to another characteristic of the method which is the subject of the invention, the speed of displacement in reading as a function of the radius of curvature of the letters of the fault displayed.

According to another characteristic of the method which is the subject of the invention, the mode of learning of writing is a guided mode according to another characteristic of the method which is the subject of the invention, the mode of learning of writing is an assisted mode. .

According to another characteristic of the invention, the control software means comprise means for calculating the forces applied to the force feedback member.

In one embodiment, this station is provided with storage means for storing information describing the writing formed by the user.

According to an additional characteristic, the station also comprises a keyboard provided with preprogrammed keys adapted to respectively cause the execution of the training sequences. According to another aspect, the object of the invention is a method for assisting the learning of handwriting comprising the following steps in which a user moves a force-return member carrying a stylus on a surface of writing and simultaneously a force generator controlled by a central control unit applies forces on the force feedback member to provide a haptic perception to the user during writing.

In one embodiment of this method, this method comprises several operating sequences each corresponding to a learning mode, comprising at least one mode chosen from an unassisted write mode, during which writing descriptive information is recorded, a fully automatic readback mode during which the force feedback member is moved fully automatically, assisted writing modes, a drawing mode and a letter configuration mode in which the user alters the shape of a written letter.

In particular, during the assisted writing modes, it causes the display on a screen of a letter or a set of letters in the form of a model, the user then having the task of copying the letter as well as displayed.

In a particular learning mode, during replay, efforts are applied to the force feedback member to urge it along the model.

These efforts can be variable.

In addition, according to another learning mode, the difference between the track made by the user and the model is monitored, the difference is compared with a maximum permissible threshold value and the number of overtakings is counted. of said threshold value.

In yet another mode of learning, the forces applied to the force feedback member are controlled so as to simulate the writing on a sheet of paper.

It is also possible to calculate the thickness of a line drawn by means of the force feedback member according to a force applied by said member on a writing surface.

Other objects, features and advantages of the invention will appear on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings in which: FIG. 1 is a perspective view of a handwriting training aid station according to the invention; Figure 2 is a perspective view of the support of the station of Figure 1; FIG. 3 is a schematic view from above of the support of FIG. 2; FIG. 4 is a block diagram of the help station for learning from Figure 1; FIG. 5 is a view of the screen of the station of FIG. 1 illustrating a first mode of use of this station; FIG. 6 shows another view of the screen of the station of FIG. 1 illustrating another mode of use of this station; Figure 7 shows yet another view of the screen of the station of Figure 1 showing the font stored in the memory means; Figure 8 is a view of the screen of the station of Figure 1 illustrating a particular mode of use of the station according to the invention; Figure 9 shows yet another view of the screen of the station of Figure 1 illustrating another mode of learning handwriting; FIG. 10 is a view of the screen of the station according to the invention illustrating yet another mode of learning handwriting; and Figure 11 illustrates yet another mode of use of the station according to the invention.

FIG. 1 shows a perspective view of a handwriting training aid according to the invention, designated by the general reference numeral 10.

In the exemplary embodiment shown, this station 1 0 is intended to provide assistance to learning or re-education of writing with young children. It will be noted, however, that the invention may also be applied, if necessary, universally to provide assistance during rehabilitation or when learning to write.

It should be noted, however, that the invention applies more particularly to sighted children but presenting difficulties of writing or to children with amblyopes.

The station 10 essentially comprises a support 12; a stylet 14 to be manipulated by the user and carried by a force feedback member 1 6; a force generator 1 8 for controlling the force return member 1 6; and a central management unit 20 provided with a human-machine interface 22 constituted by a keyboard whose keys are programmed to start the execution of respective learning phases. The force return member constitutes a haptic arm intended to apply driving forces to the stylet 14 to guide it along a predetermined path, in this case a cursive or generally a geometric shape, or to apply resistant efforts on the stylus to solicit against such traj and, when manipulated by the user, to provide assistance with writing, or to provide other types of sensations to the user, for example in applying efforts simulating the grain of a sheet of paper.

The support 12 constitutes, for its part, a table to which the user comes to take a seat.

Referring also to Figures 2 and 3, the table is for this purpose provided with a cut or notch 24 of a width and depth calculated for the abdomen of a child of about six years.

This cutout 24 is delimited laterally by two extensions 26 and 28 which constitute armrests, that is to say, surfaces on which the arms of the user can come to bear. The support 12 also delimits a writing surface

30.

The writing surface 30 may be any type of surface on which a child can write. However, according to a feature of the invention, this surface is a human-machine interface that allows the writing but also to present information to the user.

Thus, the writing surface 30 is constituted by a haptic plane above a flat screen, to point directly with the stylus. Such screens are widespread and therefore will not be described in detail later.

In order to allow the housing of the screen in the support 12, it is provided with two plates, namely an upper plate 32 and a lower plate 34 separated by spacers, such as 36, evenly distributed around the periphery 12. These trays 32 and 34 delimit between them a housing 38 in which is inserted the screen 40. A cut in the upper plate 32 makes accessible the screen 40. The space between the upper trays 32 and lower 34 further allows the passage of all the cables necessary for the operation of the workstation, particularly the cables necessary for the operation of the screen 40.

Note that, preferably, the writing surface 30 has the dimensions, or even the appearance of a page of a school notebook. In addition, so that it is easy to use, the screen 40 is positioned between the upper and lower trays so that it is flush with the upper surface of the upper tray. Alternatively, it may also be provided to cover it with a light-transparent protection plate which is inserted into the cutout made in the upper plate 32 so that it is flush with the upper surface of this plate.

Regarding the stylet 14, it has the shape of a conventional stylus. It is carried by a haptic arm 16. Such an arm is controlled by the force generator 18 under the control of the processing unit 20 so as to eliminate degrees of freedom of positioning and thus force the child to write according to a traj and predetermined correspond to a cursive. Such an arm constitutes a conventional body within the reach of a person skilled in the art. It will not be described in detail later. It should be noted, however, that haptic arms such as those marketed by the Company "SENSABLE®" or "IMMERSION®" may be suitable for such applications.

Referring to FIG. 2, in order to obtain precise positioning of the haptic arm 16 with respect to the surface 30, the upper surface of the support 12 is provided with a housing 42 in which the base 44 of the arm 16 is positioned. Thus, the arm can be positioned so that the stylet 14 is generally centered with respect to the writing surface 30.

It will also be noted that the cut-out or indentation 24, as well as the extensions 26 and 28 are conformal so as to correctly position the child and that his arm can naturally grasp the stylet 14. Thus, as can be seen in FIG. the bottom of the notch 24 has for example a width L l equal to 210 mm, the opening of the notch has a width L2 equal to 350 mm and the width L3 of the support 12 at the extensions 26 and 28 is approximately equal to 700 mm. The depth P of the support 12 is, for its part, equal to 850 mm. As previously stated, these dimensions are optimized for a child of preparatory class. As can also be seen in FIG. 3, preferably, the writing surface 30 as well as the housing 42 for the haptic arm 16 are offset with respect to the general axis XX 'of the support 12 as a function of the lateralization of the child. Thus, for example, as shown in FIG. 3, for a right-handed person, the writing surface 30 and the arm 16 are shifted to the right.

On the contrary, for a left-handed child, the impression 42 as well as the writing surface 30 will be shifted to the left.

Alternatively, it is also possible to provide a workstation right / left, sliding to the right or left of the screen (40) and the haptic arm (16) in their housing enlarges for the case.

The haptic arm and the screen are deported 10 cm to the right for right-handed and vice versa for lefties, compared to the notch inside which is placed the body of the child. The workstation and the screen are then on the side of the child's right arm or left arm.

Due to the offset of the writing surface 30 and the haptic arm

16 with respect to the axis XX 'of the station, the surface thus released can for example, allow to receive the human-machine interface 22. This interface is preferably constituted by a keyboard for an educator or a teacher to launch to the screen an exercise to perform.

Note that the support 12 generally adopts the shape of an ellipse to obtain a minimum size facilitating its transport and its positioning on a conventional table.

However, the presence of the imprint 42 opposite the extensions 26 and 28 allows, after assembly of the haptic arm 16, an offset of the center of gravity of the station and therefore allows a positioning of the station cantilevered on a table, that is to say in a position in which the extensions 26 and 28 extend beyond the plane of the table and thus allow to slide under the armrests a chair for example adjustable in height.

For a positioning of the stylus 14 with respect to the writing surface 30, a space of 2 cm is provided between the reception cavity 42 of the haptic arm and the writing surface. Using a conventional haptic arm, this distance allows to advance 12 cm the stylus 14 above the screen. The stylus is naturally placed in the hand of a child of preparatory class, whose forearm size is on average 20 cm.

Furthermore, the central unit 20 is provided with all the hardware and software means for controlling the force generator 18. In particular, this unit 20 is duly programmed to start different learning phases constituting different exercises to be performed by the user.

It can be seen in FIG. 4 that the central unit 20 is provided with a first memory zone Z 1 into which various programs are loaded, making it possible to drive the force feedback unit via the generator For example, the learning may consist of guiding the hand of the hesitant user along a targeted cursive line, first with high force constraints to fully guide him, up to the total release of the organ 14, while passing through all the intermediate values of degressive coercion. As will be described in detail later, it is also possible to start the execution of learning phases in which one or more letters are presented on the screen, the user then taking care to copy them, or guided way, either in an unguided way. The central unit 20 also proposes a learning program in which letters written by the user are stored in another memory zone Z2 for later analysis.

Finally, it can be seen in FIG. 4 that the central unit 20 is provided with calculation means C making it possible to calculate the forces to be applied to the stylet 14, as will be detailed hereinafter.

Thus, for example, the station 10 offers seven learning modes, although other complementary learning modes can also be provided. With reference to FIG. 5, according to a first learning mode, no force is applied by the force generator 1 8 to the stylus 14. This stylet then behaves like a conventional stylus. However, the central unit 20 stores descriptive information of the writing formed on the screen 30. This information is for example constituted by the coordinates of the points or lines drawn by the user as well as by dynamic information. The central unit 20 comprises for this purpose means of timing in the form of a clock H allowing the recording of this information in sampled form. For example, the sampling frequency is of the order of Khz. This information is stored in the third memory zone Z2. The aforesaid storage is performed for the purpose of controlling the learning. In the unassisted write mode, for example, the above-mentioned storage makes it possible, in another variant of the method, to use this writing as a model or a guide during learning, in particular in replay mode. The trace of the handwriting thus memorized makes it possible to implement subsequent processing of analysis and quantification of the acquisition of writing by the user. It is thus possible, for example, to implement a subsequent calculation of the disfluence or to implement a semi-automatic BHK test,. It should be remembered that the disfluence in writing is the variability of the pen speed, the number of extrema of the pen velocity module along the manuscript trace. A child who begins to learn to write often interrupts to look at the model of the letter, causing many accelerations and braking of his pen. The disfluence is high. A child who, on the contrary, acquired writing at the end of the elementary course has automated the neuromotor movements of his phalanges, which have become unconscious. We then talk about the progress of a gestural map because his pen does not accelerate and brakes only once by raising or lowering the track. Visual feedback is suppressed and the disfluence is minimal. It is further recalled that the BHK test is a quantization test of the acquisition of the handwriting aptitude from 1 3 calibration criteria of the traces.

Referring now to FIG. 6, according to a second learning mode, the central unit 20 implements a trailing replay learning program according to which the user sees the stylus moving according to a prerecorded writing or a letter cast iron stored in a third memory zone Z3. Thus, according to this second learning mode, the stylus is fully guided, the replay is then fully automatically.

As can be seen in FIG. 7, it is also possible, according to a third learning mode, to consult the memorized font in the storage area Z3. This static and dynamic font is defined by control points consisting of horizontal tangent points, vertical tangent points, inflection points, cusp points, and cursive start points. and cursive endpoints. It is defined by three parameters, namely Cartesian coordinates X ₅ Y and by an angle of the tangent with an axis OX. Each arc is elliptical or in a straight line. The motion kinematics on the cast follows the following psychophysical law: speed._reading = kx Radius _Burge ^{2 3}

According to a fourth learning mode, the central unit 20 causes the display 30 to display one or more letters (FIG. 8). As can be seen in FIG. 8, the letters are each formed by a double line L 1 and L 2 delimiting a traj and to be followed by the user. This traj and therefore constitutes a margin of errors not to be exceeded. The central unit 20 then monitors the track made by the user and compares it with a maximum allowable threshold value corresponding to the boundaries L 1 and L 2 of the track and counts down the number of exceedances of this threshold value. This mode of learning thus constitutes a particularly playful mode of learning. The count can be viewed by means of an I icon displayed on the screen 30.

Referring now to Figure 9, according to a fifth embodiment, the CPU 20 causes the display of a letter L on the screen 30. This letter is a template to be copied by the user.

Note that in the embodiment described with reference to Figures 8 and 9, it is possible to provide a drawing assistance by driving the stylus 14 by means of the force generator so as to solicit the stylus along a path ideal and with an effort of attraction adjustable according to the level of difficulty to obtain.

According to a sixth embodiment, described with reference to FIG. 10, a letter is displayed on the screen 30. The user can then modify its shape by selecting a control point and move it to another location of the screen. 'screen. The calculator then immediately recalculates a new elliptical arc so that a new form of carved letter appears in real time on the screen 30. Finally, with reference to FIG. 11, station 10 offers a free drawing mode to allow the user to draw directly on the screen. In this respect, various colors can be used, as well as an eraser. This learning mode is particularly adapted for the user to become familiar with the various functions proposed by the station 10.

As indicated above, during the different learning modes concerned, the computer C controls the force generator 1 8 so that predetermined forces are applied to the stylet 14. In particular, for the different learning modes, the efforts applied to the stylet 14 are calculated to simulate the resistive force of a stylus pressed against a sheet of paper so as to simulate the grain of a sheet. Similarly, the forces applied manually on the stylus 14 are measured and are delivered to the computer C so as to adapt, accordingly, the thickness of a line drawn on the screen. It is also possible, depending on the speed of the stylus 14 and the force applied manually on the screen, to generate sounds that correspond to the sounds generated by a real stylus on a sheet of paper. In all writing modes, a virtual model of a sheet of paper, which constitutes a horizontal haptic plane, is created.

The texture simulating the grain of the paper and allowing to highlight the friction of the feather is governed by the following relation:

Force_XY = friction x speed_ feather + grain x sine (Freq X x X + Freq Y x Y + phi) In which:

Force_XY represents the force applied to the stylus 14 by the force generator 1 8 to simulate the grain of the paper; friction represents the friction exerted by the stylet 14 on the screen 30; speed_feather represents the speed of pen 14; grain is a variable parameter representing a grain of a sheet of paper;

Freq X and Freq Y denote the spatial frequencies of the grain: a high frequency corresponds to a fine grain, and a low frequency to a coarser grain; and phi denotes a random phase. Similarly, the texture of the paper is simulated by means of a sound signal developed according to the speed of movement of the stylus and a type of stylus tip whose operation should be simulated. The CPU 20 also manages the full and the untied using a model of deformation of a stylus pen under the effect of the pressure exerted by the user on the virtual sheet thus simulated. To this end, you should change the width of a line (Stroke_width) according to a pen hardness (pen hardness), the type of pen used (pen Z), and the type of sheet (sheet Z) to from the following relation:

Width Jtrait = - hardness _plume x (pen Z - sheet Z) According to the second mode of learning, according to which the stylus is completely drawn, one creates first of all virtually a smart pen which moves along the ideal plot with a ideal speed. The stylus of the user (feather_child) is then towed according to a force ("Force") towards this smart pen (feather_intelligent) which connects the plot according to the equation:

Force = for this _attr action x (feather _child-intelligent_feather) where force_attraction is the effort applied to the stylus 14 by the user.

As you can imagine, this smart pen re-reads a pre-recorded recording done by a show of hands by a teacher or goes through a predefined font. The font memorized in the third memory zone Z3 consists of the twenty-six letters of the alphabet and further comprises ten accented letters. Each letter consists of a set of control points defined by three coordinates in space and an angle of the tangent to the cursive line at that point. These points are line starts, line ends, vertical and horizontal tangent points, inflection points and cusp points. They are interconnected by elliptic arcs or straight segments. They are traversed by the smart pen at the psychophysical speed (speed_reading) according to the equation: speed_reading = kx Radius _Curbure ² in which: Radius_Curd refers to the radius of curvature of the trace handwritten to the point where the pen touches and k is the inverse of the square root of the product of the 2 half-axes of the ellipse

For a more detailed description of the psychophysical law speed_reading course as a function of the _Curbure Ray, we can usefully refer to the article by Viviani P. "Motor skills in the perception of dynamic events, in Common mechanisms in perception and action: attention and performance" W. Prinz and B. Hommel Editors, 2002, Oxford Universty Press: Oxford P 406-442. In the fourth learning mode, the stylus 14 of the user is partially drawn towards the cursive line perpendicularly according to the equation:

Force = for this _attr action x (Child_Plug-projection_ child_plume) where: child_plume_spray is the projection of the stylus tip on the plane of the writing surface; and feather - child designates the position of the stylus in the space. However, the user remains free to browse the letter at the speed that suits him. An option allows you to prevent it from rolling back or not. Each time it moves away from more than a certain precision threshold of this cursive line, a counter is incremented. A progressive decrease of the force of attraction to the plot makes it possible to increase the difficulty and to adapt to the address acquired by the user.

In the model learning mode, the user is assisted by an ideal model to follow, arranged to his left for a right-hander and whose display mode is progressive or permanent. This model can come from either a pre - recorded teacher 's handwriting or an existing mathematical or aesthetic font (italic, full and loose).

In the sixth learning mode, the user can haptically enter any control point of the font and move it where he wishes. The computer then recalculates in real time the ellipse or ellipse arcs or segments of the line, which allows the user to realize the new look of the letter thus modified. A force of attraction (Force) between the stylus and the point of closest control can be constructed from a search of the minimum distance according to the equation:

Force = - for this _attr action _pt_control x (feather _child - close_control_control) + force _^ attraction x (Child feather - projection_feather_child) in which:

Pt_controle_proche means the nearest control point; and for this _attr action _pt_control is the pulling force towards the control point

The user then perceives a hollow at the location of the control points but is simultaneously guided along the trace of the letter.

The invention finally covers a computer program product recorded on a storage medium for execution on a computer or by the central processing unit (C) of the handwriting training station, obj and the The invention is illustrated in FIGS. 1 to 4. This computer program product is remarkable in that it includes a sequence of instructions which, when executed, implement the handwriting learning method. , as described with reference to Figures 5 to 1 1 in the description.

Claims

1. Handwriting learning aid station, characterized in that it comprises a force feedback member comprising a stylet (14) which is adapted to be manipulated by a user to write on a surface of writing (30), a force generator that controls the force return member (16) to cause the application of motor forces from dynamic information of the writing on the force feedback member and a central control unit (20) of the force generator comprising software means for controlling the execution of training sequences.

2. Station according to claim 1, characterized in that the software means comprise means for calculating the forces applied to the force feedback member (14).

3. Station according to one of claims 1 and 2, characterized in that it further comprises storage means (Z2) for storing information describing the writing formed by the user.

4. Station according to any one of claims 1 to 3, characterized in that it comprises a keyboard (22) provided with preprogrammed keys adapted to respectively cause the execution of training sequences.

5. Station according to one of claims 1 to 4, characterized in that it further comprises storage means (Z3) of at least one cast iron.

6. Station according to one of claims 1 to 5, characterized in that the software means for the calculation of the dynamic information of the writing a psychophysical law.

A method of assisting with handwriting learning, characterized in that it comprises the following steps in which a user moves a force - return member carrying a stylet (14) on a surface of writing and simultaneously a force generator (18) controlled by a central control unit (20) applies, from dynamic information of the writing, efforts on the force feedback member to provide a haptic perception to the user when writing.

8. Method according to claim 7, characterized in that the speed of displacement in reading is a function of the radius of curvature of the letters of the fault displayed.

9. The method of claim 7 or 8, characterized in that the write learning mode is a guided mode.

10. The method of claim 7 or 8, characterized in that the write learning mode is in assisted mode.

11. Method according to one of claims 7 to 10, characterized in that it each comprises a learning mode, comprising a mode selected from an unassisted write mode during which descriptive information is recorded. writing, a fully automatic readback mode in which the force feedback member is moved fully automatically, assisted writing modes, a drawing mode and a letter configuration mode in which the user alters the form of a written letter.

12. Method according to one of claims 7 to 11, characterized in that it comprises the calculation of the dynamic information of the writing using a psychophysical law.

13. Computer program product recorded on a storage medium, for execution by a computer or by the central processing unit of a writing aid station, characterized in that comprises a sequence of instructions, allowing, during their execution, the implementation of the method according to one of claims 7 to 11.

14. Central management unit of a handwriting training aid station, characterized in that, in addition to a calculation unit and a control clock, said central unit comprises at least:

first means for memorizing a program making it possible to drive a force feedback member;

second means for storing information describing the writing formed by the user; third means for storing at least one fault.