Patent Description:
Nowadays, determining of the running phases of a user is a very important aspect which allows to better monitor the pace quality of a user while running in order to prevent strain on the joints, pain, injuries and accidents and, in the case of competitive running, as well as to improve performance by reducing the waste of energy, fatigue and so on.

In this regard, a running phase of a user is the so-called phase of overstride.

Indeed, the phase of overstride occurs when the beginning of the contact of a foot on the running surface occurs in a point along the running direction, ahead of the point of the running surface in which the vertical line passing through the center of gravity of the user's body falls.

If the quality of the user's running pace is good, the beginning point of the contact of the user's foot on the running surface should substantially coincide with the point of the running surface in which the vertical line passing through the center of gravity of the user's body falls and the user's pace is thus considered optimal (limited to the phase of overstride) and no substantial changes are needed to eliminate such an effect.

One way, although not the best, to determine the phase of overstride is correlated to detecting the angular inclination of the tibia of the user's front leg with respect to the vertical traceable from the center of gravity of the body, considering a horizontal running plane.

Specifically, if the phase of overstride is acceptable because it is small, the angular inclination of the tibia of the front leg substantially coincides with the vertical traceable between the center of gravity of the user's body and the horizontal running plane. Once again, the quality of the user's pace is considered optimal, limitedly to a phase of overstride, such as not to require substantial corrections.

Once again, in presence of an unacceptable phase of overstride, the set angle of the angular inclination of the front leg with respect to the vertical traceable between the center of gravity of the body and the horizontal plane may be not null or may be in all cases greater than a set threshold value.

So, the quality of the user's pace is deemed not optimal (at least limitedly to the phase of overstride) and running corrections are consequently needed to eliminate or at least reduce as much as possible the phase of overstride, whereby preventing strain on joints, pain, injuries, accidents and possibly improve the athletic performance in the case of competitive running.

According to a solution of the prior art, a method for determining running phases of a user, among which is the phase of overstride, includes using an electronic device, e.g. an inertial measurement unit (IMU), which can be worn by the user, e.g. applied on the tibia of a leg, adapted to detect various inertial parameters representative of the motion of the leg, such as, for example, an angle of inclination with respect to the horizontal plane, rotational velocity, acceleration and so on.

The parameters detected by the inertial measurement unit are employed by a microprocessor (of the electronic device applied on the leg or a further electronic device worn by the user even on another part of the body, e.g. at the waist) to determine the contact of the foot on the running plane, and so the amplitude of the phase of overstride in order to indicate need to correct the pace or not to the user.

This method for determining the phase of overstride is not free from defects.

Firstly, this method requires the use of one or more electronic devices that the user must wear while running.

Such one or more electronic devices, in addition to causing annoyance to the user while running, are subject to movements or impacts which could imply, on one hand, the imperfect detection of measurable inertial parameters and, on the other hand, the displacement or even the accidental falling from the leg or part of the body onto which the electronic devices are applied.

Furthermore, multiple electronic devices with inertial measurement units, e.g. one for each leg or even one on each calf and on each thigh, hip, and so forth, could be provided in order to improve measurement accuracy or completeness.

However, it is apparent that increasing the number of electronic devices which can be worn by the user causes a considerable increase of the annoyance for the user who, on the contrary, wants to be as free as possible while running.

Furthermore, the detection of one or more inertial parameters representative of the leg, such as the inclination angle of the tibia, are in all cases indirect measurements from which to determine the phase of overstride which make the evaluation somewhat imprecise and not very significant despite successive processing.

XP032319033 discloses a method for determining the running phases of a user on a treadmill driven by an electric motor and comprising a data processing unit operatively connected to the electric motor, the data processing unit being configured to control said electric motor, determine variations of motor current values over time, determine respective time instants of at least two points being representative of the instants of the interaction of the user with the physical exercise surface of the treadmill during the run, and determine at least one running phase of the user on the physical exercise surface of the treadmill as a function of the respective time instants.

It is the object of the present invention to devise and provide a method for determining running phases of a user on a treadmill which allows to solve, at least partially, the drawbacks mentioned above with reference to the prior art, which is the less invasive as possible for the user and which guarantees high accuracy and promptness of the obtainable results.

Such an object is achieved by a method according to claim <NUM>.

It is an object of the present invention also a treadmill implementing such method according to claim <NUM>.

Further features and advantages of the method and treadmill according to the invention will become apparent from the following description which discloses preferred embodiments, given by way of indicative, non-limiting examples, with reference to the accompanying drawings, in which:.

It is worth noting that equivalent or similar elements are indicated by the same numerical and/or alphanumerical reference in the aforesaid drawings.

Reference numeral <NUM> indicates a treadmill as a whole.

It is worth noting that <FIG> and <FIG> show some embodiments of the treadmill <NUM> and of some components simply by means of a block chart in order to highlight the technical features which are essential and important for better understanding the present invention.

With particular reference to the embodiment shown in <FIG> and to the embodiment shown in <FIG>, the treadmill <NUM> comprises a base <NUM> extending along a longitudinal axis L, indicated by a dashed line in the figure.

The base <NUM> comprises a first rotating element <NUM> and a second rotating element <NUM> adapted to rotate about respective rotational axes, a first rotational axis A2 for the first rotating element <NUM> and a second rotational axis A3 for the second rotating element <NUM>, transversal to the longitudinal axis L of the base <NUM> of the treadmill <NUM>.

It is worth noting that the first rotating element <NUM> is arranged at an end of the base <NUM>, whilst the second rotating element <NUM> is arranged at a second end of the base <NUM>, opposite to said first end along the longitudinal axis L of the base <NUM>.

The base <NUM> further comprises a physical exercise surface <NUM> operatively connected to the first rotating element <NUM> and to the second rotating element <NUM>.

It is worth noting that the physical exercise surface <NUM>, between the first rotating element <NUM> and the second rotating element <NUM>, has a side profile which is substantially parallel with respect to the longitudinal axis L of the base <NUM>.

For the purposes of the present description, "physical exercise surface" means the rotational surface of the treadmill <NUM> on which a user U (diagrammatically shown in <FIG> and <FIG>), by placing his or her feet or lower limbs in general, can carry out a physical exercise, such as, for example, running, and also pushing exercises, or any other type of physical exercise that the treadmill <NUM> allows.

Running is the physical exercise to which reference will be made in particular for the purposes of the present invention.

Furthermore, it is worth noting that "rotating element" means any mechanical element adapted to rotate about a respective rotational axis so as to impart a rotation to the "physical exercise surface" operatively associated with one or more of these rotating elements.

The type of rotating elements, some examples of which will be described below, depends on the type of physical exercise surface to be rotated.

In greater detail, the rotation of the first rotating element <NUM> also drives the physical exercise surface <NUM> and the second rotating element <NUM> into rotation. In an entirely similar manner, the rotation of the second rotating element <NUM> drives the first rotating element <NUM> and the physical exercise surface <NUM> into rotation.

In an embodiment (not shown in the figure), the physical exercise surface <NUM> comprises a belt wound about the first rotating element <NUM> and the second rotating element <NUM> and a supporting table, arranged between the first rotating element <NUM> and the second rotating element along the longitudinal axis L of the base <NUM>, on which the belt defining the physical exercise surface <NUM> runs.

In this embodiment, the first rotating element <NUM> and the second rotating element <NUM> comprise two respective rolls, each rotationally coupled to the base <NUM> of the treadmill <NUM> at the two ends of the base <NUM>, to which the belt is connected.

According to a further embodiment, the physical exercise surface <NUM> comprises a plurality of slats transversal to the longitudinal axis L of the base <NUM>, conferring a slat-like conformation to the physical exercise surface <NUM>.

In this embodiment, both the first rotating element <NUM> and the second rotating element <NUM> comprise two respective pulleys arranged near the side portions of the base <NUM>, transversely to the longitudinal axis L of the base <NUM>, adapted to support the plurality of slats at the side edges of each slat.

Furthermore, the physical exercise surface <NUM>, at the side edges of the plurality of slats, is supported by respective side guides (also not shown) fixed to the base <NUM>, each comprising a series of small rolls freely coupled to the base <NUM> on which the respective side edge of the plurality of slats runs.

It is worth noting that, according to alternative embodiments, in combination with the preceding one, the physical exercise surface <NUM>, comprising the plurality of slats transverse to the longitudinal axis L of the base <NUM>, may have a plane (parallel) side profile or a curved side profile, with respect to a reference plane, e.g. a supporting surface of the treadmill <NUM>.

With reference again to the embodiment in <FIG> and to the embodiment in <FIG>, the treadmill <NUM> further comprises an electric motor <NUM> operatively associated with at least either said first rotating element <NUM> or second rotating element <NUM>.

Examples of motors may be electric brushless type motors, three-phase asynchronous electrical motors, variable reluctance electrical motors, direct current electrical motors, and so on.

It is worth noting that in the description which follows and in <FIG> and <FIG>, for convenience, the case in which the electric motor <NUM> is associated with the first rotating element <NUM> is considered, since the electric motor <NUM> could be associated with the second rotating element <NUM> in an equivalent and alternative manner.

The electric motor <NUM>, operatively associated with and controllable by a data processing unit (described below), is configured to rotate the first rotating element <NUM> about the respective rotational axis, the first rotational axis A2. The rotation of the first rotating element <NUM> drives the physical exercise surface <NUM> into rotation, which rotates the second rotating element <NUM> in turn.

When the physical exercise surface <NUM> is moving, the forward direction of the physical exercise surface <NUM>, indicated by reference S1 in <FIG> and <FIG>, is opposite to the forward direction of the user U, indicated in <FIG> and <FIG> by reference S2.

The treadmill <NUM> further comprises a drive <NUM>' operatively connected to the electric motor <NUM>.

The drive <NUM>' is configured to supply an electric current to the electric motor <NUM> to generate a torque adapted to move the physical exercise surface <NUM> so that the electric motor <NUM> and drive <NUM>' assembly can correct the instantaneous rotation speed of the electric motor <NUM>, which is inevitably disrupted by the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity, returning it as close as possible to a reference instantaneous speed rotation value.

The treadmill <NUM> further comprises a data processing unit <NUM> operatively connected to the electric motor <NUM>.

The treadmill <NUM> further comprises a memory unit <NUM>, operatively connected to the data processing unit <NUM>.

The memory unit <NUM> can be either internal or external (as shown in the <FIG> and <FIG>, for example) to the data processing unit <NUM>.

It is worth noting that the memory unit <NUM> is configured to store one or more program codes which can be executed by the data processing unit <NUM> and data generated by said one or more program codes.

The data processing unit <NUM> is configured to execute a method for determining running phases of a user U on a treadmill <NUM> in accordance with the present invention, described below.

It is worth noting that the running phases of a user on a treadmill comprise a phase of flight of different feet, a phase of overstride, a phase of propulsion, a phase of contact, a phase of flight of the same foot (also defined and described in detail below).

In accordance with an embodiment (shown in <FIG> and <FIG>), the data processing unit <NUM> comprises a first data processing block <NUM>, e.g. a microprocessor or a microcontroller, operatively connected to the electric motor <NUM>.

It is worth noting that in this embodiment, the first data processing block <NUM> may coincide with the microprocessor of the drive <NUM>' of the electric motor <NUM>.

In this embodiment, the memory unit comprises a first memory block <NUM> operatively connected to the first data processing block <NUM>.

In this embodiment, all the steps of the method for determining running phases of a user U on a treadmill <NUM> in accordance with the present invention, described below, are executed by the first data processing block <NUM>, e.g. by the microcontroller of the drive <NUM>' of the electric motor <NUM>.

In accordance with a further embodiment, in combination with the preceding one (shown by dashed lines in <FIG> and <FIG>), the data processing unit <NUM> further comprises a second data processing block <NUM>, e.g. a microprocessor or a microcontroller, operatively connected to the first data processing block <NUM>.

The second data processing block <NUM> is remote with respect to the first data processing block <NUM>.

For example, the second data processing block <NUM> may be positioned in a control electronics of the display or user interface of the treadmill <NUM>.

In this embodiment, the memory unit comprises a second memory block <NUM> operatively connected to the second data processing block <NUM>, also positioned in the control electronics of the display or user interface of the treadmill <NUM>.

The data link between the first data processing block <NUM> and the second data processing block <NUM> may be wired or wireless (e.g. by means of Bluetooth, NFC or Wi-Fi type data communication channel).

In an embodiment, all the steps of the method for determining running phases of a user U on a treadmill <NUM> in accordance with the present invention, described below, are performed exclusively by the first data processing block <NUM>, e.g. by the microcontroller of the drive <NUM>' of the electric motor <NUM>.

In a further embodiment, alternative to the preceding one, a first plurality of steps of the method for determining running phases of a user U on a treadmill <NUM> in accordance with the present invention are performed by the first data processing block <NUM> (e.g. by the microcontroller of the drive <NUM>' of the electric motor <NUM>), whilst a second plurality of steps, subsequent to the first plurality of steps, of the same method may be performed by the second data processing block <NUM>, on the basis of the data processed and received from the first data processing block <NUM>.

So, it is advantageously possible to reduce the task, from a computational point of view, of the first processing block <NUM> which, corresponding for example to the microcontroller of the drive of the treadmill <NUM>, is configured to supply the electric current to the electric motor <NUM> to generate the torque adapted to move the physical exercise surface <NUM> so that the electric motor <NUM> and drive <NUM>' assembly can correct the instantaneous rotation speed of the electric motor <NUM>, inevitably disrupted by the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity, returning it as close as possible to an instantaneous speed rotation reference value.

In accordance with a further embodiment, in combination with any one of those described above, shown in <FIG>, <FIG>, the treadmill <NUM> also comprises a frame <NUM> extending substantially in a vertical direction with respect to the base <NUM>.

The frame <NUM> is a combination of uprights and tubular elements operatively connected to one another and distributed so as to define a supporting structure which at least in part surrounds the user U when he or she is on the physical exercise surface <NUM> (as shown in <FIG>).

In accordance with a further embodiment, which is not part of the invention, either in combination with or alternatively to any of those described above, shown for example in <FIG>, <FIG>, the treadmill <NUM> comprises at least one distance sensor <NUM>, e.g. an infrared sensor, operatively connected to the data processing unit <NUM> (not shown in <FIG>, <FIG>).

The at least one distance sensor <NUM> is configured to detect a variation in the position of a portion (e.g. around the knee) of a set leg of the user U (right or left) with respect to a reference position, while performing the physical activity on the treadmill <NUM>.

As shown in <FIG>, <FIG>, the at least one distance sensor <NUM> is for example fixed to the front part of the frame <NUM> of the treadmill <NUM> and is inclined at a predetermined angle, e.g. <NUM>°, so that the emitted detection beam (indicated by reference F) strikes the user U and is reflected towards the detection region of said at least one distance sensor <NUM>.

In greater detail, the at least one distance sensor <NUM> is preferably arranged on a side of the treadmill <NUM> so as to detect the variation of the position of a portion of a set leg of the user U with respect to a reference position (represented by said at least one distance sensor <NUM>).

As shown by way of example in <FIG>, <FIG>, the at least one distance sensor <NUM> is on the right side and is configured to detect the variation of the position of the portion around the knee of the right leg of the user U.

<FIG> show the user in the moment of the end of the phase of contact of the left foot with the physical exercise surface <NUM> ("toe off" of the left foot) which is followed by the beginning of the phase of flight of the left foot, in which there is no contact with the physical exercise surface <NUM> of the treadmill <NUM>. The phase of flight ends with the beginning of the phase of contact of the right foot with the physical exercise surface <NUM> of the treadmill <NUM> ("heel strike" of the right foot).

In this case, in the interval of time preceding the beginning of the phase of contact of the right foot with the physical exercise surface <NUM> of the treadmill <NUM>, the at least one distance sensor <NUM> is adapted to detect a decrease over time of the distance of the portion of the right leg.

As described below, the variation of the position of a portion of a set leg of the user U may be employed by the data processing unit <NUM> while executing the method for determining running phases of a user on a treadmill according to the present embodiment which is not part of the invention, in which a determined running phase may be indeed associated with a change of position of a portion of a set leg of the user.

By way of example, again with reference to the example in <FIG>, <FIG>, the data processing unit <NUM> is configured for example to associate the beginning of the phase of contact with the physical exercise surface <NUM> of the treadmill <NUM> with the right foot, on the basis of the position detected by the at least one distance sensor <NUM>.

In an embodiment which is not part of the invention, in combination with or alternatively to the preceding one, said at least one distance sensor <NUM> may be configured to detect the position variation of a portion of both the legs of the user U with respect to a respective reference position (e.g. represented by said at least one distance sensor <NUM>).

In a further embodiment, alternative to those described above, the treadmill <NUM> may comprise at least one pair of distance sensors of the type described above, one arranged on the right side of the treadmill <NUM> and one arranged on the left side of the treadmill <NUM>.

Turning back now in general to the treadmill <NUM>, it is worth noting that, in greater detail, the data processing unit <NUM> is advantageously configured to determine a magnitude variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity, such as running.

Indeed, the Applicant has monitored in a synchronized manner a video recording of a plurality of sample users running on the treadmill <NUM> and the aforesaid magnitude variable over time, according to various embodiments, noting a correlation between the trend over time of such a magnitude variable over time and the running on the treadmill <NUM> of the plurality of sample users, thus with the interaction of a user U with the physical exercise surface <NUM> while running.

The Applicant also observes that the interaction of the user U with the physical exercise surface <NUM> can be subdivided into the running phases of the user U on the physical exercise surface <NUM> of the treadmill <NUM>, such as a phase of flight between different feet, a phase of overstride, a phase of propulsion, a phase of contact by the same foot, a phase of flight of the same foot.

So, the magnitude variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity, which can be determined by the data processing unit <NUM>, is also correlated to the running phases of the user U on the physical exercise surface <NUM> of the treadmill <NUM>.

As previously mentioned, the running phases include:.

Turning back to the magnitude variable over time, it will be described in greater detail below in the description of the method according to the present invention with particular reference also to <FIG>.

In an embodiment of the treadmill <NUM>, e.g. shown in <FIG>, this magnitude variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is a first absorption electric current of the electric motor <NUM>, indicated by reference I1 in <FIG>.

In greater detail, as clearly shown in <FIG>, the first absorption electric current I1 of the electric motor <NUM> is an envelope of an operating electric current I1' of the electric motor (e.g. the motor phase current), having a respective frequency modulation.

In this embodiment (<FIG>), which is not part of the invention, the first absorption electric current I1 of the electric motor <NUM> is detected by the data processing unit <NUM>.

Indeed, the data processing unit <NUM>, during the normal operation of the treadmill <NUM>, generates electric voltage and electric current on the motor <NUM> to control it, so that the data processing unit <NUM> can know its values directly.

In this regard, the treadmill <NUM> may comprise a respective detection unit of the first absorption electric current I1 of the electric motor <NUM> (not shown in the figures), operatively connected to the electric motor <NUM> and operatively associated with the data processing unit <NUM>.

For example, this measurement unit is one or more electric current sensors.

In an embodiment shown, the detection unit is integrated in the data processing unit <NUM>.

In a further embodiment, alternative to the preceding one, the detection unit is external to the data processing unit <NUM>.

In this embodiment, the treadmill <NUM> comprises a first data communication module (not shown in the figures) operatively associated with the data processing module <NUM> and a second data commutation module (also not shown in the figures) operatively connected to the detection unit, both configured to communicate with one another by means of a data communication channel of the wireless type (e.g. a Bluetooth, NFC or Wi-Fi type data communication channel) or by means of a data connection channel of the wired type.

According to a further embodiment, shown in <FIG>, either in combination with or alternatively to the preceding one, the magnitude variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the first absorption electric current I1 of the electric motor <NUM>.

In this embodiment, the electric motor <NUM> is preferably a three-phase motor supplied by a triad of supply currents.

In this embodiment, the treadmill <NUM> comprises at least one speed sensor <NUM> operatively connected to the electric motor <NUM> and to the data processing unit <NUM>.

The at least one speed sensor <NUM> is adapted to detect the rotation speed of the electric motor <NUM> which can be used by the data processing unit <NUM>, as described below, to determine the first absorption electric current I1 of the electric motor <NUM> as a function of the variation over time of the speed detected by at least one speed sensor <NUM> and by the triad of supply currents of the electric motor <NUM> of three-phase type.

For example, the at least one speed sensor <NUM> is an encoder seated onto the drive shaft of the electric motor <NUM>.

The encoder, e.g. of the optical or magnetic or other technical equivalent type, is adapted to detect the angular speed of the electric motor <NUM> which is correlated with the angular speed of said at least one first rotating element <NUM> and at least one second rotating element <NUM> to which the physical exercise surface <NUM> is connected. The angular speed of said at least a first rotating element <NUM> and at least one second rotating element <NUM> is correlated with the linear displacement speed of the physical exercise surface <NUM>.

In this embodiment, the electric motor <NUM> of three-phase type can be compared, from a mathematical point of view, by means of mathematical transforms (intrinsically known), to an electric motor model of the two-phase type having two electric current components, in which the first component (usually indicated by Id) is adapted to generate the flow of electric current, while the second component (usually indicated with Iq) is adapted to generate the torque. The second electric current component corresponds to the first absorption electric current I1 of the electric motor <NUM>.

It is also worth noting that in addition to the encoder, other examples of speed sensors may be any sensor adapted to detect a magnitude of the processing from which it is possible to determine the angular speed, such as an accelerometer, a gyroscope, a combination of these or other equivalent technical and so on.

In a further embodiment, also shown in <FIG>, alternatively to the preceding ones, the magnitude variable over time correlated with the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the instantaneous rotation speed of the electric motor <NUM>, indicated by reference VR in <FIG>.

Examples of said at least one speed sensor <NUM> were previously provided with reference to the preceding embodiment of the treadmill <NUM>.

In this embodiment, the magnitude variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is directly the instantaneous rotation speed VR of the electric motor <NUM> detected by at least one speed sensor <NUM>, as will be explained below in detail.

With reference now also to <FIG>, a method for determining running phases of user U on a treadmill <NUM>, hereinafter also simply method, will now be described according to different embodiments.

Firstly, with reference in particular to <FIG> and <FIG>, the Applicant observes that the interaction of the user U with the physical exercise surface <NUM> of the treadmill <NUM> can be represented by a magnitude GR detectable on the treadmill <NUM>, the variation of which over time is precisely correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity.

As mentioned above, the Applicant has monitored in a synchronized manner a video recording the running pace on the treadmill <NUM> of a plurality of sample users and the aforesaid magnitude variable over time, according to different embodiments, noting a correlation between the trend over time of such a magnitude variable over time and the running pace on the treadmill of the plurality of sample users, thus the interaction of a user U with the physical exercise surface <NUM> while running.

In particular, it is worth reasserting that the interaction of the user U with the physical exercise surface <NUM> can be subdivided into the running phases of the user U on the physical exercise surface <NUM> of the treadmill <NUM>.

The running phases comprise a phase of flight between two different feet, a phase of overstride, a phase of propulsion, a phase of contact by the same foot, a phase of flight of the same foot (as defined above).

In more detail, it is worth noting that the Applicant has observed a set correspondence between the running phases into which the interaction of a user U with the physical exercise surface <NUM> can be subdivided while performing the physical activity (running) and a plurality of points (which can be defined as characteristic) of the trend over time of such a magnitude variable over time.

In greater detail, the magnitude GR variable over time has a substantially periodic trend.

In this regard, the Applicant observes that on the periodic trend of such a magnitude GR variable over time it is possible to identify a set time instant of each point of said plurality of points, from the processing of which running phases of the user U on the treadmill <NUM> can be obtained. It is worth noting that in the respective time instant, each point of the plurality of points has a set value.

The running phases into which the interaction of a user U with the physical exercise surface <NUM> can be subdivided while performing the physical activity and the plurality of (characteristic) points of the trend over time of such a magnitude variable over time will be described below.

With general reference to both <FIG> and <FIG>, the plurality of points of the periodic trend of the magnitude GR variable over time comprises a first point HS in a first time instant t1. The first point HS has a first value GR1 in the first time instant t1.

The first point HS is representative of an interaction of a portion of a foot of the user U with the physical exercise surface <NUM>, at the beginning of the interaction of the foot of the user U with the physical exercise surface <NUM>.

In other words, the first time instant t1 of the first point HS (Heel Strike) is representative of the instant of impact on the physical exercise surface <NUM> of a portion of the foot, such as the first contact between the foot and the physical exercise surface <NUM>.

Such an impact (incorrectly) occurs with the heel of the foot in case of unacceptable overstride in the pace of the user U, and it (correctly) occurs with the forefoot (slightly supine) if the acceptable overstride in the pace of the user U is acceptable.

The plurality of points of the periodic trend of the magnitude GR variable over time also comprises a second point MS in a second time instant t2 representative of an interaction of a foot of the user U with the physical exercise surface <NUM> in which the vertical line passing through the center of gravity of the body of the user U intersects a contact portion of the foot with the physical exercise surface <NUM>. The second point MS has a second value GR2 in the second time instant t2.

It is worth noting that such a contact portion of the foot with the physical exercise surface <NUM> is typically the forefoot.

It is worth noting that the interaction of the contact portion of the foot with the physical exercise surface <NUM> allows the user U to apply the maximum pressure on the physical exercise surface <NUM>.

In other words, the foot can apply the maximum pressure on the physical exercise surface <NUM>, whereby starting the phase of propulsion.

Indeed, the second time instant t2 of the second point MS (mid stance) represents the instant of median resting of the foot, i.e. the phase in which the foot is under the vertical line passing through the center of gravity of the body of the user U.

In this case, the forefoot completely rests on the physical exercise surface <NUM> and the center of gravity of the body of the user U is located closest to the physical exercise surface during its vertical oscillation.

The plurality of points of the periodic trend of the magnitude GR variable over time also comprises a third point TO in a third time instant t3. The third point TO has a third value GR3 in the third time instant t3.

It is worth noting that the first value GR1 of the first point HS is comprised between the third value GR3 of the third point TO and the second value GR2 of second point MS.

The third time instant t3 of the third point TO is representative of the instant of interaction of a portion of a foot of the user U on the physical exercise surface <NUM>, before the foot is off the physical exercise surface <NUM> (beginning of phase of flight of the foot or beginning of the phase of flight between two different feet).

In other words, in the third point TO, the foot applies the minimum pressure on the physical exercise surface <NUM> before starting the phase of flight.

It is worth noting that the third point TO (toe off) represents the end of the phase of contact of the foot (and thus the end of the phase of propulsion) and the beginning of the phase of flight of the foot.

It is worth noting that the plurality of points of the periodic trend over time of the magnitude GR variable over time comprises in succession a first point HS, a second point MS and a third point TO for one foot, a first point HS, a second point MS and a third point TO for a successive foot and so on.

In other words, the first point HS, the second point MS and the third point TO recur periodically over time, referring alternatively firstly to one foot (e.g. the right foot), then to the other (e.g. the left foot).

So, the mutually consecutive two first points HS, two second points MS or two third points TO relate to one foot and to the other, respectively.

By way of example, the following points are shown in the chart in <FIG>:.

It is also worth noting that <FIG> and <FIG> for simplicity of description, as will be explained below, show the first point HS of one foot (in a first time instant t1), the second point MS (in a second time instant t2) of the same foot, the third point TO of the same foot (in a third time instant t3) but also the third point TO of the preceding foot (in a further time instant t6).

So, as shown in <FIG> and <FIG>, the first instant t1 of the first point HS is comprised between the further time instant t6 of the third point TO and the second time instant t2 of the second point MS.

Turning back in general to the present invention, it is worth noting that the essential components of the interaction of a user U with the physical exercise surface <NUM> are:.

With reference again to <FIG>, the running phases of a user U on the physical exercise surface <NUM>, defined above, can thus be identified:.

Relatively to the phase of overstride, it is worth noting that if the respective time distance is under a set threshold value, the overstride is considered acceptable, whilst if the respective time distance is over the set threshold value, the overstride is considered unacceptable.

With particular reference to <FIG>, the magnitude GR detectable on the treadmill <NUM> the variation over time of which is correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the first absorption electric current I1 of the electric motor <NUM>.

The first absorption electric current I1 of the electric motor <NUM>, supplied by the drive <NUM>', is proportional to the torque required by the electric motor <NUM> to maintain the instantaneous rotation speed equal to a reference rotation speed value (speed set for the physical activity on the treadmill <NUM>).

The methods for determining the first absorption electric current I1 of the electric motor <NUM> will be described below when describing of the method according to the present invention.

As shown in <FIG>, the first absorption electric current I1 of the electric motor <NUM> has a substantially periodic trend over time.

The periodic trend of the first absorption electric current I1 of the electric motor <NUM> comprises a first point HS in a first time instant t1. The first point HS has a first value IV1.

The first time instant t1 of the first point HS is representative of the instant of interaction of a portion of a foot of the user U with the physical exercise surface <NUM>, at the beginning of the interaction of the foot of the user U with the physical exercise surface <NUM> (beginning of the phase of overstride, beginning of the phase of contact by the same foot).

In greater detail, the first point HS represents the inflection point of the periodic trend over time of the first absorption electric current I1 of the electric motor <NUM> between its minimum value (third point TO, defined below) and its maximum value (second point MS, also defined below).

The methods for determining the first point HS (inflection point) of the first absorption electric current I1 of the electric motor <NUM> will be described below when describing a method which is not part of the present invention.

Further considerations on the first point HS, the second point MS and the third point TO (characteristic points) of the first absorption electric current I1 of the electric motor <NUM>, were described above with reference to the magnitude GR variable over time and therefore will not repeated here.

Turning back to <FIG>, the periodic trend of the first absorption electric current I1 of the electric motor <NUM> further comprises a second point MS in a second time instant t2 successive to the first time instant t1.

The second time instant t2 of the second point MS is representative of the instant of interaction of the foot of the user U with the physical exercise surface <NUM>, in which the vertical passing through the center of gravity of the body of the user U intersects a contact portion of the foot (forefoot) with the physical exercise surface <NUM> (end of the phase of overstride, beginning of the phase of propulsion). The second point MS has a second value IV2.

It is worth reasserting that the interaction of the contact portion of the foot with the physical exercise surface <NUM> allows the user U to apply maximum pressure on the physical exercise surface <NUM>.

With reference again to <FIG>, the periodic trend of the first absorption electric current I1 of the electric motor <NUM> comprises a further third point TO in a further time instant t6. The further third point TO has a third value IV3.

The first value IV1 of first point HS is comprised between the third value IV3 of the third point TO and the second value IV2 of second point MS.

The first time instant t1 is instead between the further time instant t6 and the second time instant t2.

The further time instant t6 of the third point TO is representative of the instant of interaction of a portion of a foot of the user U on the physical exercise surface <NUM>, before such a foot is off the physical exercise surface <NUM> (beginning of phase of flight between two different feet, beginning of the phase of flight of the same foot).

In other words, in the further third point TO, the foot applies the minimum pressure on the physical exercise surface <NUM> before starting the phase of flight.

So, the phase of flight tv1 (<FIG>) between two different feet occurs between a time instant in which the preceding foot end applying pressure on the physical exercise surface <NUM> and a time instant in which the other foot begins to apply pressure on the physical exercise surface <NUM>.

Moreover, the phase of flight tv2 (<FIG>) of the same foot occurs between a time instant in which the foot end applying pressure on the physical exercise surface <NUM> and a time instant in which the foot begins to apply pressure on the physical exercise surface <NUM>.

Turning back to <FIG>, the second value IV2 in the second time instant t2 of the first absorption electric current I1 of the electric motor <NUM> is the maximum value.

Indeed, in the moment in which the pressure applied by the foot on the physical exercise surface <NUM> is maximum (i.e. before the beginning of the phase of propulsion of the foot), thus in the presence of a significant disturbance due to the interaction of the user U with the physical exercise surface <NUM>, the first absorption electric current I1 of the electric motor <NUM> absorbed by the electric motor <NUM> is maximum.

As apparent from <FIG>, the third value IV3 in the further time instant t3 of the first absorption electric current I1 of the electric motor <NUM> is the minimum value, instead.

Indeed, in the moment in which the pressure applied by the preceding foot on the physical exercise surface <NUM> is minimum (just before the preceding foot is off physical exercise surface <NUM>, i.e. before the beginning of the phase of flight between the preceding foot and the other foot or the beginning of the phase of flight of the same preceding foot), thus in absence of a significant disturbance due to the interaction of the user U with the physical exercise surface <NUM>, the first absorption electric current I1 of the electric motor <NUM> absorbed by the electric motor <NUM> is minimum.

With reference again to <FIG>, as mentioned above, the first point HS represents the inflection point of the periodic trend over time of the first absorption electric current I1 of the electric motor <NUM> between its minimum value (further third point TO) and its maximum value (second point MS).

It is worth noting that <FIG> may be used to illustrate an example of trend of the variable magnitude over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity if it is the first absorption electric current I1 of the electric motor <NUM> determined as a function of the time trend of the speed detected by at least one speed sensor <NUM> and by the triad of supply currents of the electric motor <NUM> of the three-phase type, as described previously.

With particular reference to <FIG>, the magnitude GR detectable on the treadmill <NUM>, the variation over time of which is correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity, is the instantaneous rotation speed VR of the electric motor <NUM>.

Indeed, the Applicant has noted the correction performed by the electric motor <NUM> and drive <NUM>' assembly on the instantaneous rotation speed VR of the electric motor <NUM> in order to take it back as close as possible to a reference instantaneous rotation speed value, noting the periodic trend over time of the instantaneous rotation speed VR of the electric motor <NUM> from which it is possible to determine the characteristic points of interest, such as those defined above with general reference to both <FIG> and <FIG>.

The methods for determining the instantaneous rotation speed VR of the electric motor <NUM> will be described below when describing the method according to the present invention.

As shown in <FIG>, the instantaneous rotation speed VR of the electric motor <NUM> has a substantially periodic trend over time.

The periodic trend over time of the instantaneous rotation speed VR of the electric motor <NUM> comprises a first point HS in a first time instant t1. The first point HS has a first value VR1.

In greater detail, the first point HS represents the inflection point of the periodic trend over time of the instantaneous rotation speed VR of the electric motor <NUM> between its maximum value (further third point TO, defined below) and its minimum value (second point MS, defined below).

Furthermore, the Applicant has observed that the first point HS represents the instantaneous decrease point of the periodic trend over time of the instantaneous rotation speed VR of the electric motor <NUM> between its maximum value (further third point TO, defined below) and its minimum value (second point MS) with respect to a reference instantaneous rotation speed value VG.

The methods for determining the first point HS of the instantaneous rotation speed VR of the electric motor <NUM> will be described below when describing the method according to the present invention.

Turning back to <FIG>, the periodic trend of the instantaneous rotation speed VR of the electric motor <NUM> further comprises a second point MS in a second time instant t2 successive to the first time instant t1. The second point MS has a second value VR2.

The second time instant t2 of the second point MS is representative of the instant of interaction of the foot of the user U with the physical exercise surface <NUM>, in which the vertical passing through the center of gravity of the body of the user U intersects with contact portion of the foot with the physical exercise surface <NUM> (end of the phase of overstride, beginning of the phase of propulsion).

It is worth noting that the interaction of the contact portion of the foot with the physical exercise surface <NUM> allows the user U to apply maximum pressure on the physical exercise surface <NUM>.

In other words, the foot, in the second point MS, can apply maximum pressure on the physical exercise surface <NUM>, whereby starting the phase of propulsion.

With reference again to <FIG>, the periodic trend over time of the instantaneous rotation speed VR of the electric motor <NUM> comprises a further third point TO in a further time instant t6. The third point TO has a third value VR3.

It is worth noting that the first value VR1 of first point HS is comprised between the further third value VR3 of the further third point TO and the second value VR2 of second point MS.

The first time instant t1 is between the further time instant t6 and the second time instant t2.

The further third time instant t6 of the further third point TO is representative of the instant of interaction of a portion of a foot of the user U on the physical exercise surface <NUM>, before the preceding foot is off the physical exercise surface <NUM> (beginning of phase of flight between two different feet, beginning of the phase of flight of the same foot, e.g. of the preceding foot).

In other words, in the further third point TO, the preceding foot applies the minimum pressure on the physical exercise surface <NUM> before starting the phase of flight.

As apparent from <FIG>, the second value VR2 in the second time instant t2 of the instantaneous rotation speed VR of the electric motor <NUM> is the minimum value.

Indeed, in the moment in which the pressure applied by the foot on the physical exercise surface <NUM> is maximum (i.e. before the beginning of the phase of propulsion of the foot), thus in the presence of a significant disturbance due to the interaction of the user U with the physical exercise surface <NUM>, the instantaneous rotation speed VR of the electric motor <NUM> is minimum.

In other words, the physical exercise surface <NUM> undergoes a deceleration due to the interaction of the user U with it.

As apparent again from <FIG>, the third value VR3 in the further third time instant t6 of the instantaneous rotation speed VR of the electric motor <NUM> is the maximum value.

Indeed, in the moment in which the pressure applied by the preceding foot on the physical exercise surface <NUM> is minimum (just before the preceding foot is off the physical exercise surface <NUM>, i.e. before the phase of flight between the preceding foot and the other foot or before the phase of flight of the same preceding foot), thus in absence of a significant disturbance due to the interaction of the user U with the physical exercise surface <NUM>, the instantaneous rotation speed VR of the electric motor <NUM> is maximum, because the physical exercise surface <NUM> is subject to the acceleration due to the interaction of the user U (by means of the preceding foot) with the physical exercise surface <NUM>.

In other words, the physical exercise surface <NUM> does not undergo any deceleration due to the interaction of the user U with it.

Further considerations on the first point HS, the second point MS and the further third point TO were described above with reference to the magnitude GR variable over time and therefore will not repeated here.

With reference now also to <FIG>, a method <NUM> for determining the running phases of user U on a treadmill <NUM>, hereinafter also simply method, will now be described according to an embodiment according to the present invention.

As mentioned above, the treadmill <NUM> comprises a base <NUM> extending along a longitudinal axis L.

The base <NUM> comprises a first rotating element <NUM> and a second rotating element <NUM> adapted to rotate about respective rotational axes A2, A3 transverse to the longitudinal axis L of the base <NUM>.

The base <NUM> comprises a physical exercise surface <NUM> operatively connected to the first rotating element <NUM> and to the second rotating element <NUM>.

The treadmill <NUM> further comprises an electric motor <NUM> operatively associated with at least said either first rotating element <NUM> or second rotating element <NUM>. The electric motor <NUM> is configured to rotate the at least one first rotating element <NUM> and the at least one second rotating element <NUM> by driving also the physical exercise surface <NUM> into rotation.

The treadmill <NUM> further comprises a data processing unit <NUM> operatively connected to the electric motor <NUM>. The data processing unit <NUM> is configured to control said electric motor <NUM>.

Turning back to <FIG>, the method <NUM> comprises a symbolic step of starting ST.

The method <NUM> comprises a step of (a) determining <NUM>, by the data processing unit <NUM>, a magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity.

The magnitude GR variable over time has a substantially periodic trend.

The method <NUM> further comprises a step of (b) determining <NUM>, by the data processing unit <NUM>, respective time instants t1, t2, t3 of at least two points among a plurality of points HS, MS, TO of the periodic trend of the magnitude GR variable over time.

Each point of said plurality of points HS, MS, TO has a respective value GR1, GR2, GR3.

The respective time instant t1, t2, t3 of each point of said plurality of points HS, MS, TO are representative of instants of interaction of the user U with the physical exercise surface <NUM> of the treadmill <NUM> while running.

The method <NUM> further comprises a step of (c) determining <NUM>, by the data processing unit <NUM>, at least one running phase of the user U on the physical exercise surface <NUM> of the treadmill <NUM> on the basis of the respective time instants t1, t2, t3 of said at least two points determined from the plurality of points HS, MS, TO of the periodic trend of the magnitude GR variable over time.

The at least one running phase of a user U on the physical exercise surface <NUM> of the treadmill <NUM> is comprised within a plurality of running phases comprising: phase of flight between different feet; phase of overstride; phase of propulsion; phase of contact by the same foot; phase of flight of the same foot.

The method comprises a symbolic step of ending ED.

In an embodiment, in combination with the preceding one, shown by dashed lines in <FIG>, the step of (b) determining <NUM> comprises a step of (d) determining <NUM>, by the data processing unit <NUM>, a first time instant t1 of a first point HS of the periodic trend of the magnitude GR variable over time.

The first point HS has a first value GR1 in the first time instant t1.

The first time instant t1 of the first point HS is representative of an instant of interaction of a portion of a foot of the user U with the physical exercise surface <NUM>, at the beginning of the interaction of the foot of the user U with the physical exercise surface <NUM>.

In an embodiment, either alternatively to or in combination with the preceding ones, the step of (b) determining <NUM> further comprises a step of (e) determining <NUM>, by the data processing unit <NUM>, of a second time instant t2 of a second point MS of the periodic trend of the magnitude GR variable over time.

The second point MS has a second value GR2 in the second time instant t2.

The second time instant t2 of the second point MS is representative of the instant of interaction of the same foot of the user U with the physical exercise surface <NUM>, in which the vertical passing through the center of gravity of the body of the user U intersects a contact portion of the foot with the physical exercise surface <NUM>.

It is worth noting that the first point HS and the second point MS of the periodic trend of the magnitude GR variable over time was defined above with reference to <FIG> and <FIG>.

In an embodiment, in combination with the preceding ones, the step of (c) determining <NUM> further comprises a step of (f) calculating <NUM>, by the data processing unit <NUM>, a time difference ΔT between the second time instant t2 of the second point MS and the first time instant t1 of the first point HS.

The step of (c) determining <NUM> further comprises a step of (g) providing <NUM>, by the data processing unit <NUM>, an indication of a phase of overstride tsv while the user U runs on the treadmill (<NUM>) as a function of the determined time difference Δt.

It is worth noting that the phase of overstride tsv, compared with a reference time difference, is an indication of a parameter representative of the quality of the pace of the user U on the physical exercise surface <NUM>.

Indeed, the closer to zero is the determined time difference ΔT, the more acceptable is the phase of overstride tsv, and vice versa.

In an embodiment (not shown in the figures), either alternatively to or in combination with the preceding ones, the step of (b) determining <NUM> further comprises a step of determining, by the data processing unit, a third time instant t3 of a third point TO of the periodic trend of the magnitude GR variable over time.

The third point TO has a third value GR3 in third time instant t3.

The third time instant t3 of the third point TO is representative of the instant of interaction of a portion of a foot of the user U on the physical exercise surface <NUM>, before the foot is off the physical exercise surface <NUM> (beginning of phase of flight of the foot).

In an embodiment (not shown in the figures), in combination with the preceding one, the step of (c) determining <NUM> comprises a step of determining, by the data processing unit <NUM>, a phase of contact tc of a foot with a physical exercise surface <NUM> of the treadmill <NUM>.

The phase of contact tc of the foot, from the periodic trend over time of the variable magnitude GR, is determined as a further time difference between the third time instant t3 of the third point TO representative of the instant of interaction of a portion of the foot of the user U on the physical exercise surface <NUM> before the foot is off the physical exercise surface <NUM> (beginning of the phase of flight of the foot) and the first time instant t1 of the first point HS representative of the instant of interaction of a portion of the foot of the user U with the physical exercise surface <NUM> at the beginning of the interaction of the foot of the user U with the physical exercise surface <NUM> (beginning of the phase of overstride).

Furthermore, in an embodiment, in combination with the preceding one, the step of (c) determining <NUM> comprises a step of providing, by the data processing unit <NUM>, the phase of overstride tsv as dimensionless ratio (possibly as a percentage) between the time difference Δt representative of the phase of overstride tsv and the further time difference representative of the phase of contact tc of the foot.

In an embodiment, not shown in the figures, either alternatively to or in combination with the preceding ones, the step of (c) determining <NUM> comprises a step of determining, by the data processing unit <NUM>, a phase of propulsion tp of a foot with a physical exercise surface <NUM> of the treadmill <NUM>.

The phase of propulsion tp of the foot, from the periodic trend over time of variable magnitude GR, is determined as a further time difference between the third time instant t3 of the third point (TO1 in <FIG>) representative of the instant of interaction of a portion of the foot of the user U on the physical exercise surface <NUM>, before the foot is off the physical exercise surface <NUM> (beginning of phase of flight of the foot) and the second time instant t2 of the second point MS representative of the instant of interaction of the foot of the user U with the physical exercise surface <NUM> in which the vertical line passing through the center of gravity of the body of the user U intersects a contact portion of the foot with the physical exercise surface <NUM> (beginning of the phase of propulsion tp).

In a further embodiment, not shown in the figures, in combination with the preceding ones, the step of (b) determining <NUM> comprises a step of determining, by the data processing unit <NUM>, a further time instant t6 of a further third point TO of the periodic trend of the magnitude GR variable over time. The further third point TO has a respective third value GR3.

The further time instant t6 of the further third point TO is representative of the instant of interaction of a portion of a foot of the user U on the physical exercise surface <NUM>, before the preceding foot is off the physical exercise surface <NUM> (beginning of phase of flight of the foot).

Indeed, the further time instant t6 is such that the first time instant t1 of the first point HS is comprised between the further time instant t6 and the second time instant t2.

The first value GR1 of first point HS is comprised between the third value GR3 of the third point TO and the second value GR2 of the second point MS.

It is also worth noting that the further third point TO of the periodic trend of magnitude GR variable over time is entirely similar to the third point TO, even if referred to the other foot, defined above, with reference to <FIG> and <FIG>.

In this embodiment, the step of (c) determining <NUM> further comprises a step of calculating, by the data processing unit <NUM>, a further time difference between the further third time instant t6 of the further third point TO and the first time instant t1 of the first point HS. The further third point TO and the first point HS are related to different feet.

In this embodiment, the step of (c) determining <NUM> further comprises a step of providing, by the data processing unit <NUM>, an indication of a phase of flight tv1 between different feet while the user U runs as a function of the further determined time difference.

In a further embodiment, either alternatively to or in combination with the preceding ones, the step of determining <NUM> further comprises a step of calculating, by the data processing unit <NUM>, a further time difference between the third time instant t3 of the third point TO and the first time instant t1 of the first point HS.

The third point TO and the first point HS are related to the same foot but belong to two successive periods relating to the same foot in the trend over time of the magnitude GR variable over time (in <FIG>).

In this embodiment, the step of (c) determining <NUM> further comprises a step of providing, by the data processing unit <NUM>, an indication of a phase of flight tv2 of the same foot while the user U runs as a function of the further determined time difference.

According to a further embodiment which is not part of the invention, in combination with any one of those described above, the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is a first absorption electric current I1 of the electric motor <NUM>.

In this embodiment, the step of (a) determining <NUM> comprises a step of detecting, by the data processing unit <NUM>, the first absorption electric current I1 of the electric motor <NUM> (not shown in the figures).

In greater detail, as mentioned above, the first absorption electric current I1 can be detected directly by the data processing unit <NUM> or by using a detection unit operatively associated with the processing unit <NUM>, described above in accordance with various embodiments.

With reference to the embodiment in <FIG>, which is not part of the invention, in combination with the preceding one, the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is a first absorption electric current I1 of the electric motor <NUM>.

In this embodiment, the electric motor <NUM> is a three-phase motor supplied by a triad of supply currents.

Furthermore, the treadmill <NUM> comprises at least one speed sensor <NUM> operatively connected to the electric motor <NUM> and to the data processing unit <NUM>.

In this embodiment, alternative to the one just described but in combination with any of the other preceding ones, the step of determining <NUM> the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity comprises steps of:.

In both the embodiments just described (<FIG> and <FIG>), in which the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the first absorption electric current I1 of the electric motor <NUM>, the step of (e) determining <NUM> the second time instant t2 of the second point MS of the periodic trend of magnitude GR variable over time comprises a step of calculating the second time instant t2 of the second point MS having a second value IV2 as maximum value.

This is performed, for example, by comparing successive samples, stored instant by instant, of the periodic trend of the first absorption electric current I1 of the electric motor <NUM>, once the step corresponding to one of a foot or the other foot (e.g. by selecting one foot at each even climb front and the other foot at each odd climb front).

In particular, the maximum value corresponding to the second point MS is determined by evaluating a current sample of the first absorption electric current I1 of the electric motor <NUM> with respect to a last stored maximum value of first absorption electric current I1 of the electric motor <NUM>.

In this embodiment, the step of (d) determining <NUM>, by the data processing unit <NUM>, the first time instant t1 of the first point HS of the periodic trend of the first absorption electric current I1 of the electric motor <NUM> comprises a step of determining a first value IV1 of the first point HS at the first time instant t1.

In an embodiment, the first value IV1 is determined as the minimum value of the derivative of the periodic trend over time of the first absorption electric current I1 of the electric motor <NUM>, prior to the second point MS.

The first time instant t1 is determined by the periodic trend over time of the first absorption electric current I1 of the electric motor <NUM>, at the first value IV1.

In the embodiment just described, in which the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the first absorption electric current I1 of the electric motor <NUM>, the step of determining the third time instant t3 the third point TO of the periodic trend of magnitude GR variable over time comprises a step of calculating the third point TO having a third value IV3 in the third time instant t3 as minimum value.

Once again, the minimum value corresponding to the third point TO is determined by evaluating a current sample of the first absorption electric current I1 of the electric motor <NUM> with respect to a last stored minimum value of first absorption electric current I1 of the electric motor <NUM>.

In accordance with an embodiment which is not part of the invention, in combination with any one of those described above but as an alternative to those in which the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the first absorption electric current I1 of the electric motor <NUM>, the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the instantaneous rotation speed VR of the electric motor <NUM>.

According to an embodiment, in combination with the preceding one, the step of determining <NUM> the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity comprises a step of detecting <NUM>, by at least one speed sensor <NUM>, the instantaneous rotational speed VR of the electric motor <NUM>.

In this embodiment, the step of (d) determining <NUM> the first time instant t1 of the first point HS of the periodic trend of the instantaneous rotational speed VR of the electric motor <NUM> comprises steps of:.

So, with respect to the embodiments in which the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the first absorption electric current I1 of the electric motor <NUM>, determining the first time instant t1 of the first value HS if the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the instantaneous rotation speed VR of the electric motor <NUM>, is simpler and more reliable.

Furthermore, in this embodiment, the step of (e) determining <NUM> the second time instant t2 of the second point MS of the periodic trend of the magnitude GR variable over time comprises a step of calculating the second point MS having a second value VR2 in the second time instant (t2) as minimum value.

This is performed, for example, by comparing successive samples, stored instant by instant, of the periodic trend of the instantaneous rotation speed VR of the electric motor <NUM>, once the step corresponding to one of a foot or the other foot (e.g. by selecting one foot at each even climb front and the other foot at each odd climb front).

In particular, the minimum value corresponding to the second point MS is determined by evaluating a current sample of the instantaneous rotation speed VR of the electric motor <NUM> with respect to a last stored minimum instantaneous rotation speed value VR of the electric motor <NUM>.

In the embodiment just described, in which the magnitude GR variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity is the instantaneous rotation speed VR of the electric motor <NUM>, the step of determining, by the data processing unit <NUM>, the third time instant t3 of the third point TO of the periodic trend of magnitude GR variable over time comprises a step of calculating the third point TO having a third value VR3 in the third time instant t3 as maximum value.

In this case, the maximum value, corresponding to the third point TO, is determined by evaluating at successive instants a current sample of the instantaneous rotation speed VR of the electric motor <NUM> with respect to a last stored maximum value of the instantaneous rotation speed VR of the electric motor <NUM>.

In accordance with a further embodiment which is not part of the invention, (not shown in the figures), either in combination with or as an alternative to any of those described previously, the method <NUM> comprises a step of detecting, by at least one distance sensor <NUM> (e.g. an infrared sensor) with which the treadmill <NUM> is fitted, operatively connected to the data processing unit <NUM>, a position variation of a portion (e.g. about the knee) of a set leg of the user U (right or left) while performing the physical activity on the treadmill <NUM>, with respect to a reference position (represented by the at least one distance sensor <NUM>).

The method further comprises a step of associating, by the data processing unit <NUM>, a respective piece of information representative of which foot the running phase refers to with each running phase of the user U on the physical exercise surface <NUM> of the treadmill <NUM> determined based on said at least two points determined from the plurality of points HS, MS, TO of the periodic trend of the magnitude GR variable over time.

In this embodiment, the method <NUM> further comprising a step of providing, by the data processing unit <NUM>, an indication of the presence or not of asymmetries during the running phases of the user U on the physical exercise surface <NUM> of the treadmill <NUM>, based on the running phases of the user U on the physical exercise surface <NUM> of the treadmill <NUM> determined with the associated respective piece of information representative of which foot of the leg the running phase refers to.

Indeed, by way of example, indication of asymmetries in the running phases can be provided by evaluating the phase of overstride of the right leg with respect to overstride of the left leg, the phase of contact of the right foot with respect to the phase of contact of the left foot, and so on.

It is worth noting that the detectable asymmetries are indicative of the running quality of the user U on the physical exercise surface <NUM> of the treadmill <NUM>.

With general reference to <FIG>, it is worth reasserting that, in an embodiment, the data processing unit <NUM> comprises a first data processing block <NUM> operatively connected to the electric motor <NUM>, the data processing unit <NUM> also comprising a second data processing block <NUM>, the second data processing block <NUM> being remote with respect to the first data processing block <NUM>.

In accordance with one embodiment, the steps a)-c) of the method <NUM> are performed by the first data processing block <NUM> of the data processing unit <NUM>.

In accordance with a further embodiment, alternative to the preceding one, the step (a) of the method <NUM> is performed by the first data processing block <NUM> of the data processing unit <NUM>, steps b)-c) of the method <NUM> instead being performed by the second data processing block <NUM> of the data processing unit <NUM> on the basis of the processed data received from the first data processing block <NUM> of the data processing unit <NUM>.

As apparent, the object of the invention is fully achieved because the method according to the present invention allows to determine running phases of a user on a treadmill without the user needing to be equipped with electronic devices, sensors or other equivalent devices, which could hinder the user's workout on the treadmill.

It is also possible to provide an indication representative of running phases to the user, such as a phase of flight between different feet, a phase of overstride, a phase of propulsion, a phase of contact of the same foot, a phase of flight of the same foot.

Again, instantaneous feedback can be provided to the user with the possibility of promptly correcting running quality, e.g. by receiving tips on how to modify and improve the pace (e.g. by increasing it).

Again, a plurality of parameters designed to identify more and more the user's pace while running and the running quality can be detected from the periodic trend of magnitude GR variable in time.

Furthermore, the detection of a magnitude variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> while performing the physical activity and the determination, starting therefrom, of characteristic points (first point HS - heel strike - of a first foot; second point MS - mid stance - of the first foot; third point TO - toe off a second foot, adapted to come into contact with the physical exercise surface before the first foot) allow to obtain the indication on the previously defined running phases.

In addition, the particular embodiment in which the magnitude variable over time correlated to the interaction of the user U with the physical exercise surface <NUM> is the instantaneous rotation speed of the electric motor allows to considerably increase the reliability and accuracy of the indication provided.

Claim 1:
Method (<NUM>) for determining running phases of a user (U) on a treadmill (<NUM>), the treadmill (<NUM>) comprising:
- a base (<NUM>) extending along a longitudinal axis (L), said base (<NUM>) comprising:
- a first rotating element (<NUM>) and a second rotating element (<NUM>) adapted to rotate around respective rotational axes (A2, A3) transverse to the longitudinal axis (L) of the base (<NUM>);
- a physical exercise surface (<NUM>) operatively connected to the first rotating element (<NUM>) and to the second rotating element (<NUM>);
- an electric motor (<NUM>) operatively associated with at least one of said first rotating element (<NUM>) and second rotating element (<NUM>), the electric motor (<NUM>) being configured to make the first rotating element (<NUM>) and the second rotating element (<NUM>) rotate, also driving the physical exercise surface (<NUM>) into rotation;
- a data processing unit (<NUM>) operatively connected to the electric motor (<NUM>), the data processing unit (<NUM>) being configured to control said electric motor (<NUM>),
the method (<NUM>) comprising steps of:
- (a) determining (<NUM>), by the data processing unit (<NUM>), a magnitude (GR) variable over time correlated to the interaction of the user (U) with the physical exercise surface (<NUM>) while performing the physical activity, the magnitude (GR) variable over time having a substantially periodic trend, the magnitude (GR) variable over time correlated to the interaction of the user (U) with the physical exercise surface (<NUM>) while performing the physical activity being the instantaneous rotational speed (VR) of the electric motor (<NUM>);
- (b) determining (<NUM>), by the data processing unit (<NUM>), respective time instants (t1, t2, t3) of at least two points among a plurality of points (HS, MS, TO) of the periodic trend of the magnitude (GR) variable over time, the respective time instants (t1, t2, t3) of each point of said plurality of points (HS, MS, TO) being representative of instants of the interaction of the user (U) with the physical exercise surface (<NUM>) of the treadmill (<NUM>) while running;
- (c) determining (<NUM>), by the data processing unit (<NUM>), at least one running phase of the user (U) on the physical exercise surface (<NUM>) of the treadmill (<NUM>) as a function of the respective time instants (t1, t2, t3) of said at least two points determined from the plurality of points (HS, MS, TO) of the periodic trend of the magnitude (GR) variable over time.