WO2018055072A1

WO2018055072A1 - Converting user input to movement control based on a predefined user profile

Info

Publication number: WO2018055072A1
Application number: PCT/EP2017/073992
Authority: WO
Inventors: Søren MØRCH
Original assignee: Tks A/S
Priority date: 2016-09-23
Filing date: 2017-09-22
Publication date: 2018-03-29

Abstract

The invention relates to a method for converting a user input to a control output for controlling movement of an element, the method comprising: -receiving a user input from an input unit operated by said user and where the input unit receives the user input by detecting movement by said user, -converting said user input to a control output, based on a predefined user profile, wherein said user profile is defined based on the movement characteristics of said user operating said input unit. Thereby, increased stability of control is achieved for all the usage situations where this is useful. For example, even a user with tremulous hands may operate a device in a controllable manner as tolerances are introduced, where fine motoric skills are not needed to maintain straight and comfortable control. When e.g. steering a wheelchair, this converted control allows comfortable travel and may even allow some disabled persons to attain a wheelchair who had previously not been thus allowed because of their handicap. Further, this more stable and straight motion of the wheelchair maintains the wheels, bearings and structure of the wheelchair whose lifespan is extended. Further, children may more comfortably attain control in digital environments, such as of cursors or digital vehicles like cars, planes and ships, for example in simulations or games. This enhances the experience and may retain the child at play longer, strengthening their learning curve. Even further, some industries may benefit from the increased predictability of movement allowed by the invention, such as movement of heavy-duty machinery or robotic control.

Description

CONVERTING USER INPUT TO MOVEMENT CONTROL BASED ON A PREDEFINED USER PROFILE

FIELD OF THE INVENTION

The present invention relates to a method for converting a user input to a control output for controlling movement of an element. The invention further relates to a converter for such control and a wheelchair comprising such a converter.

DESCRIPTION OF PRIOR ART

Many situations require fine motor function to steer, such as navigation whether digital or in real life. Wheels, computer mice, joysticks and controllers are just some of the user input devices that allow users to control interaction with a device to be controlled.

This may be especially important in high stakes situations such as moving advanced robotic gear and for motorized movement by persons with poor motoric skills. Also, in development of motoric skills by children, assistance is missing that allows them to enjoy improved control of digital vehicles and devices, since in their development, they have poor fine motoric function, and failing in these games due to a too sensitive controlling may lead to them giving up, thereby losing the opportunity to develop the skills associated with such control.

One group of users in need of improved control are persons with movement disabilities. Historically, these people have been restricted from many freedoms, which are normally taken for granted, such as moving from one place to another at their own volition, power and leisure. This inability is a tremendous stressor on these people, who may feel powerless and/or like a burden to those around them.

With technological development, a portion of those who were previously unable to transport themselves have been allowed doing so, such as persons with spinal cord injuries being able to manoeuvre a wheelchair by a joystick mounted on the wheelchair, since their arms may be perfectly healthy.

Other users may retain some coarse control over their arms and hands but be unable to steer precisely because of for example tremulous hands. Such may be the case for persons with Parkinson's disease, Cerebral Palsy or persons of advanced age. These people may be unable to attain a motorized and self-controlled wheelchair since their fine motor skills are impaired and they would pose a danger to themselves and others.

Normal motorized and self-directed wheelchairs have a speed proportional to the displacement of a joystick on the wheelchair. A solution of the art for some users is to reduce the gearing of the wheelchair, whereby the speeds attained by the wheelchair is reduced throughout its spectrum. This decreases the danger posed by some users, but does not allow a wheelchair for all users, especially those with tremulous hands.

Therefore, there is a need for systems and methods of control for persons with reduced fine motoric skills, for example allowing safe and comfortable self-controlled transportation for disabled persons.

SUMMARY OF THE INVENTION

The object of the invention is to solve some of the above-mentioned problems.

In accordance with the invention, a method is provided for converting a user input to a control output for controlling movement of an element, the method comprising:

receiving a user input from an input unit operated by said user and where the input unit receives the user input by detecting movement by said user,

converting said user input to a control output, based on a predefined user profile, wherein said user profile is defined based on the movement characteristics of said user operating said input unit.

Typically, the user input would relate to an input from a control unit for operating a moveable device. The control unit may be a mouse, joystick or another control unit of the type where the actual movement of the control unit (e.g. stick on joystick, pad on joystick, movement of controller, movement detection via a camera) are to be converted to a control output controlling a moveable element and where the movement of the control unit is indicative of how the moveable element should move. The element to be moved may be a physical element such as a crane, wheelchair or robot being controlled via e.g. a joystick. Further, the element may be a virtual element such as a car, soccer player or another moveable object in a computer game. The predefined user profile converting the user input to the control output, may be based on a specific detection of the movement characteristics of the user controlling the input unit, e.g. by detecting a pattern of the users movements and extremes, which should not be directly translated to actual movement of the element being controlled. This predefined profile will then be adaptive and be generated via a learning process. As an alternative, the predefined user profile may be programmed before performing the control, where initial tests of the user intended to control the element is made and this results in data that is used for programming the predefined user profile. A further possibility is that there are a number of pre-programmed predefined user profiles e.g. based on types of user and the user type is selected as the predefined user profile before the user starts operating the moveable element. As an embodiment, the predefined user profile may be programmed via a user interface such as via a wireless app or another user interface allowing the predefined user profile to be selected.

The user profile would in an embodiment limit the user inputs detected via the user control to limited control outputs, where this limitation is determined based on the predefined user profile. Thereby, increased stability of control is achieved for all the usage situations where this is useful. For example, even a user with tremulous hands may operate a device in a controllable manner as tolerances are introduced, where fine motoric skills are not needed to maintain straight and comfortable control. When e.g. steering a wheelchair, this converted control allows comfortable travel and may even allow some disabled persons to attain a wheelchair who had previously not been thus allowed because of their handicap. Further, this more stable and straight motion of the wheelchair maintains the wheels, bearings and structure of the wheelchair whose lifespan is extended.

Further, children may more comfortably attain control in digital environments, such as of cursors or digital vehicles like cars, planes and ships, for example in simulations or games. This enhances the experience and may retain the child at play longer, strengthening their learning curve. Even further, some industries may benefit from the increased predictability of movement allowed by the invention, such as movement of heavy-duty machinery or robotic control. In an embodiment, the method comprises comparing said user input with reference data comprising an outcome space of possible user inputs divided into a number of groups, where at least one group corresponds to at least two possible user inputs, where each group further corresponds to a control output. Further selecting the group that the user input corresponds to, and outputting for the selected group the control output corresponding thereto, to the device to be controlled, wherein the outcome space is divided into groups based on the predefined user profile.

Thereby, control stability is increased, allowing comfortable and safe control. In addition, the exact nature of dividing into groups is specified for each individual user, whereby user preferences are satisfied that may allow some users previously unable to control a device satisfactorily to do so.

In an embodiment, the user input comprise data corresponding to a movement amplitude and / or angle, where at least one group corresponds to at least two user inputs with different amplitudes and / or angles, and where the control output corresponding to said group comprise one amplitudes and / or angle. Thereby, movement may be converted to a more stable movement, increasing user convenience. When the user is a wheelchair user, comfort and safety is increased as well.

In an embodiment, the user input comprises an input vector having an angle and an amplitude. In this embodiment, the outcome space of possible user inputs corresponds to a control area with a centre, whose area is divided among groups comprising control sectors where each control sector has a corresponding output angle. Further, the control output is produced by extending the input vector from said centre, whereby the input vector terminates in a control sector. Then, the method retrieves the output angle corresponding to the control sector, which the input vector extends into, and outputs the control output comprising the output angle. Thereby, movement may be controlled for users and situations where this is especially important, such as children playing race games, movement of disabled persons or movement of robotic equipment.

By vector is meant that the signal comprises what corresponds to an angle and an amplitude. Whether it is stored as an actual vector is not important. In addition, angle and amplitude is to be understood broadly. For example, a user may move a mouse on a screen. Here, the angle and speed of the hand of the user is interpreted intuitively as an angle and speed by the cursor on the screen. However, even wheeled or already moving systems may have their input represented by a vector. For example, a forward-left push onto a joystick controlling a wheeled unit such as a car or wheelchair, the movement will normally be expressed as turning to the left while advancing. In this case, the 'angle' correspond to a turn radius, where a high angle relative to straightforward results in a small turn radius and the amplitude corresponds to the speed produced. If the exertion is normally expressed as a coordinate in a field, this is also representable by a vector from (0, 0) to the point.

The input need not be from a single device but can for example be from a wheel and a pedal, each contributing one component of the input signal. Here vector is defined broadly to encompass both types of movement, and other movement types.

By a control area is meant a data object abstraction. In data processing terms, the input may merely be a digital signal having two values; angle and a length, where these two are used to find output values from a table; it may be two coordinates in a coordinate system, which is easily interpretable as a vector as described above. The outer boundary of the control area corresponds to the maximal possible signal transmittable from the control device, which, for joysticks, is typically the full physical displacement away from vertical. The control area will typically for joysticks be circles, while for wheels and pedals, it may be more rectangular, since the two inputs are independent of each other. Any shapes are encompassed by the invention.

In an embodiment, the centre is provided on a boundary between four control sectors or less. Thereby, a user with tremulous hands will be allowed even small amplitudes without the risk of traversing the mutual boundaries into an undesired control sector. In an embodiment, the control area further comprises one or more band modifiers being concentric circles around the centre, and where an input vector extending into a band modifier produces an output vector with a modified amplitude. Thereby, more sophisticated movement modification may be allowed for the user. In an embodiment of the invention, the band modifiers are dampening bands, where vectors extending into the bands result in output vectors with reduced amplitude or in null vectors. In an embodiment, the control area comprises an outer band modifier being a safety band extending from the outer boundary of the control area inwards, where an input vector extending into the outer safety band produces an output vector being a null vector. Thereby, users who are at risk of experiencing fits will not endanger themselves or others during a fit, as the user will push or pull very hard onto the joystick, whereby the input vector enters the outer safety band and the wheelchair stops.

In an embodiment, the control area comprises an inner band modifier being a inertial disk extending from the centre outwards, where an input vector extending into the inner inertial disk produces an output vector being a null vector. Thereby, a user with tremulous hands using a computer mouse will be able to hold a computer mouse without it moving for a certain movement range. Thereby, interacting with links, buttons and icons becomes easier or possible for such users. In an embodiment of the invention, the inertial disk is shaped as an oval and is oriented to fit the specific range and direction of motion produced in the hands of the user.

In an embodiment of the invention, the control area further comprises a trip-gearing threshold being a band modifier, where input vectors transgressing the trip-gearing threshold results in output vectors with reduced amplitude. In an embodiment, the reduction in amplitude is proportional.

In an embodiment, it further relates to a control method wherein the outcome space being divided into groups based on the user and/or user type is accomplished by a step of user specification, said step of user specification comprises providing an electronic interface device, interacting with said electronic interface device enabling modifying the reference data by modifying the number, size and/or shape of control sectors, and/or adjusting the output angles corresponding to said control sectors, and storing said modified reference data.

Thereby, a specific profile may be developed for each user. This allows changing the control sectors to effectively accommodate exactly the movement conditions of the user. In an embodiment, there is provided a plurality of predefined profiles, wherein a predefined profile is a combination of data comprised in the reference data, where said electronic device allows selection of a predefined profile for a user.

Thereby, each illness may have a predefined profile, where different settings for control sectors and band modifiers may be relevant. Persons with Parkinson's may have relatively few control sectors, where persons with epilepsy may have an outer safety band. In addition, it allows several users to use the same system where their individual profiles are stored and retrieved when they use the control device.

In an aspect of the invention, it relates to a converter device for performing the method described above. In an embodiment, it relates to a wheelchair comprising a converter device described above.

LIST OF FIGURES

In the following, example embodiments are described according to the invention, where Fig. 1 A illustrates a joystick with a converter device according to the invention, Fig. 1 B illustrates a computer mouse with a converter device according to the invention,

Fig. 1 C illustrates a console wheel with a converter device according to the invention, Fig. 2 is a conceptual drawing of the invention, Fig. 3 illustrates converting input signals to output signals according to the invention, Fig. 4 illustrates a regulation method according to the invention,

Fig. 5 illustrates a control area according to the invention, Fig. 6A - 5B illustrates a user modifiable control area according to the invention, Fig. 7A - 6C illustrates a control area with band modifiers according to the invention, Fig. 8 illustrates control sectors according to the invention, and

Fig. 9A - 9B illustrates different numbers of control sectors according to the invention.

DESCRIPTION OF DRAWINGS

In the following the invention is described in detail through embodiments thereof that should not be thought of as limiting to the scope of the invention.

Fig. 1A is a perspective view of a joystick 1 10 with a converter device 100 according to the invention. Movement of the stick 1 1 1 produces an input signal indicative of the direction the stick is pushed as well as how far it is pushed. Since the joystick will be produced with a bias pulling the stick back towards a vertical orientation, any divergence from vertical is indicative of user input. During use, some users with movement disabilities will be unable to control the amount of pressure applied to the stick 1 1 1 precisely as well as a precise direction of this pressure. Traditionally, this results in a signal that varies significantly over time. If a wheelchair is operated by this signal, the user will experience discomfort, as his /her body is shaken from side to side or accelerated and decelerated alternatively.

When the signal is transmitted from the joystick, it passes through a converter device 100. In the converter, the signal is converted to produce a straight movement. The conversion itself will be described later. Conveniently, the converter device 100 is located inside the body of the joystick 1 10.

Fig. 1 B is a perspective view of a computer mouse 1 10' with a converter device according to the invention. Persons with tremulous hands may have difficulty especially with fine motoric tasks, such as keeping the cursor over an icon or link prior to clicking it. By allowing the mouse to not move within a certain amplitude threshold, this may be significantly easier for such a person. Children may also more easily navigate using a mouse having quite coarse directional restrictions, perhaps converting all movement to one of eight directions.

Fig. 1 C illustrates a console wheel with a converter device according to the invention. By using the converter device 100 with a console wheel 1 10", steering control is achieved where people with less than optimal coordination may be helped manoeuvre. This may for example be small children who will often oversteer, swinging wildly from side to side to compensate for their errors. They may then be discouraged for failing, where a converter device may help them steer better.

Fig. 2 illustrates the concept of the invention. A user input is provided to the converter device 100. Here it is assessed based on a predetermined user profile to produce a control output. The predefined user profile is created ahead of time e.g. using an electronic interface and with basis in knowledge of the specific movement condition of the user. Thereby, a user profile may be created that exactly matches the needs of the user, reducing the impact of poor motoric powers of the user while retaining as much control as possible. For example, a user with tremulous hands may have hands that shake from side to side but where the user retains relatively precise control over his/her backwards/forwards motion. A user profile for this person may have large side-ways tolerances and only small forward/backward tolerances, allowing precise control according to his/her specific situation.

Another example is a child playing a game or driving a wheelchair, where the child substantially always uses full exertion or no exertion and has poor coordination skills to use intermediary degrees of exertion. Here, the profile for the child might reduce the amounts of different degrees of motion, so only eight angles of motion is possible, which affords predictable motion for the child.

A third example is a user who has a risk of having fits. Here, using full exertion is indicative of a fit, where for this user this should produce no motion and perhaps transmit a prompt to a caretaker. Fig. 3 illustrates conversion of user inputs, denoted inputs A through L, to control outputs, denoted outputs U through Z. The input received from the input device 1 10 can take a variety of values. These inputs may for example take the shape of the position of a stick of a joystick or the change in position of a computer mouse.

Conventionally, the user input is inputted directly into the device to be controlled. According to the invention, the signal fidelity may be reduced or changed so that fewer or different outputs are communicated to the system to be controlled, providing a more stable control. For example, on the left-side column of fig. 2, inputs A through C all correspond to group N, for which there is a single output U. A user may in other words provide a series of different values to the converter but produce the same motion or command.

Outputs U through Z may have a character dependent on the inputs A through L. If the inputs relate to different speeds, then outputs preferably, but not necessarily, relate to different speeds as well. In the case of both input and output relating to speed, it allows smooth and stable control thereof, where thresholds must be transgressed to change the speed, such as changing from producing input I to producing input J. Inputs and outputs may then relate to a speed, an angle, both, or some other aspect of control such as rotation or execution of commands not relating to movement.

The groupings and the control outputs may be specifically tailored to each individual user. For example, user I and II have different groupings, where group N for user I corresponds to inputs A through C, and where group N for user II corresponds more broadly to inputs A through E. This may be because user II has tremulous hands and user I is a child at play.

The groups may be different as well. User I has groups N, O, P, Q, R, while user II has groups N, O, P, S, T. When specifying user profiles, a series of predefined profiles may exist as well as predefined groups having specific effects. If for example user II has a risk of having fits, it may be known that s/he will produce input L, where group T produces an output Z and further produces an alert for a caretaker.

The number of groups and the specific outputs may vary among users as well. Fig. 4A illustrates an embodiment of the invention, where an interpretation of movement according to vectors is taken. As the input signal is passed through the converter device 100, it is converted according to the control area 400. The outer boundary of the control area corresponds to a maximal exertion of a control device, whereby the control area corresponds to the full range of possible control signals of the device. The control area comprises a number of control sectors 41 1 ^N, where in the embodiment shown in Fig. 4A, these sectors 41 1 ^N are substantially rectangular, with curved edges where they meet the boundary of the control area. The input vector is arranged from the centre 401 of the control area 400, and may have an angle and amplitude as indicated by the arrow 402. This places the far end of the input vector in a control sector 41 1 .

By having substantially rectangular control sectors, the centre of the control area then has only two directions abutting. This allows better control for users whose movement disabilities does not relate to how hard they press or pull on the joystick.

Figs. 4B and 4C illustrate an example regulation performed according to the invention. In fig 3B, the input vector 402' is slightly to the right of a straightforward motion. This is then converted to an output vector 322 being straightforward. In Fig. 4C the input vector is now substantially to the right of a straightforward motion. However, as the input vector still extends into the same control sector, the angle of the motion is corrected to have an angle identical to the one mentioned and shown in Fig. 4B. As users with tremulous hands may thus swerve from side to side, the invention allows them to operate a device by correcting all signals within a range to a single output value as regards the angle. Looking now again at figs. 4A and 4D, an input vector extending into the control sector 41 1⁴ produces an output angle facing forwards, whereas an input vector extending into control sector 41 1² produces an output vector 422² of forty-five degrees left-wards. An input vector 402 extending into control sector 41 1¹ produces an output vector 322¹ being sideways. Thereby, possible angles are reduced to a number equal to the number of control sectors. In other embodiments, any different number of control sectors may be present.

The directions described for figs 4B and 4C are for a wheelchair moved by a converter device 100 according to the invention. If a computer mouse moves a cursor, forwards motion and rearwards motion may be substituted for upwards motion and downwards motion.

A user who trembles in his/her hand may then still drive straight ahead with a converter device according to the invention. When the user wishes to change direction, s/he then exerts coarse motoric skills and pushes against the control device to get the input vector into the neighbouring sectors such as between sectors 41 1⁴ and 41 1 ^s. This may be significantly easier for a user. For example, some users will have tremors in their hands but still be able to push extremely hard onto the control device, such that they operate substantially along the outer boundary of the control area. When such a user pushes the control device against the boundary, this boundary supplies some support whereby the user may more easily adjust the direction.

Fig. 5 illustrates a regulation method according to the invention. An input signal 512 is provided, comprising as least an angle from 0 degrees to 360 degrees and an amplitude from 0% to 100% of a maximal length according to the device or signal type. Sensing the input vector 521 is performed conveniently through a control device such as a joystick 1 10.

The input signal 512 is assessed against reference data 513 in the step of vector assessment 501. Vector assessment 501 comprises extending the input vector 402 from the centre 401 of the control area 400, and where the end of the input vector extends into a control sector 41 1 of the control area.

When the control sector has been identified, an output signal is generated in the step of output signal generation 502. The amplitude of the input vector 402 is maintained while the angle is substituted for an output angle. The output angle is comprised in the reference data and there is an output angle for every control sector.

For some embodiments of the invention, the output signal generation 502 may produce output signals not being merely output vectors but other types of output signals, such as corresponding to button presses or full stops.

The reference data 513 comprises a control area 400 further comprising control sectors. Reference data 513 further comprise a series of output angles 322^N each mapped specifically to a control sector 41 1 ^N. The control area 400 may be a standard circle with standard control sectors set at production of the converter device. Preferably, however, the reference data may be modified and is thus user specific. This is preferable as handicaps differ significantly, so that a control area useful for one user may be unsuited for another user. Thereby, reference data modification 522 is the process whereby the reference data is fine-tuned to an individual user.

Further, the reference data may comprise circle band modifiers. These circle band modifiers are concentric circles around the centre 401 , and will be further described in relation to Fig. 7.

Figs. 6 - 9 illustrate various embodiments of the control area according to the invention.

Fig. 6A - 6B illustrates a user modifiable control area according to the invention. In this embodiment, the control area is modifiable for example by a caretaker. A user is placed with or in the intended control device such as a joystick or a computer mouse, and by trial and error different tasks are performed. Meanwhile, the caretaker easily modifies the control area with an external device such as a smart device, where a visual version of the control area may be shown. The caretaker may then move control sector boundaries 501 to a different position 501 ' to better accommodate the specific handicaps of the user. Thereby, a person with only slight handicaps may get with a converter device having more control sectors and thus a larger range of options, where a person with very severe movement handicap may have a very simple control area with only very few control sectors, such as four sectors. Even though the embodiment illustrated only describes the movement of boundary 501 , it is to be understood that changes may relate also to the number of control sectors, the shape of control sectors and to the circle band modifiers described in Fig. 6.

Fig. 7A illustrates a control area with an outer safety band 701 according to the invention. Having an outer safety band is useful for users who may enter a fit, such as epileptics. Thereby, during a fit, the input vector will extend into the safety band and movement is nullified for the output signal, whereby the controlled device such as a wheelchair stops. Using such an outer safety band in a wheelchair is conveniently accompanied by increasing the inertia for the same very outermost region of the joystick, whereby during normal operations, the user will not push the stick into the safety band even at what may be thought of as fully pushing onto the joystick.

Fig. 7B illustrates a control area with a trip-gearing threshold 702 according to the invention. Users may endeavour on extended drives on uneven surfaces, where an otherwise acceptable speed at for example 80% of full speed is unsafe or unpleasant to the user. In these specific circumstances, a caretaker may add a trip gearing, whereby the user cannot drive at these too high speeds. At a certain percentage of full speed such as 70%, a gearing of for example half may be employed. Thereby, when the user passes this threshold, the speed of the wheelchair decreases to 35% of full speed and may then increase to 50% at the outer boundary of the control area. The location of the trip gearing may be adjusted by the caretaker who may also adjust the actual gearing hereof. In an embodiment, several such gearings may be used. Fig. 7C illustrates a control area with an inertial centre 703 according to the invention. An inertial centre allows a user to not move when the input vector extends only into the inertial centre 703. This may be especially useful for controlling a computer mouse. A user may then retain a cursor over a link or icon and click it even with tremulous hands. In an embodiment, the inertial centre is oval, square or rectangular. In an embodiment where the inertial centre is not a circle, such as when it is an oval, the inertial centre 703 may be rotated to correspond to the actual region of the tremulous movement of a user. Thereby, the user may still move the cursor in any other direction without inertia.

Fig. 7 illustrates pie-shaped control sectors according to the invention. Thereby, a user whose tremors in the hands increases with the effort of pushing a joystick may retain increased control for very small exertions onto the control device.

Fig. 9A - 9B illustrates different numbers of control sectors according to the invention. Fig. 9A illustrate a control area with six control areas. Thereby, a person with very limited control may control a wheelchair. Fig. 9B illustrate a control area with twelve control sectors. Thereby a user having substantial control in his/her hands may retain several movement options.

Claims

1. A method for converting a user input to a control output for controlling movement of a device, the method comprising:

2. A method according to claim 1 , wherein said method of converting, based on a predefined user profile, comprises:

- comparing said user input with reference data comprising an outcome space of possible user inputs divided into a number of groups, where at least one group corresponds to at least two possible user inputs, where each group further corresponds to a control output,

- selecting the group, which the user input corresponds to, and

- outputting for the selected group the control output corresponding thereto, to the device to be controlled,

- wherein the outcome space is divided into groups based on the predefined user profile.

3. A method according to any of the claims 1 - 2, wherein the user input comprises data corresponding to a movement amplitude and / or angle, where at least one group corresponds to at least two user inputs with different amplitudes and / or angles, and where the control output corresponding to said group comprises one amplitudes and / or angle.

4. A method according to any of the claims 1 - 3, wherein:

- the user input comprises data corresponding to an input vector (402) having an angle and an amplitude,

- where the outcome space of possible user inputs corresponds to a control area (400) with a centre (401 ) whose area is divided among groups corresponding to control sectors (41 1 ^N) where each control sector (41 1 ) has a corresponding output angle (322), where said control output is produced by

- extending the input vector (402) from said centre (401 ), whereby the input vector terminates in a control sector (41 1 ), - retrieving the output angle corresponding to the control sector (41 1 ), which the input vector extends into, and

- outputting the control output comprising the output angle.

5 5. A method according to claim 4, wherein the centre (401 ) is provided on a boundary between four control sectors (41 1 ) or less.

6. A method according to any of the claims 4 - 5, wherein the control area further comprises one or more band modifiers being concentric circles around the centre 401 ,

10 and where an input vector extending into a band modifier produces an output vector with a modified amplitude.

7. A method according to claim 6, wherein the control area comprises an outer band modifier being a safety band extending from the outer boundary of the control area

15 inwards, where an input vector extending into the outer safety band produces an output vector being a null vector.

8. A method according to any of the claims 6 - 7, wherein the control area comprises a band modifier being an inner inertial disk extending from the centre 401 outwards, where

20 an input vector extending into the inner inertial disk produces an output vector being a null vector.

9. A method according to any of the claims 4 - 8, wherein the outcome space being divided into groups based on the user and/or user type is accomplished by a step of user

25 specification (522), said step of user specification comprising

- providing an electronic interface device,

- interacting with said electronic interface device enabling modifying the reference data (513) by

- modifying the number, size and/or shape of control sectors (41 1 ^N), and/or 30 - adjusting the output angles corresponding to said control sectors, and

- storing said modified reference data (513).

10. A method according to claim 9 and any of the claims 6 - 8, wherein modifying reference data (513) further allows modifying number, size and/or shape of band modifiers (701 ,

35 702, 703).

1 1 . A method according to any of the preceding claims, wherein a plurality of predefined profiles are provided, wherein a predefined profile is a configuration of reference data (513), where said electronic device allows selection of a predefined profile for a user.

12. A converter device for performing the method described in claims 1-1 1 .

13. A wheelchair comprising a converter device according to claim 12.