WO2007048431A2

WO2007048431A2 - Force sensor for bicycle, training aid

Info

Publication number: WO2007048431A2
Application number: PCT/EP2005/011572
Authority: WO
Inventors: Jean-Marc Ferme
Original assignee: Jean-Marc Ferme
Priority date: 2005-10-28
Filing date: 2005-10-28
Publication date: 2007-05-03
Also published as: WO2007048431A3

Abstract

The invention concerns a method for calculating the useful torque imparted by a cyclist to a bicycle, by detecting the angular acceleration of the chainset (2) and searching for local minima to determine the resultant of external efforts in combination with the transmission gear ratio, the computation of which is performed using data from the magnetic sensor (4). The invention concerns an adequate method for measuring the movement of the chainset (2) by a self-adapting detector (3) operating directly on the teeth of a chainset, insensitive to ambient light, and delivering with precision and the bandwidth required the information to an onboard central processing unit (1) for computation, the graphic display, the audio signalling, the recording and the digital reproduction of the acceleration, the useful torque, the instantaneous, average, maximum power, the energy consumed in three categories of biochemical resources during the course. The invention also concerns an integral standalone device using said methods allowing a cyclist to maximize his performance and avoid harmful muscular overstrains. Other devices may be used for detecting the movement of the chainset or computing the gear ratio.

Description

Bicycle effort sensor, training assistance

Technical area :

The invention is a device embedded on a bicycle, allowing its driver to be informed at all times the status of his performance on a given course. The device can therefore be used for sports training purposes or information or recording during an excursion. 0

Whatever the path profile and the aerodynamic conditions, this device is capable of measuring, graphically displaying, accurately recording the speed of rotation and the angular acceleration of the pedal, to calculate the engine torque provided by the cyclist , the instantaneous power output provided as well as the energy expended by a cyclist and his cardiac activity; this information is correlated with other quantities known in advance, measured or calculated such as the weight of the cyclist, the speed or position of the bicycle in a given course, the temperature and the air pressure.

The device makes it possible to locate the effort provided by the cyclist, in the so - called anaerobic alactic zone, or in the lactic anaerobic zone, or finally in the aerobic zone. Fig. 03 5 represents a typical curve of muscular energy expenditure, during which all the first two biochemical energy sectors are exhausted at the beginning of the effort. A profile of power and energy expenditure below the curve (93) will not cause inconvenience to the cyclist. On the other hand, any 0 overpowering of the curve (93) will result in a penalty, which the cyclist will have to pay later in the form of either excessive stressing of the cardiovascular system, premature exhaustion, or muscle soreness due to excess production of lactic acid. The rest periods, either when the freewheel is used or during a break, are also recorded in order to follow the physical recovery of the cyclist.

• The invention is of particular importance because the 0 reaction of the cyclist 's cardiovascular system is always • The invention is of particular importance, because the reaction of the cyclist's cardiovascular system is always consistent with the effort provided, and therefore always late compared to the action. The device thus allows the cyclist to optimize in real time the use of his muscular resources and to avoid penalizing overloads.

• Because the invention does not alter the mechanical structure of the bicycle, the integrity of the original bicycle is retained. There is no different behavior of the bicycle before and after assembly of the invention. The principle, the capabilities to fulfill its function, the comfort and the driving sensations of the bicycle remain the same. This is essential in view of the extremely intense efforts that can be developed by athletes.

• The system is not subject to mechanical wear. • It is not necessary to disassemble any part of the bicycle to install the system.

• The invention directly uses the teeth of the trays to detect the essential parameters required. There is no encoder wheel to add. • Given the small number of components to add, the weight of the bicycle will not be affected too much by the invention, which will satisfy the athletes concerned about the weight of their equipment.

• In case of system failure, the operation of the bicycle is not impaired

• The visualization of the information is done by a graphic screen, offering a greater flexibility and a more varied choice in the presentation of the information than with a traditional digital display.

Prior art:

The first equipment historically realized were the mileage counters and speed indicators, then came the indicators of pedaling rhythm. Most of these devices are still able today only to detect average values, because the signal comes from a single generally magnetic singularity mounted on the movable member in rotation and delivering a magnetic pulse to the sensor attached to a portion of the frame of the bicycle, for each complete turn performed. The frequency of this sampling is therefore reduced. Given the intrinsically pulsating nature of the effort provided by the cyclist, any variation in speed which results in a rotation cycle can not be observed.

Proposals have been made to include a greater number of magnetic singularities in the pedalboard, but they typically lead either to the replacement of a component of the existing pedalboard, or to the creation of measurement noise directly related to inaccuracy. angular positioning of the singularities.

The measurement of forces exerted by the chain on the bearings of the rear wheel hub 95 is proposed in (WO0130643).

The measurements thus obtained are not always representative of the useful torque, have a very low dynamics, a very low signal-to-noise ratio because the intrinsically high rigidity of the constituent elements of the bicycle limits the range of use of the sensors.

In certain inventions elastic deformable devices have been introduced into the transmission elements of the forces which are useful for the propulsion of the bicycle, in order to

105 to mechanically amplify the deformations to be measured. Thus there are elastically deformable elements inserted in the bottom bracket, which can measure with greater sensitivity the component of the radial force exerted on this bearing in a fixed direction given in advance (JP2002082003).

110 However, the component of the radial force on the bearing in a given direction is not always a good approximation of the useful torque: to give a correct result, the radial force must be vectorially combined with the torque-generating levers arms. useful, dependent values from the angle

115 instantaneous rotation of the crankset, or of the combination trays-sprockets current. The measurement of micro-deformations due to the bending moment exerted on a pedal arm is one of the first direct methods

120 to have been experimented, does not have great dynamics of measurement.

A proposal (DE 34 46 689 A1) introduces an elastic element with strain gauge mounted on the movable assembly of the trays; an electronic circuit ensures the conditioning of the

125 signal and its transmission to a receiver located nearby on the frame of the bicycle. In addition to the fact that the object is rather bulky and that it is necessary to make significant changes in a place where the place is lacking, the system must have an autonomous power supply.

130

In the invention JP10035567, the proposed method does not allow measurement of the torque provided by a single leg of the cyclist.

One of the most interesting published system (US5031455) is

135 consists of a new rear hub with torsion springs making an elastic coupling between the force transmitted by the chain and the rear wheel. An original device for combined measurement of the force and the speed of rotation was proposed. An optical sensor was proposed, whose very schematic

The rudimentary 140 could not guarantee its use in the environmental conditions of an outdoor bicycle. In addition, this system did not manage the combination plateau-pinion and therefore the calculation of the developed useful power was difficult to exploit.

145

Recent products have appeared on the market, including a GPS positioning system, but none incorporates an instantaneous torque measurement associated with a device for monitoring the energy resources of the cyclist.

150

Lastly, functional laboratory ergometers or certain training equipment already have power measuring devices, but their principles are not applicable to a bicycle that normally moves for the purpose.

155 to travel on a route without technical assistance. The result of the situation is that today, the market offers some products that have not experienced a real commercial boom. In addition, the current equipment can only display 160 cyclically refreshed numerical values, but these displays do not allow to graph the quantities, nor to represent them in the form of history.

165 Statement of the Invention:

The invention uses an original and sequential method for estimating the external forces applied to the bicycle - bicycle assembly, thereby making it possible to calculate the useful torque 170 supplied.

In order to illuminate the presentation of the useful torque measurement principle, reference is made to FIG. 02 where the bicycle / bicycle system and the main parameters 175 governing the movement have been modeled. The expression [3] shows the relation between the teta "angular acceleration, the useful torque C, the external forces including the action of the gravity, and this expression is valid only when there is no Freewheel effect 180

Assuming that one can measure the teta "angular acceleration very precisely, the expression [3] contains two unknowns, the useful torque C that one wants to measure, and the components of the external forces. invention will use 185 in principle a particularity of the system related to the cyclic and quasi-discontinuous appearance of the application of the engine torque: • In the absence of freewheeling operation, which is the normal case, the useful torque C passes twice per cycle by a minimum value, this inside the high dead band 190 or bottom of the pedal (6), it is possible to define the dead band by the angular zone of rotation of the pedal (6) in which the pedal A dead end arm can be simply defined in advance by a frame of the values 195 of angles of rotation of the pedal (6), or well by detection and locating the relative minimum of the angular acceleration that is by definition within the dead band, or by detecting the concavity of the angular acceleration curve.

200 Λ inside the dead band or at the passage of teta ^ΛΛ by the minimum, the corresponding term (n ₂ / n) ² C in [3] becomes negligible. So in the dead band or at least the angular acceleration teta ", the measure of the angular acceleration of the crankset teta" gives precisely a value

205 proportional to the sum of the external forces applied to the bicycle-bicycle system.

The duration of a cycle of rotation of the pedal (6) is about one second for a walk (0.6 seconds for a race), and it can rightly be considered that external efforts

210 applied to the bicycle rider will not vary significantly over half a cycle. So, if we use a method consisting of storing during the passage in each high or low dead band the value of the relative minimum téta " _bπl of the acceleration, and that we subtract algebraically this

If the value stored in the next half-cycle is memorized to that of the acceleration, the useful torque C can be calculated from the expression [6] and so on. Note that it is also possible to calculate an average of the acceleration values measured in the deadband, instead of

220 of the value of the minimum teta ^ΛΛ _bm , or the filtering of the value of the minima teta " _bm measured at each half-cycle, and use the value thus filtered in the sequential calculation as described above.

In practice, it is possible to illustrate the cases of application of this method by the diagrams of FIG. 02A, Fig. 02B, Fig. 02C, which represent the temporal evolution of the main states that are useful for the presentation for different path profiles, respectively, ascent up, descent start,

230 slowdown uphill. The markers represent the same magnitudes on each figure concerned. We note the very different character of these curves as a function of the path profile. In principle, there is no real limitation to the application of this method. The acceleration measurement teta "n" is valid only as long as the rider keeps pedaling the freewheel locked in torque transmission to the rear wheel.The whole thing is to have a sufficiently rich, dynamic information, and at a minimum. sampling frequency well 240 greater than IHz.

The invention proposes an original method for detecting the angular acceleration of the crankset, ie the direct use of the toothing of one of the existing plates (7) (8) (9) on the

245 bicycle and a motion sensor which detects the passage of the teeth in the normal conditions of use of the bicycle and calculates the duration of passage of a tooth, or two or more teeth to deduce the angular rotation speed. teta 'and teta angular acceleration. "This detection is part of

250 as a whole, because it is in fact only an extension of the embedded central unit.

On the other hand, the "non-regular" plates, for which the winding diameter is not constant, are unfit for this purpose and the addition of a high-density coding wheel of

255 singularities on the shaft (5) of the pedalboard is an alternative.

The method of optical detection of the passage of teeth is based on a particular control sequence of an optoelectronic component. Indeed, it is necessary to detect the useful signal of the surrounding noise, here created by ambient light, natural or artificial, essentially variable on a path.

The value of the reduction ratio between the active plate and the pinion in service is essential to calculate the 265 torque. It is therefore necessary to add to the system a real-time calculation of the gear ratio n ₂ / n, failing to have the information directly from the derailleurs or their control system.

The information extracted from the described principle is processed by the onboard processing unit (1) and is graphically displayed on its screen and recorded sequentially for further processing on another non-embedded computer. Central unity Onboard also handles other signals such as the distance traveled pulses or the position obtained by a global positioning system (Gobai Positioning System), the atmospheric pressure, the temperature of the air.

The invention is therefore also an onboard system enabling the cyclist to prepare his strategy and adapt his racing tactics while following the course according to his own physiological data, the course profile, the conditions of the race. environment and the estimation of its aerobic and anaerobic energy expenditure (lactic or alactic) and 285 of the estimated state of its reserves in ATP (Adenosine Tri-Phosphate).

The instantaneous power supplied by the cyclist is compared to the registered cyclist's personalized physiological values and

290 involuntary overloads whose penalty would be critical on the results of the excursion are reported accoustically. For example, the use of anaerobic pathways is crucial and only highly trained athletes have personal knowledge of their limitations, knowledge gained through training

295 successive. On the other hand, a cyclist who has not been specially trained may involuntarily deplete his reserves rapidly.

A. T. P. in a given sector and realize it only too late.

Auxiliary monitoring of cyclist's cardiac activity

300 by an independent system is recommended in all cases.

Brief description of the drawings:

305 Fig.01: general view of the system consisting of the on-board CPU (1), the pedal-plate assembly (2), the equipped plate (3) for taking information from the pedal, the magnetic sensor ( 4) rotation of the bicycle wheel. The interconnection (not shown) of the components is in principle

310 made by electric cable. Fig.02: Main equations that govern the system. [1] gives the equivalent mass M of the frame-cyclist assembly (mi), and wheels (m).

315 [2] gives the equivalent inertia J of the system reduced to the axis of rotation of the pedal.

[3] gives the equation of the movement of the angular rotation of the pedal, in which C is the engine torque applied by the cyclist on the pedal, n and n ₂ respectively the number of

320 teeth of the plate and that of the gear used, teta is the angular rotation of the pedal, teta 'the angular velocity and teta' is the angular acceleration of the pedal, teta _r is the angular rotation of the rear wheel, alpha the inclination of the plan on which the bicycle moves in relation to the horizontal,

325 r the radius of the rear and front wheels, g is the acceleration of gravity, F _r the friction forces between the wheels and the ground, and F _v all other external forces acting on the bicycle and the cyclist (wind , etc ...). This expression is valid outside the freewheeling periods, ie when the

The cyclist contributes almost continuously to the propulsive effort.

[4] expresses the non-slip rolling relationship between the X translation movement of the bicycle on the ground and the rotational movement of the rear wheel.

335 [5] expresses the relation [3] for each minimum in the dead band. Teta " _bm is a stored value.

[6] expresses the relation [3] between two dead spots and in the absence of coasting operation. It makes it possible to calculate C on the basis of the value Teta " _bm memorized at the point

340 previous death.

Fig. 02A: The graph shows the evolution of the acceleration teta "(122) during a part of the pedals rotation cycle In the dead band (121), the useful torque C is almost zero 345 and the acceleration measured teta is representative of external efforts; it has the value (120) teta " _bm at the relative minimum The signals are in fact sampled at all delta t (132), which applies to the angular rotation speed signal (125). 350 The points (126) and (127) represent the points of a pedal rotation speed measurement on a complete pedal revolution, and show that the latitudinal sampling does not allow to have access to the fast variations of the states . On the other hand, the sampling (132) makes it possible to follow the speed signal

355 with good accuracy (between 30 and more than 50 samples per revolution).

The calculated torque curve (128).

The instantaneous power curve (129) intercepts the power threshold (131). The average power is represented by the

360 dotted curve (130).

F ± g. 02B: Evolution of the same curves as in FIG. 02A, but in a situation where the result of actions outside the bicycle and the cyclist gives a component (120) positive 365 (as for example during a descent).

F ± g. 02C: Evolution of the same curves as in Fig. 02A, but in a situation where the result of actions outside the bicycle and the cyclist gives a component (120) very negative 370 (such as during a climb and when the contribution of the cyclist fails to maintain its constant speed ).

Fig. 02D: Simplified algorithm for calculating the torque, the

375 power, and energy.

The signal (141) from the magnetic sensor (4) Fig. 01 triggers the calculation of the gear ratio n / n _{2 based} on the number of pulses (140) generated by the motion detection (16). 05 with each pass of a plateau tooth. The

380 formula (146) shows that one can perform the calculation between two pulses (141) of the magnetic sensor signal (4) or more, in order to improve the accuracy of calculation. The other asynchronous algorithm of the previous one is triggered by the pulse (140) of the motion detection (16). 05 to

385 each passage of one tooth or more, according to the value given to i.

The speed of rotation and the acceleration are calculated in (142), and depending on the passage of the acceleration teta ^ΛΛ n by a minimum, the comparator (143) selects the calculation (144) of the useful torque and other states after exceeding the minimum, or

390 well the search for the strict or relative local minimum and its memorization (145).

Fig. 03: Available power curves during an example of muscular energy expenditure. Curve (90) represents the anaerobic alactic contribution of creatine and

395 phosphocreatine. The curve (91) represents the lactic anaerobic contribution, the curve (92) aerobically the contribution of the aerobic die. The curve (93) represents the sum of the contributions. The threshold (94) decides the passage between the consumption of the resources of the alactic or anaerobic

400 of the lactic anaerobic sector.

The threshold (95) decides the passage between the consumption of the resources of the lactic anaerobic sector or the aerobic sector. The curve (93) and the thresholds (94) (95) are displayed graphically on the screen (51) Fig.10, and when the

When the cursor reaches the right end of the screen, the cursor restarts to the left of the screen erasing the previous data with each subsequent movement to the right.

Fig. 03A: Display of ATP resources on the on-board central unit (1): three counters (96) (101) (106) respectively representing the resources of the three anaerobic alactic, anaerobic lactic, aerobic, the remaining resources indicated by the height of the graphical bar

(97) (102) (107). The value in unit of time during which one 415 uses one of the resources is given by the indication

(98) (103) (108). For each resource (96) (101) (106) it is possible to display the value of the heart rate and the extrema

(99) (100), (104) (105), (109) (110).

420 FIG. 05: Partial section of a pedalboard (6) with three trays equipped for the example of two motion sensors, one transmissive (15) on the outer ring, the other reflective (13) measuring the angular rotation of the plate (9). These two examples of configuration make it possible to measure the rotation

425 angular crew of trays (7) (8) (9) on which one meshes the traction chain (19). Fig. 05A: detail of the fixing of the sensor holder bracket (17) covered with an adhesive coating on the frame (12) of the bicycle 430 by means of an elastic link (18). The pressure exerted by the elastic tie keeps the square in position.

Fig. 07: Schematic diagram of optical motion detection: a clock (31) synchronizes the emission of photons by the diode

435 electroluminescent transceiver pair (30) with the control of a follower-memory device (32) and the triggering of a state memory (33). The transceiver torque receiver signal (30) is filtered by a unit (34) and continuously supplies the non-inverting input of the comparator (36).

440 When the light emitting diode of the transceiver pair (30) is not energized, the transistor (32) is on and the capacitor (35) records the average value of the ambient illumination of the transceiver pair (30). When the light-emitting diode of the transceiver pair

445 (30) is energized, the transistor (32) is turned off, allowing the comparator (36) to compare the current value of the output of the transceiver pair (30) with the value of the stored ambient illumination. In the case of the reflective sensor Fig. 05 (13), the presence of a

450 tooth in the path of the emitted light beam will cause a state change of the comparator (36) which will be stored in the memory (33).

In the case of the transmissive sensor Fig. 05 (15), the absence of a tooth in the path of the light beam will cause a change

455 comparator (36) which will be stored in the detector (33).

In other cases, the sensor does not detect a change in illumination.

460 Fig. 07A: The timing diagram shows a sequence of detection of the passage of a tooth of the plate (7) (8) (9) in front of one of the transceiver pair (30). This sequence applies either to the transmissive sensor (15) for the case of the absence of tooth for the edges (40) (41) and the presence of plateau tooth for

465 the step (49) or the reflective sensor (13) for the case of the presence of tooth for the edges (40) (41) and the absence of plateau tooth for the step (49).

the influence of the rising edge of the control signal (40) coming from

470 (31) on starting the comparison of the voltage (43) from the phototransistor of the transceiver pair (30) and going to the input of the comparator (36), while the transistor (32) blocks the voltage ( 44) from the phototransistor of the transceiver pair (30) which is now isolated and under

475 dependence of the device (35) and feeds the other input of the comparator (36). As the phototransistor of the transceiver pair (30) receives photons emitted by the light emitting diode, the current flowing therethrough increases and is added to that generated by the ambient illumination; when

480 the voltage (43) exceeds the threshold (42), depending on the reaction on the output (37), the comparator changes state (45). It is only at the arrival of the falling edge (41) of the control signal coming from (31) that the state of the output (38) of the comparator (36) will be memorized (47) by (33) before the fallout of

485 front (46). Since the light-emitting diode is no longer powered, the output voltage of the phototransistor of the transceiver pair (30) returns to the value imposed by the ambient illumination, and the transistor (32) is again conductive and the voltage of the device ( 35) goes back to following the

490 value of the ambient illumination. The output of the comparator (36) returns to zero but can not pass through (33). The following cycle is similarly performed, with the difference that the absence of photons received by the phototransistor of the transceiver pair (30) does not affect the current flowing through it.

495 and the voltage (43) remains equal to that given by the ambient illumination. The comparator (36) will not change state. When the falling edge of the control step (49) arrives, the output of the comparator (36) already at zero will be memorized by (33) whose output will change on the front (48).

500

Fig. 08: reflective sensor (13) equipped with the sun screen brush (25) also protecting the sensor against dirt 505 Fig- 09: Transmissive sensor (15) equipped with the sun screen brush (25) also protecting the sensor against dirt

Fig. 10: embedded central unit as shown schematically. 510 (1) comprising a watertight housing (50), a graphic display (51), micro-contacts (53) (54) (55) for controlling the functions of the equipment, a connector (56) ) used for connecting the on-board CPU (1) with the different sensors Fig. 05 (14) (16) and FIG. 01 (4), a connector (57) for connection with an additional GPS unit or with a PC computer for operating recordings or setting parameters of the on - board CPU, and a connector (58) for auxiliary power supply. An assembly (52) of a battery or accumulator module and a solar module provides the normal supply 520 of the onboard CPU (1) and its sensors.

Mechanical fasteners are provided for fixing the central unit on the handlebar of the bicycle.

Fig. 11: Embedded CPU support. It comprises a flat section (62) mounted on the handlebar of the bicycle (60) with a tubular shock absorber (61) made of synthetic material, the whole being fixed by the plate (71) by means of the bolts (66). ) (67); the assembly is therefore adjustable, so as to maximize the comfort of operation and reading of the screen.

530 The onboard CPU (1) is held in the carrier and abuts on the damper (68), its interface connector FIG. 12 (56) is nested in the interface connector (72) of the support, and the upper part of the onboard CPU (1) is held by the locking 535 (69) (70), whose holding force is produced by the spring (65) and transmitted by the pins (63) and (64).

Fig. 12: Assembly of the interface connector (72) with the flat profile (62) and the damper (68). The interface connector 540 (72) is slidably mounted through the flat profile (62) so as not to transmit radial force to the onboard CPU (1). (73) represents the strands of the cable going to the different sensors. 545 Fig. 13: Oscillating motion sensor variant of the damped oscillator type. The coil (80) and its magnetic circuit are placed close to the ring gear (7). In the absence of metal toothing, the coil (80) and the associated capacitor (81) are controlled by the integrated circuit (82) operating on the

550 principle of the type Siemens TCA 355B or TCA 105 for example, and excited at their natural frequency. When a tooth approaches and passes in front of the end of the detector (80), the electrical losses caused in the toothing unbalance the oscillator and the integrated circuit (82) mounted on the wafer

555 (83) detects the presence of a tooth, signal sent to the onboard CPU (1).

Best way to realize the invention:

560

The algorithm presented in FIG. 02D makes it possible to follow the evolution of the calculations to be implemented.

First of all, we have to calculate the current gear ratio of the gearbox transmission (6).

565 to the rear wheel of the bicycle. The signal (141) coming from the magnetic sensor (4) for rotating the wheel of the bicycle triggers the counting of the counting of the pulses coming from a plate (7) or (8) or (9) which is known in advance. the number of teeth, the division according to the expression (146), the resetting of the

570 count of pulses coming from the board and whose counting is not interrupted. The precision obtained on n / n ₂ is of the order of the percent when i = 1, ie it is measured over a period of the signal (141). By using values higher than i, we acquire more precision and the values of i = 1 or i = 2 give

575 good results.

The second synchronized loop on the signal (140) coming from the passage of the teeth of a plate (7) or (8) or (9) in front of the motion detection (16) computes in sequence: • in (142), the speed rotation teta 'of the pedal (6),

580 obtained by the division of the time delta t multiplied by the number of samples i, by the difference in value T _n -T _n - _I of the counter of the clock of the on-board central unit (1), whose the frequency is typically 5 MHz. A value of i = 1 indicates that the velocity between two consecutive samples 585 is calculated, ie a calculation between two adjacent teeth. We can also get good results with i = 2, which gives a lower bandwidth but the benefit of a smoothing effect measures.

• (142) calculates the teta angular acceleration by dividing by 590 the speed difference between the result of the calculation above and the value calculated with the preceding sample, related to the time delta t multiplied by the number of samples i.

• (143) makes it possible to orient the calculation according to the new value of the acceleration teta ", the first time

595 the acceleration starts to increase after a series of decreasing values, indicating that we have just exceeded the relative minimum, we memorize the value of the minimum acceleration teta " _bm .

• (143) can also use another method to memorize the 600 value of the minimum of the acceleration teta "by using a priori knowledge of the location of the dead bands on a turn of board: one counts indeed the passage of the teeth in front the displacement sensor, it is possible to define angular rotation intervals within which a representative value which can be the average value or the minimum value of the angular acceleration, which will be stored for its use outside, is calculated. dead bands.

• (143) can also detect the concavity of the angular acceleration curve and allow to conclude at the entrance

610 in a dead band by the change of sign of the derivative of teta "with respect to time.

• (145) stores the value of the acceleration teta " _bm .

• (144) calculates the torque C according to the formulas indicated, then calculates the instantaneous power P _n , the cumulated energy E _n ,

615 the comparison with the power thresholds, according to which the resource counters (96) (101) (106) are incremented, and finally the value of the stored teta 'speed is updated for the next iteration. The end of (144) brings back the expectation of a new impulse coming from (140).

620 The realization of this method of measuring the torque requires very few modifications to be made to the bicycle and this represents a certain economic interest for consumers. One sensor Fig. 05 (15) or (13) is sufficient to measure the

625 angular rotation of the pedal (6). There is no preference on the use of this or that plate. The sensor (15) or (13) counts the passage of the teeth of the plate (7) or (8) or (9). However, the application of the method requires the use of an extremely precise and consuming tooth position sensor

630 little electrical energy for the detection of angular rotation teta Fig. 02. The usual cutting precision of the teeth of a plate is largely sufficient to guarantee the accuracy of the measurements. However, if the sensor is fitted to worn equipment

635 (worn toothing, worn chain, worn bearing), it is possible that these mechanical imperfections or excessive fouling disturb the measurement, but the replacement of these parts by new or their cleaning restores the quality of the measurement. The sensors chosen for the detection of the teeth are

Preferably, optical sensors or non-contact inductive sensors with damped oscillator or variable reluctance are preferred.

Optical detection whose schematic diagram given in FIG. 07 uses a transceiver pair (30) with a maximum of

645 sensitivity is in the infrared, for a wavelength of 950 nm, so as to deviate as much as possible from the peak of the frequencies contained in sunlight or artificial light. The detector is a phototransistor, but could also be a photodiode. A brush (25) made of synthetic fibers makes it possible to

650 limit the entry of direct sunlight on the phototransistor and also prevents dirt from dust or projected water, while letting the teeth of the trays freely. A second brush can be added to protect the sensor from dirt projections coming from the

655 lower part of the bicycle.

The proposed transceiver pair can be indifferently transmissive as shown in FIG. 09 or reflective 08, depending on the ease of installation on the bicycle. The transceiver pair (30) and the associated electronics Fig. 07

660 are mechanically assembled to form a unit with an output cable. A synthetic resin molding makes it possible to make the assembly in its (16) or (14) form. 05 waterproof and easy to mount on the plate (17) Fig. 05

665 The proposed detection method of which a chronogram is given in Fig. 07A, however, eliminates the ambient light level that could disturb the detection of the passage of teeth by the sensor. The transceiver pair (30) is therefore used sequentially on the one hand to measure the

670 ambient light level (its light-emitting diode being non-energized), which level is stored just before commissioning of its light-emitting diode, and secondly to measure with its phototransistor the energy received from its light-emitting diode fed . The comparison of the received signal

675 ambient light measurement phase with the signal received in the power supply phase of the light emitting diode makes it possible to decide on the presence of a tooth or its absence. The output state of the comparator (36) indicating the presence or absence of a tooth is stored (38) on the front (41) of

680 power failure of the light emitting diode.

For a large plate (7) equipped with 50 teeth, for example, the nominal rotation speed of the plate for high level pistars is 100 revolutions per minute, which gives a frequency of

685 83 Hz tooth pass, that of a road in good shape is around 80 revolutions per minute for endurance events (a frequency of 65 Hz). The maximum frequency of the oscillator (31) of the optical detection is preferably of the order of 20 to 50 kHz.

The power supply duration of the light-emitting diode is preferably of the order of 10 μs, ie 1/5 of the optical detection period, which makes it possible to reduce the electrical energy consumed.

In a preferred embodiment, the optical detection oscillator (31) is integrated with the optical detection FIG. 07, so as to avoid problems of electromagnetic compatibility, given the stiffness of the fronts of this clock. This clock can also be supplied from the on-board CPU (1),

700 but we should then pass this signal through cables; in this case, it is possible to cleverly combine the supply of the clock signals coming from (1) with an estimate of the arrival time of the next tooth front, so as to avoid feeding the optoelectronic transmitter when the system know

705 that the tooth will be present or absent for a certain time, depending on the pitch of the teeth and the speed of rotation teta 'of the plate. This produces a substantial energy saving. A hysteresis is created on the detection of passage of teeth,

710 to avoid the instabilities of detection, thanks to the reaction (37) on the comparator (36).

When the ambient illumination increases, the transfer coefficient (ratio of the current of the phototransistor by the current

715 of the light-emitting diode) of the transmitter-receiver

(30) also increases, and detection can be affected. A diode can be added in parallel with the charge (34) of the phototransistor, providing an automatic correction of the transfer coefficient.

720

Optical detection Fig. 07 is powered by the embedded central unit (1); the detected signal (38) is sent to the on-board CPU (1); it is the on-board CPU (1) that thus manages the power on or off of the module of

725 detection depending on the use of the complete system.

The calculated value of the useful torque C is then multiplied by the value of teta 'present, so as to obtain the useful instantaneous power. The sampling of the calculation of the useful torque C

730 and the instantaneous power P occurs at each passage of a new tooth or several teeth of the plate in front of the angular rotation sensor. On a wheel and for a 50-tooth plate, we usually have up to 50 samples, or 25, half, for the work of the leg

735 left and as much for the other leg.

The calculation of the energy is an accumulation of the instantaneous power values on a pedal revolution multiplied by the duration during which the torque C has been motor. For all numerical calculations of the expressions given in FIG.

740 02, some values must be recorded by the cyclist before the race, as its weight, that of the frame of the bicycle, of each wheel, so that the equivalent inertia J can be calculated.

The three A.T. P. channels are symbolized by dynamic accumulators, preloaded 100% for an excursion and visible on the graphic screen (51) of the onboard central unit (1). The accumulator of the Creatine Phosphocreneine CP (96) FIG. 03 will be decremented at each unit of time only when the

The cyclist's instantaneous power will exceed the predefined value (94) predefined by the cyclist in advance and an audible signal (series of rapid beeps) will be issued by the on-board central unit (1). Once the accumulator CP (96) empty, it will remain empty for the duration of the excursion, ie it will not fill

755 not again. On the other hand, if, during the excursion, the cyclist delivers a power again greater than Pl (94), this means that the value of P1 (94) has been underestimated, and the indication (98) will continue to evolve so as to give at the end of the excursion the final value reached. This value therefore allows

760 from one excursion to another, to measure the changes in fitness of the cyclist.

The accumulator AN (101) FIG. 03 of the lactic anaerobic branch is also decremented at each unit of time, as soon as the instantaneous power supplied by the cyclist is between

765 the value Pl (94) and the value P2 (95) also pre-defined in advance and a sound signal (series of slow beep) will be emitted by the onboard central unit (1). The accumulator AN (101) unlike CP (96) has the possibility of filling during the excursion, so as to represent the recovery and

770 elimination of lactic acid by the body. Continuous operation in the area P1 (94) P2 (95) will empty the accumulator AN (101) in typically 2 to 4 minutes, and the accumulator AN (101) will self-refill in typically 15 to 20 minutes (time constant T configurable at the start

775 of the excursion); that is to say that the cyclist will have the opportunity to provide a new effort in this sector if his excursion allows it. In this case, the cyclist is sure not to have a negative effect on his performance or physiology. The indication (103) is never saturated and

780 is incremented as soon as the power is in the area P1 (94) P2 (95). Finally, the last accumulator (106) of the aerobic die AE is decremented as soon as the instantaneous power supplied is greater than a minimum threshold (not shown) and less than the threshold P2 (95). As this sector is not limited in the

785 times and that the energy reserves of the cyclists are practically not exhaustible completely, this accumulator counter will fill again instantly when it is empty and the indication (108) will continue to be incremented until the end of the excursion .

790

For each die above, the minimum and maximum heart rate indicators (99) (100), (104) (105), (109) (110) located next to each accumulator (96), (101), (106) are updated according to the information available. All the

795 intermediate values remain displayed on their bar graph.

The time evolution of the instantaneous power (93) and the thresholds P1 (94) and P2 (95) represented in the form of horizontal line 800 dashed as in FIG. 03 are also available on the graphic display (51) of the onboard central unit (1), at the cyclist's choice.

When the on-board CPU (1) uses in real time the 805 position information from a Positioning sensor

Global (GPS) not shown, we add to the time evolution of the instantaneous power (93) a slider (113) which indicates to the cyclist what is the value of power that it should provide at this precise location of its course to 810 achieve its goal in accordance with its preparation.

Similarly, the accumulators (96) and (97) have a set slider respectively (111) and (112) which allow the cyclist to know at this specific point of the course what should be the state of his reserves. 815

Ways to realize the invention

The description given is for a bicycle equipped with any number of trays. The light-emitting diodes of the optical sensors can be replaced by optically focused or non-optically focussed laser diodes, which improve the immunity to ambient light at the expense of the electrical consumption, however. Of

825 even the phototransistor can be replaced by a photodiode associated with an amplifier (transistor or operational amplifier JFET).

The optical sensors can be replaced by damped oscillator sensors of the type Siemens TCA 105 or TCA 355B, which have

830 the advantage of not being sensitive to surrounding light or dirt. On the other hand, they have the disadvantage of being sensitive to the gap between their measurement face and the toothed wheel, thereby creating a disturbance on the signal which, if it is controlled, can give good results.

835

One can also want to replace the detection on the teeth of the same trays (7) (8) (9) by an encoder wheel or other means as the state of the art offers them.

840 The principle of detection also applies to the rear gears on one of which can be added an optical detector.

Depending on the volume of the production series of the invention, it is possible to use different production technologies,

845 is programmed using memories, or melted in the silicon, or using fuzzy logic. The calculation method can also be performed from analog circuits, or a combination of digital and analog circuits.

850

Claims

CLAIMS:

1. A method for calculating the instantaneous engine torque applied to a bicycle whose crankset is equipped with a

855 measurement of movement and calculation of its angular velocity and acceleration, and a device for measuring the rotational movement of a wheel, method in which the detection of the local minimum of the angular acceleration of the pedal and memorization from the value of this minimum to

860 inside each half-cycle or several half-cycles of rotation of the crankset allows on the one hand to discriminate the contribution of all the external forces to the assembly formed by the bicycle and its driver from that of the engine torque, and on the other hand to quantify it in order to calculate the

865 instantaneous, average, or peak power supplied by the cyclist when there is direct and continuous transmission of pedal movement to the driving wheel.

2. Method 1 in which the current report of

870 reduction of the chain transmission, that is the ratio of the number of teeth of the plate leading to that of the driven pinion, is obtained either by counting the number of pulses received from the device for measuring the movement of the pedal during one or more complete rotations equipped wheel

875 of the device for measuring the rotational movement, or directly the processing of signals emitted by the derailleur control devices or the derailleurs themselves, for calculating torque and instantaneous power output.

880 3. A method of detecting the rotational movement of a plate directly using the profile of its toothing, ie all shapes, surfaces and volumes necessary for the smooth meshing of the chain in order to transmit the motor force, to influence the path of a beam of

885 photons emitted by an optoelectronic emitter whose periodic and sequential control consists on the one hand of measuring by a photosensitive receiver, protected from ambient illumination by one or more brushes producing a protective screen between the sensor and the plate, the value surrounding illumination

890 alone and memorize it, and secondly to compare this stored value with the current value measured by the same photosensitive receiver when the optoelectronic transmitter is put into operation, to determine the presence or absence of a tooth in the path of the photon beam emitted by an optoelectronic emitter 895 and storing the state until the next detection sequence.

4. The method 3, in which the measurement of the stored or non-memorized ambient illumination is carried out by a

900 second photosensitive receiver independent of the first.

5. The method 3 in which the optical sensor is transmissive type, that is to say that the presence of a tooth in the light beam emitted by the optoelectronic transmitter

905 interrupts photon reception by the photodetector.

6. Method 3 in which the optical sensor is of the reflective type, ie the absence of a tooth in the light beam emitted by the optoelectronic emitter

910 interrupts photon reception by the photodetector.

7. The method 3 in which the control frequency of the optoelectronic transmitter is not constant but dependent on the calculated prediction of the probable instant

915 appearance or disappearance of a plateau tooth.

8. A method for calculating the energy resources consumed by the user of a bicycle equipped with a device able to calculate the instantaneous power supplied and its value

920 average, and consisting on the one hand to compare the amplitude of the instantaneous power supplied or its average value to pre-defined thresholds in advance, and secondly to quantify the duration of the excursion of the signal to the above these thresholds, in order to account for consumption in each of the three

925 alaactic anaerobic, anaerobic lactic or aerobic energy sectors, with the aim of generating visual and acoustic signals for use by the cyclist.

9. The method 8 in which the values of the resources of the 930 three sectors starting from a path are initialized, the counter of the lactic anaerobic die recharged during the course of the journey according to the energy expenditure profile of said embodiment, this according to the physiological data and recovery capacity specific to the 935 cyclist, in order to provide at the end of cumulative information on total energy expenditure in each sector.

10.A method according to 8 managing the information of a device 940 measuring cardiovascular activity to display the evolution of the minimum and maximum of the heart rate in correspondence with the activity in each sector.

11.A device mounted on the frame of the measuring bicycle 945 direct and without contact of the rotational movement of a plate using its toothing and consisting of:

an optical pair with a focused light-emitting transceiver with a light-emitting diode and a phototransistor, of the genus transmissive fork or block

950 reflective,

a fast analogue comparator comparing the signal of the phototransistor with a value which is a function of the level of ambient illumination of the sensor,

an adaptation of the gain of the phototransistor as a function of 955 the ambient illumination,

a status memory of the output of the analog comparator,

a fast clock controlling in sequence the emission of photons by the light-emitting diode and driving with a

960 leaves a memory follower device of the level of ambient illumination and secondly the state storage of the output of the comparator, which is a direct representation of the presence or absence of a tooth.

965 12.A device, autonomous and comprising a central unit, mounted on a bicycle and making it possible to calculate the speed and the angular acceleration of the crankset by means of a device for measuring the movement of a plate, which combined with a device for calculating the gear ratio

970 plate / pinion to calculate, thanks to the detection of the passage of the angular acceleration of the pedal by a local minimum during the rotation, to graphically display, to emit a sound signal, to record and to restore the instantaneous torque, the instantaneous power

975 and their average values, maximum maximorum, and comprising: a central unit with acquisition, calculation, communication, memory dating and memory processor, a multitasking real-time monitor, a mixed display unit matrix and digital, retro

980 illuminated digital processor placed under the control of the central unit,

an acoustic signal emitter,

a power management unit for isolating the supply of the sensors and the display,

985 -a user interface by means of micro-contacts, -a serial link interface for communication with global positioning equipment (GPS) or a non-embedded computer, -a battery or accumulator power supply

990 rechargeable,

-a solar panel capable of powering the system and recharging the batteries,

a mechanical protection of the electronic equipment against bad weather, dust and shocks,

995 - a removable mounting device on the handlebars of the bicycle,

a beam for connection to the electronic sensors, means for detecting the angular rotation of the pedal and fixing it on the frame of the bicycle, its attachment and its mechanical protection,

a means for detecting the angular rotation of the plate connected to the chain and its attachment to the frame of the bicycle, its attachment and mechanical protection, a sensor for angular rotation of the wheel. 1005

13.A device according to 12 in which the comparison of the amplitude of the instantaneous power or the average power supplied to physiological thresholds makes it possible to determine the operating path of the ATP resources of the cyclist, either anaerobic alactic, or lactic anaerobic, or finally aerobic, to display it, to emit sound or optical signals, to record and combine this information with the position of the cyclist on a path.

1015

14.The implementation of the algorithm as described in 1 proceeds from a complete or partial digital programming used by a central unit equipped with one or more microprocessor or microcontoller or signal processor

1020 digital or in logic or fuzzy logic on one or more chips.

15.The implementation of the algorithm as described in 1 made completely or partially from components

1025 active and passive electronic discrete, integrated or hybrid, such as a memory follower device, analog multiplier, analog differentiator, summing operational amplifier, comparator, and analog-digital converters for operation on a unit of

1030 treatment or display.

16.The implementation of an algorithm as described in 1 and carried out by any technical combination of manufacturing solution as described in 14 and 15.

1035

17. an assistant assisting with the management of muscular resources incorporating:

a calculation algorithm as described in 1, a calculation method as described in 8,

1040 -an electronic equipment as described in 12,

-Three counters operating time in the three power ranges corresponding to the anaerobic alactic, lactic and aerobic anaerobic sectors, -a display of information from a system

1045 independent measuring of cardiovascular activity,

management of the current position of the bicycle on a course determined in advance, giving the cyclist an indication of the moment of timely initiation and the amplitude of his effort.

1050

18.A device according to 17 wherein the detection of rotational movement of the pedal is carried out using a device such as 11.

19. A device according to 17 wherein the detection of rotational movement of the pedal is carried out using a device with multiple singularities, optical, magnetic, inductive, capacitive, reluctant, added to the pedal or the trays.