WO2014006525A2

WO2014006525A2 - Lighting system for workstations.

Info

Publication number: WO2014006525A2
Application number: PCT/IB2013/055098
Authority: WO
Inventors: Gary Nelson Garcia Molina; Mark Christoph Jaeger; Arnd Ritz; Tsvetomira Kirova TSONEVA
Original assignee: Koninklijke Philips N.V.
Priority date: 2012-07-05
Filing date: 2013-06-21
Publication date: 2014-01-09
Also published as: WO2014006525A3

Abstract

The invention relates to a method and a lighting system (100) for at least one workstation (13a,13b,...) at which steps of a production process are executed. Lamp(s) (12a,12b,...) at these workstation(s) (13a,13b,...) are controlled according to one or more of the following criteria: (a) the workflow of the process, (b)the requirements with respect to cognitive performance, motor skills and/or attention of a user (U) at the workstations, and/or (c) the performance of the process. The approach allows for example to achieve a conditioning of the user (U) by associating particular lighting conditions to a certain level of cognitive performance, motor skills, and/or attention.

Description

Lighting system for workstations

FIELD OF THE INVENTION

The invention relates to a method for illuminating at least one, preferably a plurality of workstations at which at least one step of a production process is executed, and a lighting system suited to providing the required illumination

BACKGROUND OF THE INVENTION

The US 2007/0258243 Al discloses a flexible lighting system for delivering a dynamic, fully customized, and automatic illumination to a subject. Parameters like the spectrum or intensity of the emitted light are adapted depending on the tasks to be performed and/or on personal characteristics of the user.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide a method that allows for an improved illumination of a production process consisting of at least one, preferably a plurality of steps or tasks.

This object is achieved by a method according to claim 1 and a lighting system according to claiml3. Preferred embodiments are disclosed in the dependent claims.

The method according to the present invention is intended for illuminating at least one, preferably a plurality of workstations at which at least one step of a production process is executed. The method comprising controlling at least one lamp at the at least one work station according to one or more of the following criteria;

- a performance level of the at least one step of the production process,

- a time of day,

- a time of year,

- a level of illumination of the surroundings,

- a noise level of the surroundings,

- a preference of a user,

- a physio -bio logical state of the user,

- a workflow of the production process, and - a requirement of the production process with respect to a cognitive performance, motor skills, and attention or any combinations thereof, of the user at the at least one workstation

The "process" mentioned above and the "steps" of the process may quite generally comprise activities and manipulations executed by a user, for example during work or leisure time.

The "workstations" are in a general sense different locations in space that have to be illuminated such that a user can execute the step that is intended for this station.

The steps at different workstations may be independent of each other, (at least partially) be identical to each other, linked to each other, or comprise any combination of these possibilities. If the process comprises for example the manufacturing of some article, the steps may correspond to consecutive manufacturing phases.

The term "lamp" as used here shall denote one light source or a set of light sources that is controlled by the method and is intended for illuminating at least one workstation. Controllability of a lamp comprises for example that its light source(s) can be switched on or off. Preferably, a more elaborate control with respect to various parameters of the light output is possible.

The "control unit" may be realized in dedicated electronic hardware, digital data processing hardware with associated software, or a mixture of both. There may be several control units, particularly one control unit for the at least one lamp of at least one workstation, wherein these several control units may optionally be interconnected for an exchange of information and/or energy.

The invention further relates to a lighting system for illuminating at least one, preferably a plurality of workstations at which at least one step of a production process is executed, comprising;

- at least one lamp for illuminating the at least one workstation, and

- at least one control unit,

- wherein the at least one control unit is adapted to control the at least one lamp at the at least one workstation according to one or more of the following criteria;

- a performance of the process,

- a time of day,

- a time of year,

- a level of illumination of the surroundings, - a noise level of the surroundings,

- a preference of the user,

- a physio -bio logical state of the user,

- a workflow of the production process, and

- a requirement of the production process with respect to the cognitive performance, motor skills, and attention or any combinations thereof, of the user at the at least one workstation.

The method and the lighting system are based on the same inventive concept, i.e. the control of at least one lamp at the at least one workstation according to criteria related to the workflow, the requirements at the at least one workstation and/or the performance.

Explanations and definitions provided for the method are therefore also valid for the lighting system and vice versa.

The method and the lighting system have the advantage that they allow for a flexible illumination of at least one, preferably a plurality of workstations that is adaptable to the needs of a human user. Thus an optimal performance of the at least one process step to be executed at the at least one workstation can be achieved.

In the following, various preferred embodiments of the invention will be described that relate both to the method and the lighting system described above.

The at least one, preferably a plurality of workstations may be associated to subsequent steps of the process. An object of the process, for example an article to be manufactured, will then typically be passed from one workstation to the next according to the process sequence of steps.

According to a preferred realization of the aforementioned embodiment, the subsequent steps of the process are intended to be executed by the same user. Accordingly, this user will proceed from workstation to workstation when executing the steps of the process in their intended sequence. When the illumination at the workstations is controlled with respect to the requirements of cognitive performance, motor skills, and/or attention, this is advantageous for such a user because she/he automatically gets the appropriate lighting for the task at hand.

In general, any parameter that has an influence on the light output of the at least one lamp can be controlled by the method or the lighting system. Most preferably, at least one of the following parameters of the light output is controlled: a brightness, an intensity, a spectral composition (colour, colour temperature etc.), a polarization, a timing, and/or a flickering of the light. These parameters may be controlled globally or spatially resolved (i.e. dependent on position in space and/or on a direction of emission). The

"flickering" particularly refers to a wavelike modulation of intensity or some other parameter of the light output, for example according to an on/off sequence with a frequency between about 0.1 and 100 Hz.

The control according to the workflow of the process depends on parameters that define said workflow, for example the order, interrelation, and/or temporal schedule of process steps. In a particular embodiment, this control comprises the change of illumination conditions at the at least one workstation in dependence on the intended duration of the step executed at said workstation. The illumination at the at least one workstation can in this case support the temporal coordination of process steps and the adherence to an intended schedule.

In another embodiment, the control according to the workflow of the process comprises that the current lighting conditions at the at least one workstation are changed at the end of a step towards new lighting conditions which correspond to the subsequent step that shall be executed at this or at another workstation. This change "at the end" of a step may particularly comprise a change that begins already while the current step has not yet completely be finished. Moreover, a change "towards new lighting conditions" means that all or some of the parameters of the new lighting conditions are adopted. The change of the lighting conditions at the end of a step can prepare the user at the workstation (consciously or unconsciously) for the subsequent step.

The control unit may particularly comprise a user interface, for example a keyboard, via which requirements with respect to one or more of the following criteria;

cognitive performance of the user, motor skills of the user, and/or attention of the user can be input. Corresponding data can for example be provided by a process engineer after analysis of the production process and its individual steps.

The control of the at least one lamp with respect to the requirements of one or more of the following criteria; cognitive performance of the user, motor skills of the user, and/or attention of the user may exploit any parameter of light output or lighting conditions that has a known effect on these parameters. In particular, an increase in the requirements (cognitive performance, motor skills, and /or attention) may imply a higher intensity and/or a blue-enrichment of the light output of the corresponding at least one lamp.

The control of the at least one lamp according to the performance of the production process may preferably be dependent on the output and/or the error-rate of the process (on the whole or at a particular workstation). This approach is particularly suitable if a measure of the output or the error-rate can automatically be gained, for example by counting the produced articles or defect articles that were rejected by a quality control. A decreasing output or an increasing error-rate may for example be mitigated by the control unit with an increase in light output parameters which thus increases the attention of the user at the respective workstation.

The control of the at least one lamp at the at least one workstation may further comprise controlling the at least one lamp according to further criteria. For example, the control of the at least one lamp may further comprise controlling the at least one lamp according to one or more of the following criteria; an age of the user, a gender of the user, and/or a history of the user.

The aforementioned history of a user may for example comprise information about the working activity of said user during the current working day and/or during the user's life. Working activity during the current working day allows, for example to take into account if a user is fatigued, or if she/he returns from a break (both these situations may require a lighting condition that increases the attention of said user). Working activity during the life of the user may provide information about her/his professional skills.

In one embodiment of the invention, the control of the at least one lamp may comprise controlling the at least one lamp according to one or more of the following criteria; a time of day, a time of year (season), a general level of illumination in the surroundings, anda noise level in the surroundings. All these parameters may have an influence on the performance of a user at the at least one workstation, which can in turn be taken into account for establishing optimal illumination of said at least one workstation.

In a further development of the invention, wherein the step of controlling the at least one lamp further comprises an at least one control unit, wherein the at least one control unit is configured to adapt or learn its control behaviour, in particular with respect to the objective of process performance. Most preferably, this adaptation takes place in a user-specific manner, i.e. an individual set of optimal control parameters may be assigned to each user. The adaptation or learning may take place automatically if there is some suitable performance criterion (e.g. the article output or error-rate at a particular workstation).

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

In the drawings: Fig. 1 schematically illustrates a lighting system for at least one, preferably a plurality of workstations according to the present invention;

Fig. 2 schematically illustrates the conditioning effect that can be realized with a lighting system according to the present invention.

Like reference numbers refer in the Figures to identical or similar components.

DETAILED DESCRIPTION OF EMBODIMENTS

Virtually all production processes are based on the division of labour amongst workers with specialized skills. As nobody can bear to do the same work step all day long production is mostly organized such that every worker repeatedly completes a limited series of steps from the total process. This means that the worker is confronted with a succession of steps or tasks that demand different levels of attention, motor skills and cognitive

performance. To be successful the worker has to constantly adjust her/his mindset and attitude to the right mental and physical state for the execution of a given task. Due to the repetitive nature of the labour the employee has to work against fatigue, negligence and perception of monotony. Moreover series of repetitive tasks are prone to omission errors.

In order to address the above issues, it is proposed to use dynamic light settings adapted to the demands of the different work steps to enhance productivity and quality of work. The visual separation of the individual production steps increases motivation helps to set the right state of mind and supports alignment to the rhythm of the workflow.

Figure 1 schematically illustrates a lighting system 100 that is intended for lighting at least one, preferably a plurality of workstation sl3a, 13b, ... at which a user U (or several users) performs steps or tasks of an overall production process. In the shown example, these steps shall be subsequent steps to be executed with an article of manufacture in an industry context.

The setup of all workstations is in principle identical and therefore in the following described with respect to the particular workstation 13a. This workstation 13a is illuminated by a lamp 12a. The lamp 12a may comprise one or more light sources like LEDs, incandescent lamps, halogen lamps or the like. The light output of the lamp 12a (i.e. the individual light output of its light sources) is controlled by a control command c which is issued by a control unit 11a. To determine the command c, the control unit 11a takes into consideration a plurality of inputs, in particular:

- An input signal t about the task (or step) that has to be done at the

workstation 13a. This signal comprises for example information about the particular requirements of the task in terms of cognitive/motor ability. For example, the brightness of the illumination in precision-tasks may be set to higher values. Moreover, the signal t may comprise information about the requirements of the task in terms of timing. In this case, light can help in maintaining the pace.

- An input signal w about the user U at the workstation 13 a, for example her/his age, gender, history, professional skills etc. For instance, the alerting properties of light (luminance and colour) can be changed depending on a worker's shifting history.

- An input signal p about performance related information, for example a performance measure indicating the present process output or execution speed (articles per unit of time), the accuracy, or some type of error-rate (rejected articles per unit of time). If the performance is going down for example, less parts are produced or more rejects are detected. To remediate this, the light setting can be adapted, for example by increasing the brightness level (cf. S. Lehrl et al, "Blue light improves cognitive performance", Journal of Neural Transmission, vol 114, pp. 457-460, 2007).

- An input signal e about external or contextual information like the time of the year (season), the time of day, or the noise level. For instance, after a break the light intensity may be increased to help the person get faster back to work or avoid lapsing attention during nightshirts.

The above mentioned parameters are received as input by the control unit 11a of a particular task to determine via the command c lighting parameters such as:

- Timing, i.e. for how long a particular lighting setting has to be maintained. Alternating settings are also possible.

- Colour temperature.

- Luminance.

- Flickering effects. Flickering in this context can be used to enhance a worker's cognitive ability or to draw her/his attention on important details of the task. Timely applied flickering light has been shown to have a positive influence on memory.

It is known from literature that light can positively influence cognitive abilities of persons. For example it has been shown that high intensity blue-enriched white light can increase the alertness level of a person (G. Vandewalle, P. Maquet, and D.-J. Dijk, "Light as a modulator of cognitive brain function", Trends in Cognitive Sciences, vol. 13, no. 10, pp. 429-438, 2009). The control units 11a, 1 lb, ... in the lighting system 100 of Figure 1 may hence automatically personalize the light settings based on - the cognitive and motor abilities needed to perform the manufacturing task

(signal t),

- (real-time) feedback from the performance measure p (e.g. number of produced parts, number of rejects), and

- other context information such as time of day.

For each subtask in a manufacturing process the necessary cognitive abilities are selected through a user interface (e.g. by engineers optimizing the manufacturing process). Based on the entered cognitive abilities, the optimal light settings are automatically chosen by the control unit(s). For example in an electronic assembly line putting small parts together requires a high attention ability of the worker. Increasing the light intensity and changing the colour temperature towards blue can help to stimulate the alertness and concentration level of the worker.

In a further development, the control units can be designed to learn and store the optimal light settings for each worker to achieve the best performance outcome while providing the most energy efficient solution.

As workers experience the dynamic nature of the lighting settings for particular tasks and cognitive or motor skill demands, it is expected that the next time they experience similar settings they would automatically set their mindset to the execution of the task. This is due to the conditioning effect of light, which will be described in more detail in the following.

The phenomenon of conditioning is highly prevalent in our environment because of constant learning of associations between events or behaviours and environmental clues. For instance humans are not born with the association between the red colour and the fact of stopping. Through the course of life observing and experiencing stop signs, stoplights or brake lights, we begin to consciously and subconsciously associate the red colour with stopping.

Similarly, light with different properties can be used to condition certain cognitive or motor skill demands required by a manufacturing task. This works in two phases, namely association "A" and priming "P" of the mental state, which are illustrated in Figure 2.

In the association phase(s) A, specific light settings can be chosen for a particular manufacturing task. In this way, the association between these settings and the task is established. In Figure 2, the association phases A are illustrated by the use of different light settings for manufacturing tasks Tl and T2, respectively. The next time workers experience similar light settings it is expected that their mindset would automatically be set on the execution of the task due to a conditioning effect. The association phase can be repeated multiple times to increase the strength of the association between the light settings and the task.

In the priming of the mental state phase (simply referred to as priming P), the light settings previously associated with the specific manufacturing tasks are delivered prior to the task execution. This activates the mental state and brain activity configuration established in the association phase and thus prepares the worker for the task. In Figure 2 it can be observed that while a worker is executing task Tl (resp. T2) and the light settings for task T2 (resp. Tl) are rendered, the worker mentally prepares to the execution of the new task.

Association phase A and priming phase P can be also interleaved to strengthen the effect. After a single association, priming can start already. Association and priming can then be adapted to enhance the effect.

The advantage of this process is twofold as it affects the user both unconsciously by conditioning certain cognitive or motor skill required by the task, and consciously by actively catching the attention of the worker and communicating the change of task. Even before starting a task, the individual (by perceiving the lighting settings) can be put in the mental state that is more suitable to the execution of the task.

The conditioning also means that any lighting setting can favour the performance of a particular task. Existing light systems can therefore be re-used by updating the lighting control systems, and light settings can as well fulfil existing boundary conditions (e.g. for clean rooms UV filters have to be used) provided that an association exists between the performance of the task and the lighting setting.

The invention also offers the possibility of varying the lighting settings associated with high performance in a particular task by creating a new association. This certainly constitutes an advantage against monotony and habituation.

In summary, the invention can inter alia be applied in manufacturing processes that are decomposed in a series of tasks, which may be executed in different locations and by different workers. The nature of the tasks can be different in terms of complexity and duration. These determine the level of cognitive engagement required to successfully complete a given task.

The present invention proposes to use different illumination settings for each task with the goal of influencing the cognitive performance, motor skills, or attention according to the particular demands of the task, the person performing the task (personalization), and other context information (such as time of the day or season). Using different light settings for different tasks benefits the workflow because it guides the sequence of tasks and can reduce the incidence of omission errors. In the case of

manufacturing processes that include repetitive and tedious tasks, dynamic light settings can help in enhancing the working environment and diminish the perception of monotony. The system delivers light of specific properties to put the user in a specific (relevant) brain state, boost specific ability and/or enhance the visibility of specific task related details. The approach further allows achieving a conditioning of a user by associating particular lighting conditions to a certain level of cognitive performance, motor skills, and/or attention.

The proposed lighting system and method have the following advantages:

- To raise productivity by supporting perception and cognition tasks by lighting settings adapted to the specific demands of the different work steps.

- To increase production quality by preventing omission errors.

- To reduce fatigue and perception of monotony in repetitive tasks.

- To enhance overall job satisfaction of employees by individualization of their work environment.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A method for illuminating at least one workstation at which at least one step of a production process is executed, the method comprising controlling at least one lamp at the at least one workstation according to one or more of the following criteria;

- a workflow of the production process,

- a requirement of the production process with respect to a cognitive performance, motor skills, and attention or any combinations thereof, of the user at the at least one workstation, and

- a performance level of the at least one step of the production process.

2. The method according to claim 1, wherein the step of controlling the at least one lamp further comprises controlling the at least one lamp according to one or more of the following criteria;

- a time of day,

- a time of year,

- a level of illumination of the surroundings,

- a noise level of the surroundings,

- a preference of a user,

- a physio -bio logical state of the user,

3. The method according to any preceding claim, further comprising:

- providing multiple workstations and arranging the multiple workstations for executing subsequent steps of the production process.

4. The method according to claim 3, further comprising executing at least two subsequent steps of the production process by the same user.

5. The method according to any one of the previous claims, wherein the step of controlling the at least one lamp comprises controlling at least one of the following parameters of the light output of the lamp;

- a brightness,

- an intensity,

- a spectral composition,

- a polarization,

- a timing, and

- a flickering.

6. The method according to claims 1 and 2, wherein the step of controlling the at least one lamp comprises controlling a lighting condition at the at least one workstation in dependence on the intended duration of the production process step executed at the workstation.

7. The method according to claims 1 and 2, wherein the step of controlling the at least one lamp comprises controlling a lighting condition at the at least one workstation as a function of a lighting condition at a subsequent work station.

8. The method according to claims land 2, wherein the step of controlling the at least one lamp comprises adjusting a higher intensity and/or a blue-enrichment of the light output of the corresponding at least one lamp.

9 The method according to claims 1 and 2, wherein the step of controlling the at least one lamp further comprises controlling the at least one lamp according to one or more of the following criteria;

- an output of the production process, and

- an error-rate of said production process.

10. The method according to claims 1 and 2, wherein the step of controlling the at least one lamp further comprises controlling the at least one lamp according to one or more of the following criteria;

- an age of the user,

- a gender of the user, and - a history of the user.

11. The method according to claim 10, wherein the step of controlling the at least one lamp further comprises controlling the at least one lamp according to one or more of the following criteria;

- a working activity of the user during the current working day, and

- a working activity of the user during the working life of the user.

12. The method according to claims 1 and 2, wherein the step of controlling the at least one lamp further comprises an at least one control unit wherein the at least one control unit is configured to adapt or learn its control behaviour, particularly with respect to the objective of production process performance.

13. The method according to claims 1 and 2, wherein the step of controlling the at least one lamp further comprises controlling the at least one lamp according to one or more of the following criteria;

- a conditioning of the user by associating particular lighting levels with a certain level of cognitive performance,

- a conditioning of the user by associating particular lighting levels with a certain level of motor skills, and

- a conditioning of the user by associating particular lighting levels with a certain level of attention.

14. A lighting system for illuminating at least one workstation at which at least one step of a production process is executed, comprising:

- at least one lamp for illuminating the at least one workstation, and

- at least one control unit,

- a workflow of the production process,

- a requirement of the production process with respect to the cognitive performance, motor skills, and attention or any combinations thereof, of the user at the at- least one workstation, and

- a performance of the process.

15. The lighting system according to claim 14, wherein the illumination of at least one workstation at which at least one step of a production process is executed, further comprising - at least one lamp for illuminating the at least one workstation, and

- at least one control unit,

- a time of day,

- a time of year,

- a level of illumination of the surroundings,

- a noise level of the surroundings,

- a preference of a user,

- a physio -bio logical state of the user, and

- a workflow of the production process.