Patent ID: 12243419

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

As explained throughout this specification, the object of the system and method for monitoring personal mobility vehicles (MVP) in urban environments is not only to detect the presence of an MVP (which we remember are those in accordance with DGT instruction 16/V-124) but also obtain all kinds of information about this vehicle, such as speed, type, direction of travel and length by means of a double coil (1) disposed under the pavement of an urban road connected to an electronic unit (2to5) configured to process the data coming from the coil.

Personal mobility vehicles, as indicated, are understood as those which are described in instruction 16/V-124 of the Spanish General Directorate of Traffic (DGT) and, in general, refer to any electric, human or mixed electric-human traction vehicle that cannot be classified as motor vehicles and are intended for use on specific or generic urban roads (for example, bike lanes), in some cases including sidewalks. Therefore, the present invention intends to exclude from its use any vehicle classified as a motor vehicle, defined as mechanical-traction vehicles with a combustion engine, hybrid engine or electric engine classified as motor vehicles (cars, large cylinder capacity motorcycles, buses or trucks, all of them with and without a trailer).

In the present invention, the double magnetic coil (1) has been geometrically modified, since in general it has maximum measurements of 0.5×0.4 metres, with a number of turns between 5 and 8, as well as an oscillation frequency between 400 kHz and 800 kHz. As the size of the coils has been reduced, same work at approximately 400 kHz in the absence of MVP, which increases by around 3% when the MVP passes the coil. However, these values are adjustable depending on the scenario and the specific application of the system.

As can be seen inFIG.1, the system that is the object of the present invention comprises a double magnetic coil (1) which in a particular, non-limiting embodiment has measurements of 48×32 centimetres with7turns in the inner and outer loops. This double magnetic coil (1) is connected to an oscillator circuit (2) implemented with a NAND logic gate.

The assembly of double magnetic coil (1) and the oscillator (2) is connected to a phase-locked loop or PLL circuit (3) designed with a Lead-Lap filter and a voltage controlled oscillator or VCO configured to provide variation in voltages as a function of the oscillation frequency of the system.

Finally, the phase-locked loop (3) is connected to a signal conditioning circuit (4) specifically implemented with an instrumentation amplifier. The conditioned signal then goes to a signal processor (5) that digitises and processes the signal by means of different algorithms, obtaining as a result the road parameters indicated above, that is, speed, typology, direction of travel and length of the vehicle.

In general, the presence of at least one personal mobility vehicle on the double magnetic coil (1) causes a decrease in the loop inductance, which in turn produces a frequency modulation, i.e., an increase in the oscillation frequency of the complete system. In the known systems of the state of the art, measurements are taken directly from the value of the oscillation frequency of the system and the characteristic magnetic imprint of each vehicle is obtained therewith. However, the system of the invention obtains the same magnetic profile by measuring the voltage, since, as previously described, the phase-locked loop (3) provides voltage levels equivalent to the frequency deviation caused by the personal mobility vehicle traffic over the double magnetic coil (1).

The signal processor (5) comprises a logic processing unit and a memory or memories that store a program or programs made up of a plurality of instructions which, when executed by the logic processing unit, cause the signal processor (5) to execute the method inFIG.2and explained in more detail below.

As can be seen inFIG.2, firstly and from the point of rest (2.1), the processor (5) detects whether or not there is a variation in voltage (2.2). If there is no variation in voltage, the processor (5) remains at rest (2.1). However, if there is a variation in voltage (2.2) the presence of a vehicle is detected (2.3) and a magnetic profile of the vehicle is obtained (2.4).

This magnetic profile is a measurement of voltage as a function of time V(t) (2.5) which allows calculating its derivative V′(t) (2.6) to calculate the maxima and minima (2.7) of the function V(t) and to establish, at least: (a) the classification and typology of the personal mobility vehicle; (b) the speed and length of the personal mobility vehicle as it passes over the coil (1); (c) the direction of travel of the personal mobility vehicle; and (d) density of vehicles in a given area.

FIG.3shows different curves of a magnetic profile of a non-limiting exemplary embodiment of a personal mobility vehicle. The curves represent two functions V(t) and V′(t) for two different speeds (the two upper curves are slower and the two lower curves are faster). These curves are the graphical representation of the magnetic fingerprint detected by the signal processor (5) and correspond to the temporal function of voltage (V(t)) and its derivative (V′(t)).

Thus, the essential parts A-B-C of a non-limiting exemplary embodiment of an electric personal mobility vehicle (specifically, an electric scooter) are indicated in each graph and which are the parts that cause the greatest variations in inductance in the double magnetic coil (1) and, therefore, to be reflected in the magnetic profiles shown in the curves ofFIG.2. These parts, referenced in this non-limiting exemplary embodiment as A-B-C are the following: (A) motor integrated in the front wheel, stator with copper windings, rotor with ferrite and aluminium casing; (B) aluminium compartment where the lithium batteries and power electronics are housed; and (C) rear wheel with aluminium rim and brake disc.

FIG.3, as indicated, represents four curves, where the first two (two upper ones) correspond to the magnetic profile generated by the personal mobility vehicle at low speed and its corresponding derivative, and the next two (two lower curves) correspond to the profile generated by the same vehicle, but at a higher speed and its corresponding derivative.

Thus, in the first place, it is observed how the first step obtained (A) corresponds to the motorised wheel. This wheel achieves a more abrupt variation in voltage than the rear wheel (point C) because the motor is located in the front wheel (A), motor which contains copper windings and more ferromagnetic material than the rear wheel (C). In addition, it can be said that the motor creates a magnetic field that causes this change to be much more pronounced.

Moreover, it is observed how (B) forms a “plateau” in voltage because it is located at the base of the personal mobility vehicle. In other words, the vehicle is completely on top of the double magnetic coil (1). Between the points (A) and (B) indicated in the graphs, the moment in which the main wheel has crossed the last segment of the coil (1) can be observed, as well as between points (B) and (C) is observed how the rear wheel enters the double magnetic coil (1). These two slopes are also different due to the different amount of ferromagnetic material present in the two wheels. This can be better appreciated at point (C) where only the rear wheel remains within the double magnetic coil (1).