Speed indicators for motor vehicle - are installed on windscreen and rear window as aid to other drivers

Patent Board

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The Netherlands

0 Attribution 0 8300073

Device for indicating a speed change of a vehicle.

Int.CI³.: 860CL1 / 54, .G08G 1/09.

Applicant: Arjeh Tal in Utrecht.

Av .: Ir. BHJ Schumann et al. Patent Office Arnold &amp; Siedsma de Ruyterlaan 2A 7511 JH Enschede.

Application no. 8300073.

Submitted January 10, 1983.

@ -0 Placed for inspection 1 August 1984.

The documents attached to this sheet are a print of the originally submitted description with claim (s) and any drawing (s).

X Sch / gn / l, Tal

-1 Short display: Device for indicating a speed change of a vehicle

The invention lies in the field of traffic safety. When assessing traffic situations and the possibility of anticipating the behavior of others, it is essential that the driver of a vehicle can at least globally orientate himself to the behavior of his fellow road users, in particular the speed and speed changes of fellow road users before and behind him.

For example, the decision as to whether or not overtaking will be made can be made depending on the estimated speed of traffic following. Once a catch-up maneuver is engaged and faster traffic is approaching behind, it is important for the drivers of both vehicles involved to know whether they have mutually noticed each other. In the present situation, for optimum safety, the front vehicle speed can increase, while the rear vehicle can reduce speed. Particularly in the evening hours, when the interpretation of the speed and behavior of others depends solely on the interpretation of the light emitted by the vehicle lighting, it is extremely difficult, if not impossible, especially during difficult situations, correct and respond in a timely manner. This means that either dangerous situations can arise or that road users behave excessively cautiously, which adversely affects the flow rate of traffic and is partly a cause of chain collisions.

To stimulate traffic safety and the flow rate of vehicle traffic, for example in the above-mentioned situation, the invention proposes to use a device for indicating a speed change of a vehicle, comprising means

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For detecting a change in speed and converting it into an output signal representative of said speed change, as well as display means responsive to said output signal, arranged at least on the front side and the rear side of the vehicle, readable from outside. If desired, the driver can also have display means.

The device of the invention offers road users the opportunity to ascertain at a glance whether a fellow road user involved in the same situation has noticed the behavior of the other person and has responded to it. This also applies to cyclists and pedestrians, for example. The present system can be referred to as a multi-interactive system. Attention is drawn to the fact that the display means 15 also respond if the accelerator pedal is released, without the brakes being applied. The operation is thus independent of intervention by the driver, such as braking, giving signals, etc.

It is advantageous if the road users are enabled to interpret the signaling provided by the display means as quickly as possible. In this connection, a distinction should preferably be made between the signaling which is issued by the display means in the case of an acceleration and which is issued in the event of a delay. To this end, the invention proposes that the display means comprise a first display unit responsive to an acceleration and a second display unit responsive to a deceleration; these two units can be combined in one unit.

It will be clear from the situation previously described for determining the idea that if the front vehicle increases its speed, a certain signal must be reproduced by the rear display means. Exactly the opposite applies to the following vehicle, of which the front display means are important in the present situation. To make the interpretation as effortless as possible, so that all road users even without thinking after a brief learning process

-3 By a single glance at the display means of a fellow road user being able to react correctly, the invention proposes that the first display unit has an optical signal of a first type on the front side and an optical signal of a second type on the rear side and the second display unit on emits an optical signal of the second type on the front side and an optical signal of the first type on the rear side.

In a practical embodiment, the display means comprise liquid crystals.

Furthermore, the display means may comprise light sources, whether or not in combination with the use of liquid crystals.

In a very practical variant, the optical signal of the first type is a red light and the optical signal of the second type is a green light. As is known, every road user interprets a red sign as a danger and a green sign with a safe situation. It is therefore not necessary here to interpret the situation thoughtfully in order to be able to respond correctly. This is particularly important in potentially dangerous situations in which the driver of the vehicle is prone to react incorrectly due to his tense or nervousness, which is not conducive to road safety.

In order not to cause the display means to jump too much in the case of small speed fluctuations occurring during normal traffic situations, it is preferred if the detection means are adapted to compare an observed speed change with a preselected reference value and only output the output signal when it is exceeded reference value. This reference value can be determined depending on the response time and the speed of the vehicle.

In a specific exemplary embodiment, the observation means are coupled via a differentiator to one for the

-4 speed of the vehicle, representative signal-issuing second detection means.

It can be advantageous if the display means are coupled to the second detection means for displaying the speed of the vehicle on the basis of the speed signal. In this case, apart from the important information about speed changes, which are directly related to the interaction between the different road users, the road user also obtains the static information, which may be important to determine whether one still has enough time to cross an intersection, for example. to pass or to perform a catch-up maneuver.

In order not to cause the speed reading by the display means to be too restless, the display means preferably comprise a memory for storing the speed signal and changing the display of the speed of the vehicle only after a speed change of at least a preselected value. In a practical embodiment, this preselected speed change amounts to 5 kilometers per hour.

The invention will now be elucidated with reference to the drawing of a few random exemplary embodiments, to which, however, the invention is not limited.

FIG. 1 is a perspective view, obliquely from the front, of an automobile with a device according to the invention;

FIG. 2 is a perspective view, obliquely from the rear of the car according to FIG. 1;

<td>FIG.</td><td>3</td><td>a</td><td>display unit</td><td>in</td><td>a</td><td>first</td><td>executive</td>

<td>example</td><td>f</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>FIG.</td><td>4</td><td>a</td><td>display unit</td><td>in</td><td>a</td><td>second</td><td>executive</td>

<td>example</td><td>• /</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>FIG.</td><td>5</td><td>a</td><td>display unit</td><td>in</td><td>a</td><td>third</td><td>executive</td>

example;

FIG. 6 is a block diagram of an embodiment of the device according to the invention; and

FIG. 7 a slightly further detailed diagram.

FIG. 1 shows an automobile 1 on the windscreen 2 of which

A first display unit 3 is provided. This display unit 3 will be discussed in more detail later.

FIG. 2 shows the same automobile 1_T on the rear window 4 of which a second display unit 5 is arranged.

The display units 3 and 5 each comprise a segment 6 for displaying speed changes and a segment 7 for displaying the speed in numerical form. The unit 3 also displays the speed value in mirror image.

FIG. 3 shows a display unit 8, with a segment 9 for displaying speed changes in the form of an upward-pointing arrow 10, which can light up green and a downward-looking arrow 11, which can light up red. This display unit 8 is intended to be mounted on the rear window of an automobile, since when the speed is reduced the red arrow 11 lights up, which means a danger indication for traffic coming behind. When increasing speed, the arrow 10 is energized, causing it to emit green light. The arrows 10 and 11 are designed as light-emitting diodes in this example.

The segment 7 represents the current speed in numerical form, on the understanding that the last digit can only be a 0 or a 5, in order to ensure that the reading is as quiet as possible.

FIG. 4 shows a variant in which the function of the arrow 10 according to FIG. 3 has been taken over by a plus sign 12 while the arrow 11 has been replaced by a minus sign 13.

FIG. 5 shows an embodiment in which a speed increase is indicated by a green lamp 14 and a speed reduction by a red lamp 15.

FIG. 6 shows a block diagram of the device according to the invention. A speed cable 16 is coupled to a transducer 17, which outputs a signal representative of the vehicle speed to an analog digital converter 18, which in turn outputs an output signal to a microprocessor 19. This microprocessor 19 outputs control signals to a windshield display unit 20 and of a car

6 a corresponding display unit 21 to be fitted to the rear window of the car. Both units 20 and 21 are of the type described with reference to FIG.

As can be seen from the diagram of Fig. 6, the microprocessor 19 outputs three output signals via outputs 22, 23, 24.

The output 22 is coupled to the segments 7 of the display units 20 and 21 for displaying the speed of the vehicle in numerical form. The output 23 is coupled to the lamp 14 of the unit 20 and the lamp 15 of the unit 21; the output 24 is coupled to the lamp 15 of the unit 20 and the lamp 14 of the unit 21. As a result of this control, as will be clear, the energization takes place such that a red indication at the front is always combined with a green indication at the rear and a green indication at the front with a red indication at the rear of the vehicle. This is advantageous, because a speed reduction for traffic following behind must give a danger indication, while the traffic ahead must be given an indication of safety and vice versa.

The microprocessor comprises a comparator for comparing an observed speed change with a pre-entered reference value, such that only an output signal is output to the segment representing the speed changes when that reference value is exceeded.

The microprocessor also comprises a memory for storing the signal representative of the speed and only after a speed change of at least 5 km / h changing the display of the speed value by the segments 7.

The analog-to-digital converter 18 can be of the 8-bit type, with which speeds of up to 256 km / hour can be processed with a resolution of 1 km / hour. In this connection, the microprocessor 19 can also be of the 8-bit type.

The microprocessor contains two parts, namely the processor itself and a PROM chip. For the processor can

-7 use is made of an INTEL 8080 or MC 6800 from Motorola. Data (digital speed from the ADC) and processing program are stored in the PROM. In addition to the reference values ​​for the speed and the change in speed, the program also includes those procedures which, after processing of the data, provide signals when the reference values ​​are exceeded to the corresponding segments.

FIG. 7 gives an implementation example in which use is made of inductive coordination. The figure shows the speed cable 16, which is designed as a bowden cable, ie a cable with a stationary sheath 25 and a steel core 26 slidable in axial direction therein. The core 26 is displaced by means not shown in accordance with the speed of the vehicle. The casing 25 has an opening 27 through which an arm 28 coupled to the core 26 extends, which arm is connected to a coil core 29 of ferromagnetic material which, depending on the displacement of the core 26, is present more or less within a coil 30. is such that the inductance of the coil 30 varies depending on the position of the coil core 29, which in turn, via the position of the core 26, depends on the speed of the vehicle.

With a capacitor 31 and an operational amplifier 32, the coil 30 forms part of an active tuned circuit. The output signal at an output 33 is a frequency signal with a frequency in the MHz region. The signal is applied to a 2ⁿdivider 34 after which it is applied to an 8-bit counter 35, which supplies its output signal to the microprocessor 19.

It will be clear that the invention is not limited to the described and drawn exemplary embodiments.

The display of the speed is not always necessary, so that, for example, a display unit can only comprise a segment which displays speed changes.

Furthermore, the optical signaling of speed changes can take place blinking, so that the attention of 8300073

-8 other road users are drawn faster.

For the display units, use can be made of incandescent lamps, optionally in combination with liquid crystals, liquid crystals responsive to striking light, or light-emitting diodes.

3 0 0-0 7 3

X Sch / gn / 1, Tal