EP0450426A1 - Method for generating a signal to attract attention - Google Patents

Abstract

A signal is generated with a plurality of states which occur repeatedly over the course of time. In order to prevent reduced attention by the observer resulting from habituation, the period of time during which one or more of the states occurs is determined randomly or pseudo-randomly, in each case, by means of a suitable circuit. The random period can be restricted by adjustable upper and/or lower limiting values.

Description

It is known to make signals that are intended to draw attention to be perceptible either by a static or by a periodic display. So to speak, one of these two types of display is used, regardless of whether the display is mechanical (by stationary or moving pointers, colored discs, etc.) acoustically (by buzzing, whistling, bell chime) or optically (by warning light, hazard lights, traffic lights, in particular, or by means of a lighthouse identifier). Such advertisements all serve their purpose, provided that a certain professional attention can be expected from the person addressed. Wherever reduced vigilance is to be expected, a periodically flashing display (e.g. yellow turn signals for traffic lights or red flashing warning lights for endangered equipment) has generally proven itself. In situations that repeat themselves very often and thereby partially lose their alarm character, a periodic signal can also lead to habituation and thus to disregard, as is known to some users of alarm clocks with alarms repeated at fixed intervals. A similar problem arises with systems for regulating traffic, particularly in densely populated areas, where they occur frequently enough to go unnoticed on a case-by-case basis, especially in slow or light traffic.

The aim of the invention is to counteract this habituation effect. To this end, the invention is defined as described in claims 1 and 7.

In the following, the invention will be explained in more detail on the basis of exemplary embodiments and the drawing. For the sake of clarity, the expression "random or pseudo-random" has been replaced throughout by the simple term "random". For more information on random and pseudo-random consequences see e.g. U. Tietze and Ch. Schenk: "Semiconductor circuit technology", Springer 1976.

• Figuren 1a, 1b die Zeitdiagramme von zwei Ausführungsformen der Erfindung,
• Figur 2 das Zeitdiagramm einer weiteren Ausführungsform,
• Figur 3 das Blockschaltschema einer Schaltung zur Durchführung der Erfindung, und
• Figur 4 zeigt ein teilweises Flussdiagramm zur Steuerung der Schaltung der Figur 3.

It shows:

• FIGS. 1a, 1b show the time diagrams of two embodiments of the invention,
• FIG. 2 shows the time diagram of a further embodiment,
• Figure 3 shows the block diagram of a circuit for carrying out the invention, and
• FIG. 4 shows a partial flow chart for controlling the circuit of FIG. 3.

Figure 1 shows the timing diagram of a preferred simple embodiment of the invention, in which only two different states of the signal generator are generated. This can be, for example, the light and dark state of a yellow flashing light in road traffic, but equally well two different intensities of a light signal of any color, for example in rail traffic, the "ringing" and "silent" states of an alarm clock or two different tones of an alarm siren. These states are simply labeled O and 1 in the diagram, although they do not have to refer to an on and an off state. For example, the states corresponding to the designations O and 1 can correspond to an intensive and a weak phase of a single signal lamp, but equally well to an alternating yellow and orange light or the lighting up of one of two same-colored, adjacent lights of the same color. The abscissa t in the diagram represents time.

In the example from FIG. 1a, the duration of state 1 is limited downwards by the fixed value A each time it occurs. At this value comes a randomly selected time interval B 1, B 2, B 3 ... every time state 1 occurs. As a rule, the length of this time interval is set to an upper limit, designated B₀ in FIG. 1a. In contrast to state 1, state O in FIG. A has an adjustable but fixed value R.

In the example in FIG. 1b, both states have an adjustable minimum duration A or R, to each of which a randomly selected duration B _i or S _{i is} added, which is limited by the adjustable values B₀ or S₀.

Of course, in addition to the time sequences shown in FIG. 1, numerous other combinations of limited and / or unlimited state sequences are possible, but these need not be described in detail here. For example, after a fixed or randomly determined number of state changes (or after a specific time), a limited number of states with an unchanging duration could be inserted, if this appears advantageous.

Figure 2 shows the timing diagram of a signal generator with four states: light green, dark green, light red, dark red. It always alternates a pair of light and dark states of one color with the same pair of states of the other color. For the sake of simplicity, it was assumed that all status pairs of the "green" variety have the same duration G and all those of the "red" variety have the same duration R, although this is of course not necessary. Within each pair, the duration of the first state H _i or S _{i is} chosen randomly between zero and the possible maximum value G or R. As a result - without changing the color of an optical signal - the viewer's attention is drawn more strongly to this signal, which in some cases can be limited to a single color, usually red.

The signal sequences described with reference to FIG. 1 or 2 can be generated, for example, by a circuit whose block diagram is shown schematically in FIG. 3. A central data processing unit (CPU) 1 is powered by a power source (not shown). The central unit has access to a memory unit 2, which contains both an active and a dead memory, and can be programmed by suitable selection of the data stored therein. The signal sequences generated by the central unit 1 are fed to an interface 3, which generates suitable output signals for two driver circuits 4a, 4b, which in turn are set up to control a signal lamp 5 or a signal horn 6. The central unit 1 is programmed to allow certain states of the lamp and / or the horn to last for a respectively pseudo-randomly determined time period.

FIG. 4 shows a simplified flow diagram of the program sequence for controlling a signal with the two alternating states ON and OFF. The duration of the signal ON should each consist of a fixed time t _BE plus a variable component t _VE , while that of the signal AUS is composed of a fixed time t _BA and a variable component t _VA . The flowchart in FIG. 4 shows an in principle endless loop for alternately generating the ON and OFF signals, each of which has a duration which is randomly determined between two limit values. Of course, program branches (not shown in FIG. 4) are usually provided for the initialization and for the correct termination of the entire process as well as further auxiliary routines, but this is familiar to the person skilled in the art and need not be described further here.

Claims (10)

Method for generating a signal that draws attention to itself in the form of a sequence of different states of a signal generator, each lasting for a period of time, characterized in that the duration of at least one state is determined at least sometimes randomly or pseudo-randomly. A method according to claim 1, characterized in that said period of time is determined randomly or pseudo-randomly each time the condition occurs. Method according to claim 1 or 2, characterized in that exactly two states are generated. Method according to one of the preceding claims, characterized in that the time duration of at least one state is limited by a certain minimum value. Method according to one of the preceding claims, characterized in that the duration of at least one state is limited by a certain maximum value. Method according to one of the preceding claims, characterized in that the signal transmitter is optical. Method according to one of the preceding claims, characterized in that the signal generator is acoustic. Application of the method according to claim 1 to road or rail traffic lights, characterized in that the states of lighter and darker phases are at least one of the colors green, yellow and red. Use according to claims 3 and 8, characterized in that one of the two states is the yellow phase of a traffic light and the other state is a darker phase of the same traffic light. Use according to claim 8 or 9, characterized in that the darker phase is the deleted state.

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