Method for controlling a display element by a games console

Abstract

A method for controlling a position of a display element, comprising the steps: —measuring a position of a control lever, —projecting the position of the lever into a base plane, in order to determine a first set of coordinates, —determining a circle of positions, —determining a square circumscribing the circle of positions, —projecting, onto the circumscribed square, at least one coordinate of the first set of coordinates, —calculating a second set of coordinates in a Cartesian frame of reference, on the basis of the projection of the at least one coordinate of the first set of coordinates onto the circumscribed square.

Claims

1. A control method of a position and/or travel of a display element generated on a display screen by a video games console coupled to a games controller comprising a control lever arranged to be shifted by a user according to at least two degrees of freedom in a predetermined zone defined by a mechanical stop, the process comprising the steps of: measuring a position of the control lever in the predetermined zone with at least one sensor outputting at least one electric signal per degree of freedom; projecting in a base plane the position of the control lever measured with said at least one sensor, to determine a first set of coordinates U; determining a circle of positions (Cp), centered on a rest position of the control lever and passing through the projected position of the control lever in the base plane; determining a circumscribed square (Ccp) on the circle of positions (Cp; projecting onto the circumscribed square (Ccp) at least one coordinate of the first set of coordinates; calculating a second set of coordinates in a Cartesian frame of reference, on the basis of the projection of said at least one coordinate of the first set of coordinates on the circumscribed square (Ccp) so as to be able to send to the console the second set of Cartesian coordinates which is an image of the first set of coordinates; and sending the second set of Cartesian coordinates to the games console, wherein the steps as far as the calculation step of the second set of coordinates are conducted with a first resolution, and wherein a step of reducing the resolution prior to the step for sending the second set of coordinates is provided, for sending the second set of coordinates according to a second resolution, less than the first resolution.

2. The control method according to claim 1, wherein the projection step of said at least one coordinate of the first set of coordinates on the circumscribed square (Ccp) comprises a step of determining a projected position point as being a point of intersection of an axis bearing a radius of the circle of positions (Cp), passing through the projected position, with the circumscribed square (Ccp).

3. The control method according to claim 2, wherein the calculation step of the second set of Cartesian coordinates comprises: a step of calculating a first length as being a length of a segment connecting the center of the circle of positions (Cp) to the projected position, a step of calculating a second length as being a length of a segment connecting the center of the circle of positions (Cp) to the projected position point, a step of multiplying each coordinate of the first set of coordinate by a factor defined by a ratio of the second length on the first length.

4. The control method according to claim 1, wherein the projection step of said at least one coordinate of the first set of coordinates on the circumscribed square (Ccp) comprises a step of projecting onto the circumscribed square (Ccp) the projected position, according to a direction of projection defined by a radius of the circle of positions (Cp), passing through the projected position.

5. The control method according to claim 1, wherein the steps of determining the circle of positions (Cp), determining the circumscribed square (Ccp) on the circle of positions (Cp), projecting onto the circumscribed square (Ccp) said at least one coordinate, and calculating the second set of coordinates in a Cartesian frame of reference are conducted previously for all the possible projected positions of the control lever in the base plane so as to define a predefined conversion table of the first set of coordinates to the second set of coordinates.

6. The control method according to claim 5, wherein said predefined conversion table inputs the first set of coordinates, and outputs a coefficient for multiplying with each coordinate of the first set of coordinates, to calculate the second set of coordinates.

7. The control method according to claim 5, wherein said predefined conversion table inputs the first set of coordinates, and outputs the second set of coordinates.

8. The control method according to claim 1, wherein the position and/or the travel of the display element generated on the display screen is modified on the basis of the second set of Cartesian coordinates.

9. A control method of a position and/or travel of a display element generated on a display screen by a video games console coupled to a games controller comprising a control lever arranged to be shifted by a user according to at least two degrees of freedom in a predetermined zone defined by a mechanical stop, the process comprising the steps of: measuring a position of the control lever in the predetermined zone with at least one sensor outputting at least one electric signal per degree of freedom; projecting in a base plane the position of the control lever measured with said at least one sensor, to determine a first set of coordinates U; determining a circle of positions (Cp), centered on a rest position of the control lever and passing through the projected position of the control lever in the base plane; determining a circumscribed square (Ccp) on the circle of positions (Cp; projecting onto the circumscribed square (Ccp) at least one coordinate of the first set of coordinates; calculating a second set of coordinates in a Cartesian frame of reference, on the basis of the projection of said at least one coordinate of the first set of coordinates on the circumscribed square (Ccp) so as to be able to send to the console the second set of Cartesian coordinates which is an image of the first set of coordinates; and, wherein the projection step of said at least one coordinate of the first set of coordinates on the circumscribed square (Ccp) comprises at least one step of projecting on the circumscribed square (Ccp) the projected position, according to a direction of projection defined by an axis of an orthonormal coordinate system.

10. A control method of a position and/or travel of a display element generated on a display screen by a video games console coupled to a games controller comprising a control lever arranged to be shifted by a user according to at least two degrees of freedom in a predetermined zone defined by a mechanical stop, the process comprising the steps of: measuring a position of the control lever in the predetermined zone with at least one sensor outputting at least one electric signal per degree of freedom; projecting in a base plane the position of the control lever measured with said at least one sensor, to determine a first set of coordinates U; determining a circle of positions (Cp), centered on a rest position of the control lever and passing through the projected position of the control lever in the base plane; determining a circumscribed square (Ccp) on the circle of positions (Cp; projecting onto the circumscribed square (Ccp) at least one coordinate of the first set of coordinates; calculating a second set of coordinates in a Cartesian frame of reference, on the basis of the projection of said at least one coordinate of the first set of coordinates on the circumscribed square (Ccp) so as to be able to send to the console the second set of Cartesian coordinates which is an image of the first set of coordinates; and, wherein the projection step of said at least one coordinate of the first set of coordinates on the circumscribed square (Ccp) comprises: a single step of projecting onto the circumscribed square (Ccp) the projected position, according to a first direction of projection defined by an axis of an orthonormal coordinate system defining the shortest distance between the projected position and the circumscribed square (Ccp), to define a single projection point.

11. The control method according to claim 10, wherein the second set of Cartesian coordinates is defined by the Cartesian coordinates of the single projection point.

12. A control method of a position and/or travel of a display element generated on a display screen by a video games console coupled to a games controller comprising a control lever arranged to be shifted by a user according to at least two degrees of freedom in a predetermined zone defined by a mechanical stop, the process comprising the steps of: measuring a position of the control lever in the predetermined zone with at least one sensor outputting at least one electric signal per degree of freedom; projecting in a base plane the position of the control lever measured with said at least one sensor, to determine a first set of coordinates; determining an angular sector comprising the projected position of the control lever, from a plurality of angular sectors predefined of the base plane, each angular sector comprising at least one reference point through which passes a circle of reference centered on a rest position of the control lever; determining a circumscribed reference square on the circle of reference; determining at least one multiplying factor defined as a function of the determined angular sector on the basis of a projection of the reference point on the circumscribed reference square; calculating a second set of coordinates by multiplying each coordinate of the first set of coordinates with said at least one multiplying factor, so as to be able to send to the console the second set of Cartesian coordinates which is an image of the first set of coordinates; and sending the second set of Cartesian coordinates to the games console, wherein the steps as far as the calculation step of the second set of coordinates are conducted with a first resolution, and wherein a step of reducing the resolution prior to the step for sending the second set of coordinates is provided, for sending the second set of coordinates according to a second resolution, less than the first resolution.

13. The control method according to claim 12, wherein each angular sector of the plurality of predefined angular sectors is defined by the intersection of two straight lines passing through the rest position with two circles centered on the rest position, so as to cut out and cover the entire surface of the possible projections of the position of the control lever in the base plane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates a sectional view of a control lever of a games controller video for controlling a position and/or travel of a display element generated on a display screen by a video games console coupled to the games controller, by the process according to an embodiment of the invention;

(2) FIG. 2 illustrates a first execution of the processing of the measured position of the control lever of FIG. 1 performed by the process according to the invention;

(3) FIG. 3 illustrates a second execution of the processing of the measured position of the control lever of FIG. 1 performed by the process according to an embodiment of the invention;

(4) FIGS. 4a and 4b illustrate a third execution of the processing of the measured position of the control lever of FIG. 1 performed by the process according to an embodiment of the invention;

(5) FIG. 5 illustrates the case of a control lever which can be shifted in a zone limited by a mechanical stop of hexagonal shape.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIG. 1 illustrates a control lever 10 of a games controller. Such a control lever 10 can be also called “joystick” or “stick”. Typically, such a control lever 10 is arranged on an upper surface of a games controller so that it can be actuated and shifted by a user of a video games console, for example to cause movement of a figure, travel of a targeting sight, or even movement of a virtual camera of a video game.

(7) In general, the control lever 10 is therefore mobile relative to a casing 20 of the games controller video, and can be articulated relative to the casing 20 according to a ball-and-socket linkage as shown in FIG. 1. Other links between the control lever 10 and the casing 20 are possible, as for example a linkage allowing just a single flat movement of the control lever 10.

(8) However, the control lever 10 can be shifted in a predefined travel zone only, and limited by a circular stop 20a. In the case shown, the stop 20a is a ridge of the casing 20, forming a hole through which the control lever 10 passes via the casing 20. The following description is therefore linked to a circular shape of the mechanical stop, and other stop shapes are possible and will be mentioned after the description of this particular embodiment. To detect the movements of the control lever 10, the latter is connected to at least one position sensor 12, such as a potentiometer. Such a position sensor 12 detects the movements of the control lever 10, and therefore calculates a position of a point PL of the control lever 10, for example.

(9) In the present case, the control lever 10 can be shifted here according to two degrees of freedom, so that two position sensors can of course be provided, or a single position sensor with two measuring tracks to measure precisely all the positions which the control lever 10 can occupy.

(10) The stop 20a is a circle (of course, as mentioned hereinabove, other stop geometries are possible: polygon, octagon hexagon, ellipse), and if the positions of the point PL are projected into a base plane, perpendicular to the control lever when the latter is in the rest position (as shown in FIG. 1 in solid lines), the projected positions are all contained in a stop circle Cm shown in FIG. 2 or 3. The base plane can be inclined by a few degrees from a plane perpendicular to the control lever when the latter is in the rest position, and the projection of the mechanical stop circular will be an ellipse in this inclined plan.

(11) In fact, FIGS. 2 and 3 show the stop circle Cm, which is the limit of travel of the control lever 10. In conventional terms, it is understood that when the control lever 10 is stopped, the games controller must send information to the games console stating that the intensity of the travel is maximal when the control lever 10 is stopped.

(12) However, the movement of the control lever 10 is limited by a circle, but the games console must receive a position from the control lever 10 in the form of a set of Cartesian coordinates, and the norm of a vector between the origin of the Cartesian frame of reference and the projected position in the base plane must be maximal.

(13) In the Cartesian frame of reference (x-x′; y-y′) shown in FIGS. 2 and 3, when the control lever 10 is stopped pointing up, according to a 45° diagonal, the signal sent to the console must be full-scale, therefore the Cartesian coordinates are for example (1, 1). However, if an inscribed square Cim is traced in the circle Cm, and if the control lever 10 is shifted upwards out of the inscribed square Cim, and still in the circle Cm without be stopped, the coordinate according to the axis y′-y would have to be further increased, but this would distort the interpretation made by the console since the norm of the vector between the origin and the projected position in the base plane would be greater than that of the vector when the control lever 10 is stopped on the diagonal.

(14) As a consequence, there would be incoherence of the intensity of the travel restored by the console: intensity 1 when the projected position of the control lever is on the diagonal at 45° and on the circle Cm (control lever 10 stopped at 45°), and greater intensity when the projected position of the control lever is outside of the inscribed square Cim, but not on the circle Cm (control lever 10 not stopped).

(15) To avoid this incoherence, once the projected position of the control lever 10 exits the inscribed square Cim, one of the Cartesian coordinates is imposed on 1, which amounts to ignoring four travel zones which are quarter discs defined by the zones of the stop circle Cm which are out of the inscribed square Cim.

(16) It is understood that during travel of the control lever 10 according to a cardinal direction (the projected position is therefore on one of the axes yy′ or xx′), full scale is reached once projected position is on or exceeds the inscribed square Cim.

(17) To rectify this disadvantage, and to consider the entire travel zone of the stop circle Cm, the invention proposes calculating the set of coordinates which will be sent to the games console by creating homothety from the projected position of the control lever in the base plane.

(18) FIG. 2 shows a first execution of this calculation, in two specific cases.

(19) In the first specific case, the control lever is in the position A, and the projected position in the plan basis has as coordinates (a1, a2). Initially, a circle of positions Cp is determined, which passes through the projected position of coordinates (a1, a2), and which is centered on the rest position of the control lever (the origin of the reference frame (xx′, yy′)).

(20) Next, the process determines a circumscribed square Ccp on the positions circle Cp, and determines the point of intersection of the radius passing through the projected position of coordinates (a1, a2) with the circumscribed square Ccp, which has as coordinates (a′1, a′2).

(21) It is the coordinates (a′1, a′2) which will be sent to the games console. To calculate them, the length of the radius R1 of the circle of positions which passes through the point (a1, a2) is determined by way of the Pythagoras theorem (equation 1). And then the length R2 of the segment which has as its ends the origin of the frame of reference and the point of coordinates (a′1, a′2) is determined by the Thales' theorem (equation 2).
R1=√(a1.sup.2+a2.sup.2)  Equation 1
R2=(a1.sup.2+a2.sup.2)/a2  Equation 2

(22) It then remains to multiply each coordinate of the first set of coordinates (a1, a2) by the ratio R2/R1 to find the coordinates of the second set of coordinates (a′1, a′2).

(23) The process therefore performs homothety based on a difference in dimension between the circle of positions Cp and its circumscribed square Ccp. The projected position is artificially “augmented” or “displaced” towards the circumscribed square Ccp to find the second set of coordinates. This is about projection according to the radial direction.

(24) It should be noted that the second set of coordinates is equal to the first set of coordinates when the control lever is shifted only in a cardinal direction (along the axis xx′ or yy′): the homothety then has a ratio of 1. Also, the homothety ratio is maximal when the control lever 10 is shifted along a diagonal: the ration is then around 1.414, that is, square root of 2.

(25) As a consequence, the console does receive a second set of Cartesian coordinates, with full scale only when the control lever is stopped, and this without ignoring the measuring zone.

(26) The position B of FIG. 2 correctly shows the control lever 10 stopped, and the coordinates of the projected position are (b1, b2), located on the stop circle Cm. The transformation amounts to calculating the projection of the projected position on the circumscribed square Ccm according to the radial direction which passes through the projected position to calculate the second set of coordinates (b′1, b′2) which will be sent to the console.

(27) The process according to embodiments of the invention can perform the steps for determination of the circle of positions Cp, of the circumscribed square Ccp and projection to each measurement of the position of the control lever 10 to calculate the second set of coordinates with the homothety ratio, or else a predefined table can be built by calculating the homothety ratio for all possible positions, storing this predefined table in the games controller and simply searching for the adequate ratio as a function of a measured position, and multiplying the coordinates measured by the adequate ratio to find the second set of coordinates. As an alternative the second set of coordinates can be stored directly in the predefined table.

(28) FIG. 3 shows a first alternative. In this alternative, determination of the circle of positions Cp and of the circumscribed square Ccp is identical. However, instead pf projecting the projected position according to the radial direction, the process performs a single projection parallel to one of the axes xx′ or yy′, and in particular towards the side of the circumscribed square which is the closest, to find the second set of Cartesian coordinates to be sent to the games console.

(29) In particular, in the specific case where the control lever 10 is in the position A, the first set of coordinates of the projected position is (a1, a2). The closest side of the circumscribed square Ccp is the upper horizontal side, so that the coordinates of the second set of coordinates will be (a′1, a′2), with:
a′1=a1
a′2=√(a1.sup.2+a2.sup.2)

(30) In the event where the control lever 10 is in the position B (stopped), the first set of coordinates of the projected position (onto the circle Cm therefore) is (b1, b2), and the closest side of the circumscribed square Ccm is the vertical right side, therefore the projection of the projected position on the circumscribed square Ccm will have (b′1, b′2) as second set of coordinates with:
b′1=√(b1.sup.2+b2.sup.2)
b′2=b2

(31) FIGS. 4a and 4b show a third possible execution to determine the second set of Cartesian coordinates to be sent to the games console.

(32) In this execution, the stop circle Cm and its circumscribed square are not shown, so as not to clutter the figures. In fact, the entire surface of the stop circle Cm is cut into angular sectors Si. A single one of these is seen in FIG. 4a, and it is this one which comprises the projected position of the control lever 10 in position A. The angular sector in question Si is a portion of a crown delimited laterally (or angularly) by two straight lines which pass through the center of the frame of reference (the rest position of the control lever 10). The entire surface of the stop circle Cm is cut by angular sectors, making it possible to identify for each projected position of the control lever a particular angular sector which contains it.

(33) For each angular sector it is possible to define a reference point contained in this angular sector, a circle of positions Cp which passes through this reference point and a circumscribed square Ccp to this circle of reference. It is possible to determine the projection of the reference point on the circumscribed square Ccp, according to the radial direction, and determine a multiplying factor as being the ratio of the lengths of the segment connecting the projection of the reference point (on the circumscribed square Ccp) to the origin, and of the radius of the circle of positions. This for each angular sector Si.

(34) As a consequence, for each point forming an element of a particular angular sector Si, it is possible to multiply its coordinates of the first set of coordinates by the multiplying factor particular to this sector, to calculate the second set of coordinates. As FIG. 4b shows, all the points of the angular sector Si are projected with the same multiplying factor towards an angular sector S′i, substantially square.

(35) In other terms, the process carries out processing in batches or by angular sectors to limit the calculations to be performed, by means of a table of multiplying factors which is stored in the games controller, and which gives the value of the multiplying factor to be used as a function of the angular sector Si which contains the projected position.

(36) Of course, if there are two dimensions the multiplying factor comprises two values, one for each dimension.

(37) It will be understood that various modifications and/or improvements obvious to the skilled person can be made to the different embodiments of the invention described in the present description without departing from the scope of the invention defined by the appended claims. In particular, reference is made to a first set of coordinates, and it is not specified which format is used for this first set of coordinates. The invention can function with a first set of cylindrical, spherical, or even Cartesian coordinates.

(38) As mentioned hereinabove, the case of a mechanical stop of circular shape has been processed in detail, but the case of a mechanical stop of hexagonal shape can be possible for example, as shown in FIG. 5. The method is identical, with projection of the position of the lever onto a base plane, then determination of a circle of positions which passes through the projected position of the control lever, then projection of the projected position onto a circumscribed square to the circle of positions.

(39) However, when the control lever is in mechanical stop on the casing it can go no further than the hexagonal shape shown in FIG. 5. In the event where the control lever is shifted on the axis xx′ only, it is stopped quickly with the casing, and a first circle of positions Cm1 can be determined, as well as a first circumscribed square Ccm1. In the event where the control lever is shifted on the axis yy′ only, it can be shifted further before being stopped with the casing (in the region of an apex of the hexagon), and a second circle of positions Cm2 can be determined, and a second circumscribed square Ccm2.

(40) As the second circumscribed square Ccm2 has a size greater than the first circumscribed square Ccm1, there is distortion in the set of second coordinates obtained, which naturally has a greater norm when the lever is stopped mechanically in the region of an apex (second circumscribed square Ccm2) rather than in the middle of a side (first circumscribed square Ccm1). However, this distortion is introduced by the form of the mechanical stop, and not by the method of the present invention.

(41) It can also be seen that the control lever cannot go as far as the apices of the polygonal shape of the mechanical stop (as the control lever has a diameter which will be stopped on the two sides forming the apex by intersection), which amounts only to “rounding” the apices of the hexagon shown to obtain the possible positions of the stopped control lever. The method with projection onto the base plane, determination of the circle of positions, of the circumscribed square and projections stays the same.