DE4227586A1 - Ergometer, e.g. for training sports cyclists, - measures deformations of pedals, handlebars and seat stem independently in orthogonal directions - Google Patents

Abstract

The ergometer separately measures all four possible elastic deformations which can occur in a pedal lever, i.e. bending in the rotation direction, bending perpendicular to this direction, extension along the lever and torsion about the lever. The direction and amplitude of the force applied by the rider to the pedal are derived using Hook's equation or elasticity theory. The force is measured at many different angular positions of the pedal. One revolution is divided into a large number of small angle intervals, between which the force is quantised and the time recorded. The forces acting on the steering mechanism and saddle are determined from the elastic deformations of the handlebar and saddle stem respectively in three orthogonal directions. USE/ADVANTAGE - For training with sports equipment, e.g. cycle. Enables optimal motions to be determined and taught to sportsman.

Description

The invention relates to a device, to be referred to as an ergometer, the finding and training of the optimal movement serves, which by the construction of the sports equipment, here by a bicycle is predetermined, by recording constructive and destructive parts of the force, that the cyclist releases on the bike.

A device of the same type is known from PS 37 22 728. In this patent a device is described, which in a particular Embodiment for measuring the attack on a bicycle crank Power at which the torque transmission from the crank to the chainring takes place, the mechanical quantities acting on the crank, Torque and angular velocity, converted into electrical signals and transferred to the frame by induction from the moving crank and there are fed to an evaluation device.

However, the power measurement described in PS 37 22 728 knows the following Defects that counteract economic use include:

First of all, the high design effort, which is due to the design and integration of separate deformation elements, which is clearly represented by FIGS. 2-4 of this patent specification, entails enormous costs, which are increased in particular by equipping the bicycle used for power measurement with this crank construction , ie must be rebuilt.

Second, induction signal transmission is relatively low  Frequencies too. Here the limitation is less in technology than in To look for provisions of the Telecommunications Act, because at higher frequencies the transmission coil acts as an antenna and thus emits an interference signal. A low frequency means, as in the theory below is shown, low resolution of the measured variable and long integration times for a measurement.

Third, the angular velocity of the pedal crank is derived from the cadence determined, which means that the angular velocity over averages one full turn of the pedal crank and thus also the calculated quantities work and performance.

Fourth, an auxiliary energy is required, which is moved along with the bottom bracket got to. As in the case described here means a dry cell or a battery but that by checking or replacing this auxiliary energy at the Pedal crank is constantly to provide sufficient resources, and that because The interchangeability of this auxiliary energy requires further constructive measures are to protect the device against water and dirt.

Furthermore, laid-open specification DE 38 13 681 A1 describes an ergometer, especially for bicycles or other devices where a Rotational or pivoting movement work can be initiated. Here are strain gauges applied to the frame or the bottom bracket, which serve the purpose of to determine the force exerted on the crank or the chain force.

The disadvantages here are partially analogous to the above. Especially here, too, no exact quantization of the forces with regard to direction and time made.

Furthermore, the published patent application DE 38 13 792 A1 describes a device for measuring and evaluating the performance data of a cyclist, which are exclusively used to determine and display the round kick by evaluating serves the uniformity of the angular velocity. Here is just the Considered angular movement of the crank, but not like the cyclist Brings crank movement d. H. how he unfolded his power on that Wheel designed.

Furthermore, there is an ergometer in European patent EP 0 422 325 A1 specified. However, this is a stationary device, at which generates the force opposite to the cyclist through a braking system  becomes. Here the force is recorded at different angles of the pedal lever, which, due to the design, is only stationary and not separate for both pedals is possible. This ergometer is representative of everyone else called stationary.

Ultimately, in utility model application G 83 30 952.7 by Fig. 2nd reproduced a lever on which strain gauges are applied, but which is distinguished by special Form design and the measurement of torque in one limited angular range is used, ie with the subject matter of the invention presented here is also not in conflict.

The object of the present invention is to overcome the disadvantages listed above and to fix restrictions and in particular that caused by the training device predetermined optimal sequence of movements, here with a bicycle find and train what is constructive and through the separate capture destructive parts of the force released by the cyclist on the bike can be realized is. This is intended in particular in real time and under the invention real training conditions are made possible.

This object is achieved in that after detailed Analysis of the relevant elastic deformations on the pedal lever suitable arrangement of strain gauges on the pedal lever, selective and be recorded independently of each other.

Although a claim is listed in the publication PS 37 22 728 that a Area of the pedal crank itself is designed as a bending element on which the Strain gauges are applied, however, no further details and provided information on how to design this bending element and how the application should be carried out, or not what results can deliver such an arrangement.

The starting point of the invention is a law of elasticity theory: "Volume elasticity and shape elasticity are two different from each other mutually non-influencing effects of the atomic binding forces. " With this information and the associated mathematical formalism the elasticity ratios for combined volume-based and shape-elastic deformations such as bending, elongation or derive torsion.

In view of the small forces that act on the pedal lever, only slight deformations can be expected. As a result, Hooke's law becomes valid (deformations are first order to the force), and it is possible to apply so-called small-angle approximations. B., as shown in FIG. 2b on a rod TS twisted by the torsional moment T, for small contact angles SW means that cos (SW) ≈1 and thus has almost no influence on strain gauges applied in the longitudinal direction. Based on the resultant and, in particular, experimentally confirmed and verified facts that four elastic deformations are relevant and independent of each other within the framework of the forces to be expected from a pedal lever,

• - Bend in the direction of rotation ( Fig. 1a),
• - Bend perpendicular to it, ie in the direction of the axis of rotation ( Fig. 1b),
• - Elongation in the longitudinal direction of the pedal lever ( Fig. 1c),
• Torsion about the longitudinal direction of the pedal lever ( FIG. 1d),

and can be recorded separately and independently of one another, is based on Subject of the invention.

Since the individual deformations on the pedal lever can be regarded as independent, they can also be analyzed separately. The result of a bend ( Fig. 1a) is shown here by way of example: the force F causes a positive D on the upper side of the bending rod and a negative expansion S (compression) on the lower side. In between is the neutral fiber NF, which maintains its length L (free length of the rod).

By deriving one obtains from the curvature

where R is the Radius of curvature at point s and E is the modulus of elasticity, for the shape of the loaded bending rod:

The bending arrow a is obtained from

In all formulas, J _{A is} the area moment of inertia of the rod or pedal lever defined by J _A = ∫ _A dA r² on the cross-sectional area, over the edge of which the strain gauges are applied.

For the elongation ε, which is positive on the top and on the bottom has a negative sign, results in the application area under consideration  (for relatively short strain gauges)

( Fig. 3a), from which, by multiplying by the k-factor of the strain gage and inserting it into the bridge equation, the bridge diagonal voltage at the terminals 1 and 4 of the Wheatstone bridge ( Fig. 3c) follows. H is the distance between the strain gauge application surfaces and the neutral fiber. In the opposite direction, a bridge diagonal tension can be clearly assigned the force responsible for the bending.

In order to selectively record the bending of the pedal lever in the direction of rotation ( Fig. 1a), it is most sensible to apply the strain gauges to the top and bottom of the pedal lever, preferably in the section designated here as the favorable application area GAB ( Fig. 3a, b) , because the greatest deformation is to be expected in this area due to the large leverage between the strain gauge and the pedal axis PA.

With two DMS Fig. 3b applied on opposite sides of the pedal lever, a bending by the bending moment M _b causes the DMS1 and an ε to be stretched at the _top and the DMS2 to _be compressed by the same amount ε _{at the bottom} . A superimposed normal strain, on the other hand, stretches both strain gages with the same sign by an ε _n . If you put this into the bridge equation of the bridge connected according to (Tab. 1), the signals of the bend are added by reversing the sign of the signal of a strain gauge, while the signals of the normal expansion cancel each other out. Normal strains superimposed on the bend are therefore not included.

The same applies to the application according to Fig. 4 and Tab. 2, which selectively detects a bend in the direction of the axis of rotation ( Fig. 1b).

On the other hand, so that the bending signals compensate, and only the normal strain is detected here go in a switched according to Tab. 3 bridge the strains of the same sign a, which applied also to FIG. 3a and FIG. 4 DMS applies. This situation is shown again in summary for normal strains in FIG. 5, with the special feature that the favorable application area takes up almost the entire lever here, since the normal stretch extends uniformly over the entire lever length.

For bends transversely to the direction of rotation (Fig. 1b) may be in an application according to Fig. 3a and Fig. 3b, left transmit the above mentioned small angle approximation, that is cross-bends are not detected. For a full bridge application, for example, according to FIG. 3b on the right, the situation is more complicated. Here are z. B. the two DMS1 and 2 upset (negative ε) and the two DMS1 'and 2' stretched (positive ε). By arranging the bridge members accordingly, the transverse strain signal can be compensated in addition to the normal strain signal, so that even a full bridge arrangement remains selective for only one bending direction.

In principle, it would also be possible to use simple quarter-bridge circuits and to differentiate the values obtained with them arithmetically, but this is of no further interest because of the potential error rate of this method. It should also be noted that with pedal levers that taper to the top and bottom, only the application according to FIG. 3b on the left makes sense.

The torsion is usually determined using so-called 90 ° rosettes or by means of linear strain gauges applied on all sides, rotated 45 ° ( Fig. 6).

Furthermore, instead of many single strain gauges, so-called multiple strain gauges can be used, which combine the strain gauges to be applied for the various deformations. For easier handling and application, the strain gauges can also be applied to supports, so-called application aids AH. So z. B. equip a pedal lever made of steel quickly and easily by spot welding with a metal strip as a strain gauge-bearing application aid. Other materials can e.g. B. by gluing as application aid AH ( Fig. 7).

The fact that the attachment can also be carried out by means of clamping elements KE ( FIG. 8) is particularly of great interest that any bicycle can also be retrofitted by laymen with such applied strain gage carriers, which may already have been contacted and encapsulated with a covering , which is why special chainrings or pedal crank constructions become obsolete. The application would not be restricted to a small group of experts. In the case of clamped strain gauge applications, the above-mentioned formula for the stretch is no longer applicable, since the bending in the area between the clamps is transformed into a normal strain of the strain gauge carrier, but this has no significant effect on the accuracy that can be achieved.

The voltage, which is supplied by the Wheatstone bridge and is proportional to the force, is further processed directly by electronics which are moved on the pedal crank. These electronics, including the supply for the strain gauge bridges ( Fig. 3c connections 2 and 3 ) are supplied by inductive means. It is implemented by a rotatable transformer arrangement, which consists of a pair of opposing coils on the front side, of which a T1, resting rigidly on the frame TL, flows through an alternating current (f <1 kHz) provided by a central supply, and thus in the other T2 the pedal crank PK also induced a voltage ( FIG. 10). This voltage is rectified and screened by a capacitor.

The electronics are e.g. B. from an extremely low power, through Bridge diagonal voltage directly controlled quartz oscillator circuit that consists mainly of field effect transistors and also at very low operating voltages works safely, but will not be presented here needs. If it is implemented in SMD technology, it only takes approximately per channel the area of a 1 DM coin. With a custom chip even in a single IC, so without problems with the pedal crank accommodate.

The transmission of the data from the rotating pedal crank to the frame is solved in a particularly advantageous manner by a rotatable optocoupler. It consists of two components that face each other, one of which is also moved on the pedal crank PK, while the other is rigidly attached to the frame TL ( FIG. 10). The component moving on the pedal crank, the transmitting part ST, consists of a light ring LR, which, for. B. can be designed as a diffuser and reflector ring RE and the front of one or more light transmitters, injected into the ring LR distributed signal over the entire ring. FIG. 11a shows z. B. the front side of a transmitting part, the light ring is illuminated by a light-emitting diode LED, with a light intensity proportional to the signal to be transmitted.

By pulse operation of the transmitter diode LED, e.g. B. with the help of a driver capacitor, the charged slowly and evenly in the pause and its stored energy abruptly to the LED when there is an impulse outputs, it is possible to use the inductive power supply on the pedal crank low and even load, and yet extremely high luminance to achieve, which is why an LED was sufficient in the experimental setup to  Illuminate the illuminated ring completely.

The component rigidly attached to the frame, the receiver part ET, consists of one or an arrangement of light receivers LE, e.g. B. photodiodes formed. It must be arranged in such a way that during a complete revolution of the transmitting part a part that strikes the light intensity emitted by the light transmitter hits a receiver, that is, the transmission never stops ( FIG. 11b).

If infrared light IR is used for transmission, a simple IR filters are blocked in front of the receiver, disturbing extraneous light, so that it is not absolutely necessary for the gap between the transmitting and receiving parts isolate from light. This is therefore of practical application Advantage because the two parts of the optocoupler, but also supply coil and electronics can be potted hermetically, in connection with which with encapsulated strain gage carriers a completely insensitive to water and dirt Structure is given. Because the transmission is accomplished by light is even at the highest frequencies of the oscillator (e.g. several 10 MHz) the problem of a jammer eliminated.

Several of these transmitter and receiver components are centered around each other arranged so that a corresponding number of channels transferred from the rotating part to a resting one.

By partially covering the transmitter ring and correspondingly arranging reception windows with separate receivers, this optocoupler can simultaneously serve as an angle encoder, which is shown in FIG. 12 for an impulse-giving and in FIG. 13 for a code-giving optocoupler. The transmission and reception windows are arranged so that at least one receiver always sees the transmitter signal, i.e. the transmission never stops. After the information of the angular position has been obtained, the signals of the receivers are collected at one point and the received signal thus obtained is passed on.

The frequency signal of the _VCO f _vco = f₀ + Δf, which is now electrically available on the frame and modulated with the force acting on the pedal, can now be most easily _correlated with a second frequency corresponding to the center frequency f₀ of the VCO. After appropriate preparation, this can be done either additively or multiplicatively. With the help of the addition theorems for angular functions it is shown:

for addition and

for multiplication, where A is the amplitude and ω = 2πf the angular frequency of a signal. If you take the high frequency vibration term z. B. through a low-pass filter, you get a signal that depends only on Δω or only on ΔF, that is, directly on the pedal load and is to be referred to below as a load signal. This shows the advantage of multiplicative correlation. On the one hand, the slow-period term, the signal term, has twice the frequency, which means that half the resolution is _wasted with an addition, and on the other hand, the two amplitudes A₀ and A _{vco of} the signals do not have to match as absolutely as it does when adding the Case must be. Multiplication is very easy to implement with an integrated analog multiplier module.

With the simple trick of rectifying the load signal before triggering, So flipping up the negative half waves brings another one Resolution improvement by a factor of 2.

The resulting resolving power will be explained here using the example of the test model set up to demonstrate functionality. The center frequency of the VCO was 10 MHz and the maximum frequency shift was designed for 10% with a pedal lever load of 100 kg (F _max = 1000 N) in the direction of rotation ( FIG. 1a). If one assumes that the angular velocity of the pedal crank will hardly be above 5 revolutions per second, and that the force at 100 angular positions of the pedal crank is to be recorded (scanned), this results in a pulse frequency of f _T = 500 Hz Max. Frequency shift Δf of the VCO and thus the load signal is 1 MHz. By rectifying and introducing factor 2 this results in 2 MHz, and thus a possible resolution of the force on the pedal lever to ΔF = (500/2 · 10⁶) · F _max = 0.25 N, which corresponds to a weight of 25 g. On a counter with the gate time T _Tor = 1 / f _T = 2 ms, this signal gives the force on the pedal directly in 0.25 N units.

With two narrow-band high-pass filters and a downstream comparator or a simple PLL (phase locked loop) circuit  still detect the sign of the frequency shift and thus the above Resolution for both directions, i.e. H. for compressive and tensile forces alike to reach.

The torque M applied to the crank via this pedal lever then follows from the simple multiplication of the measured force by the pedal lever length L. By the sign of the force is also the sign of the Given torque. The torque M in turn with the angular interval multiplied between two measurements gives the delivered in this interval Job. If you sum these intervals z. B. over a full crank revolution or a period of time, that gives that during a crank revolution or work given to the bike during the period.

With the additional time recorded, further, very diverse analyzes and Evaluations such as B. Performance, various average, maximum and minimum values etc. can be calculated and displayed.

A great advantage is that both pedal levers can be equipped separately with the above-mentioned measuring and transmission devices, which makes it possible to record the power development for the right and left leg separately. This reveals differences in performance, movement or other symmetry, the elimination of which can then be specifically trained ( FIG. 17). The total work, performance, etc. follows by adding the right and left side.

The measured variables such as force, torque, power etc. can be represented particularly favorably in a polar diagram. A good cyclist will always try to transfer as much power as possible to the pedals, which he does by using not only the angle range between 0 ° and 180 ° by pedaling, but also in the range between 180 ° and 360 ° " pulls ". For him, the polar diagram will assume approximately the form shown in FIG. 15, while a recreational driver probably does not "pull" and simply "stands" on the pedal in the rear area ( FIG. 16). The negative torque generated, or the negative work, of course, must not be deducted from the energy balance, because the cyclist does not recover any energy. But adding up separately shows how much additional energy is consumed.

The shape of the polar diagram shows the cyclist in particular how well he realizes the "round kick" and can react to it immediately and change his movement sequence ( Fig. 17).

For this it is necessary to use this data in real time on the bike, e.g. B. in an LCD raster display, but what can be easily built and programmed with today's highly integrated computer technology. In such a real-time diagram ( FIG. 15), e.g. B. symbolizes the pedal lever position by a beam ST, similar to the line of sight of an old radar device, at whose position SP the curve is overwritten by the new values.

Of course, time averages can also be represented as a polar diagram, as happened in FIG. 16. The angle EW, which is assigned to the longest radius vector lying on the curve, is the most effective angle of action at which the greatest performance was achieved on average.

It can also, e.g. B. a target performance to be provided before the training. The current, e.g. B. power averaged over the last three crank revolutions can be compared with the predetermined one and the deviation thereof can be output as a display ( FIG. 17). Such target specifications have hitherto been achieved almost exclusively via the driving speed, but as a result, sources of error such as wind and road surface had to be systematically neglected.

The analyzes and evaluations described so far are already possible with a device version that only detects the bending of the pedal lever in the direction of rotation ( FIG. 1a). In order to determine the optimal movement sequence, at least the bend in the direction of the axis of rotation is required ( Fig. 1b), because even these two bends can be used to characterize the force on the pedal lever very well, because two of the four relevant deformations ( Fig. 1a-d) occur together due to the geometry of the laterally arranged pedal on the pedal lever, which can be explained as follows. Is the pedal lever z. B. at top dead center ( Fig. 14: 0 ° position), a vertically downward force on the side pedal causes both a compression (negative expansion) in the longitudinal direction of the lever ( Fig. 1c) and a bend in the direction of the crank axis of rotation ( Fig. 1b). On the other hand, with a 90 ° position, a vertical force causes the pedal lever to be bent in the direction of rotation ( FIG. 1a) and tortured about the longitudinal axis of the lever ( FIG. 1d). Therefore, for the sake of simplicity, only the two bends should be considered first.

The concept of constructive and destructive power is now derived as follows. The only component that is constructive is the force component that causes the bend in the direction of rotation ( FIG. 1a), since only it is converted into forward movement by the torque. The force component, which is responsible for the bend in the direction of the axis of rotation, cannot be mechanically converted into forward movement, but only generates a static counterforce in the pedal lever. A static load does not consume any work in the physical sense, but it does in the physiological one, which can be easily visualized if one z. B. tries to hold a weight with an extended arm for a long time. That is why the latter force is destructive. Due to the separate detection, the information as to how these two components are related to each other during the movement sequence can be displayed in real time and, for example, in real time. B. can be provided very elegantly in a polar diagram.

Finding and training the optimal movement now means to design the movement so that the constructive force share maxi- and destructive force share is minimized. Even if the saved with it, otherwise useless wasted energy compared to the total wasted Work may be small, it may be precisely these reserves that are on the last few meters before the goal are decisive for a victory.

In addition to the bends, the other two deformations are also used for force detection is an even more precise analysis of the movement possible, e.g. B. whether the foot rotates or rolls is carried out, which also consumes unnecessary strength or whether and how the cyclist on the pedals.

In order to optimize not only the movement of the legs, but that of the whole body, the forces on the handlebar and saddle are also taken up as further points of contact for the cyclist with the bicycle. This can also be done by strain gauges, which are applied to the handlebar and seat post ( Fig. 18 and 19), for different directions of force. If the cyclist works a lot with the upper body, such as seesaws in pedal cycle, this can be demonstrated and recorded by the elastic deformations of the same under the changing load, since he is supported or holding on to the handlebar. The same applies to the saddle. In this way, the complete movement of the whole body can be recorded, analyzed and optimized in all details, which creates a fundamental basis for training planning.

Since it is almost impossible and also does not make sense, the full range of possible Reproduce analyzes and evaluations on the bicycle display, could the data stream during the training z. B. record on a magnetic tape. This is possible thanks to the very compact Walkman technology already proven. With the advancing chip development moving forward e.g. B. also semiconductor memory in card form, in applicable dimensions, with which the collected data then also for further analysis on one stationary computers can be transferred. In particular, with the collected data over a longer period of training and also the progress made is closely monitored and for training planning be used.

To ensure high accuracy and quality of the measured data, it is essential to calibrate the device. In particular it is very difficult with clamped strain gauge carriers on different pedal levers, to record all possible free parameters and in an adjustment circuit to compensate. Such a circuit is, however, technical under the following easily implementable requirements not necessary at all.

The strain gauges must be self-compensating for their carrier material and the pedal lever be d. i.e., thermal expansion in the carrier and pedal and change in resistance of the strain gauge with the temperature cancel each other out. The center frequency of the VCO must not have any significant temperature drift. The frequency shift need not necessarily be linear with the signal, but must not change with the temperature either. The last two conditions can be by quartz oscillators and clever insertion of temperature sensitive resistors such as NTC or PTC resistors or additional semiconductors in the oscillator circuits.

The calibration itself is done by software after the device is attached to the bike and its pedal crank. The program of the a balancing polynomial, the most elegant a Chebyshev polynomial or an assignment table provided that one Signal assigns exactly the right size to the force. This polynomial can in principle as the inverse function of everyone, through measurement and transmission  resulting distortions and errors can be understood. The benefits for this Type of calibration on the bike are that different E-modules and Area moments of inertia of the pedal lever recorded and included in the measurement which means that everyone is individually calibrated and manufacturing tolerances, Material inhomogeneity and other differences are not significant fall.

The calibration itself can be implemented in the following way. The pedal crank is successively defined in the different directions Forces, e.g. B. by attaching weights. The weights can either be specified by the computer or must be entered become. This specifies base points and the respective one Signal measured directly. The calculated polynomial coefficients or table data can then be saved in an EE-PROM, in which they too do not get lost if voltage is lost.

The device could also be calibrated automatically by an auxiliary device, which generates a defined load on the pedal lever and the value, type and Direction of the load as data via an interface to the computer passes on.  

Table 1: Bridge circuit for bending in the direction of rotation ( Fig. 1a)

Table 2: Bridge circuit for bending in the direction of the axis of rotation ( Fig. 1b)

Table 3: Bridge circuit for normal expansion in the longitudinal axis of the lever ( Fig. 1c), the dashed strain gauges are rotated 90 ° to the uncoated

General information about the tables:

R _E are the supplementary resistors in the Wheatstone bridge.
ν is the so-called transverse expansion number.
Bridge circuits that would result from permutation of connections 1 ↔ 4 and 2 ↔ 3 are not listed separately, since permutation only changes the sign of the voltages, but leaves the function of the bridge unchanged.

Claims (14)

1. The invention relates to a device to be referred to in its type as an ergometer, which serves to find and train the optimal movement, which is determined by the construction of the sports equipment, here by a bicycle, by detecting constructive and destructive proportions of force that the cyclist releases on the bike, characterized in that one to all four possible elastic deformations that are relevant to the pedal lever,

• - Bend in the direction of rotation ( Fig. 1a),
• - Bend perpendicular to it, ie in the direction of the axis of rotation ( Fig. 1b),
• - Elongation in the longitudinal direction of the pedal lever ( Fig. 1c),
• Torsion about the longitudinal direction of the pedal lever ( FIG. 1d),

are recorded separately and independently of one another and, based on Hooke's law or elasticity theory, enable an exact conclusion to be drawn about the direction and the amount of force exerted by the cyclist on the pedal,
that the determination of this force takes place at a large number of different angular positions of the pedal crank, which means in particular that one revolution of the pedal crank is divided into a large number of small angular intervals, between each of which the force is quantized,
that the force acting on the handlebar is detected by the elastic deformation of the handlebar or the steering axle in the three possible, mutually linearly independent room seals,
that the force acting on the saddle is detected by the elastic deformation of the saddle rod in the three possible, linearly independent spatial directions and
that the time is also recorded for each quantization of the forces. 2. Device according to claim 1, characterized in that
that almost all commercially available pedal levers can be used for signal generation without any design changes,
that the detection of the bending of the pedal lever in the direction of rotation ( Fig. 1a) by strain gauges (DMS), whose centers (focal points) lie in the plane or in full bridge application at the same distance from the plane, which is due to the neutral fiber of the transverse bend ( Fig. 1b ) is clamped in the unloaded state and which are connected in a Wheatstone bridge so that the signals of the other deformations ( Fig. 1b-d) compensate ( Fig. 3 and Tab. 1),
that the detection of the bending of the pedal lever in the direction of the axis of rotation ( Fig. 1b) is carried out by strain gauges, the centers (centers of gravity) of which are in the plane or in the case of full bridge application at the same distance from the plane which are caused by the neutral fiber of the bend in the direction of rotation ( Fig. 1a) is clamped in the unloaded state and which are connected in a Wheatstone bridge in such a way that the signals of the other deformations ( FIGS. 1a, c, d) compensate (FIGS . 4, 3b, 3c and Tab. 2),
that the detection of the normal extension of the pedal lever in the direction of the longitudinal axis of the lever ( Fig. 1c) is carried out by strain gauges, which can be applied on all sides, but always in pairs opposite each other and which are connected in the Wheatstone bridge so that the signals of the other deformations ( Fig. 1a, b, d) compensate ( Fig. 5, 4 or 3 without 3b right and Tab. 3),
that the detection of the torsion of the pedal lever about the direction of the longitudinal axis of the pedal lever ( Fig. 1d) is carried out by special torsion rosettes (90 ° rosettes) or by 45 ° inclined linear strain gauges ( Fig. 6) and interconnected in the Wheatstone bridge are that the other deformations ( Fig. 1a-c) compensate each other,
that the strain gauges do not necessarily have to be applied directly to the pedal lever, but can be applied to so-called application aids and carriers that are easier to handle or more robust,
that these application aids are attached to the pedal lever by means of suitable clamping elements (FIGS . 9a, b) which may be adapted to the respective pedal lever ( FIG. 8) or
that these application aids are simply glued to the pedal lever ( Fig. 7). 3. Device according to claim 1 and 2, characterized in that
that the bridge diagonal voltage caused by the load on the pedal lever of the Wheatstone bridge circuit built up or supplemented by the strain gauges directly detunes or controls a voltage-controlled oscillator (VCO) which is moved on the pedal crank and thus generates a frequency shift proportional to the measurement signal,
that the strain gauges themselves can be part of the oscillator circuit and
that the modulated frequency generated by the VCO is optically transmitted from the moving pedal crank to the frame by a rotatable optocoupler. 4. The device according to claim 1, characterized in that the supply of the electronic components located on the pedal crank, takes place inductively by a rotatable transform gate arrangement ( Fig. 10) from the frame TL to the moving pedal crank PK. 5. The device according to claim 1 and 3, characterized in that
that the rotatable optocoupler consists of two components that face each other, one of which is also moved on the pedal crank PK, while the other is rigidly attached to the frame TL ( FIG. 10),
that the moving component on the pedal crank, the transmitting part ST, from a light ring LR, z. B. diffuser or reflector ring, which consists of one or more light transmitters LS, z. B. LEDs, with a proportional to the signal to be transmitted luminous intensity is illuminated ( Fig. 11a),
that the rigidly attached to the frame component, the receiver part ET, from one or an arrangement of light receivers LE, z. B. photodiodes, such that even with a complete revolution of the transmitter part always a part that strikes the light intensity emitted by the light transmitter on a receiver ( Fig. 11b),
that the rotatable optocoupler can have several separate channels and
that the rotatable optocoupler can also be constructed as an angle encoder. 6. Device according to claim 1, 3 and 5, characterized in
that the rotatable optocoupler generates a pulse for each angular step for each angular step by suitable segmentation or, in some cases, covering the light ring in the transmission part and by suitably arranging reception windows with the light receivers in the reception part ( FIG. 12) or
that the rotatable optocoupler by suitable segmentation or covering the light ring in places in the transmitting part and by suitably arranging receiving windows with the light receivers in the receiving part a clearly assigned to the angular position, for. B. binary coded signal generated ( Fig. 13). 7. The device according to claim 5 and 6, characterized, that the use of the optocoupler is not limited to the bicycle, but is generally applicable where signals from a rotating Part must be transferred to a dormant. 8. Device according to one of the preceding claims, characterized, that the measurement signal acquisition and forwarding for the right and the left Pedal levers can be executed separately, i.e. two independent ones Signal sets are obtained. 9. The device according to claim 1, 5 and 6, characterized in that
that the absolute angular position of the pedal crank is detected by an angle-giving optocoupler or
that the absolute angular position of the pedal crank z. B. is detected with the aid of a slit or reflex disk light barrier arrangement. 10. The device according to claim 1, characterized in that the occurring on the steering rod, steering axle and seat post, caused by the forces acting deformations are detected by strain gauges, the z. B. all around the handlebar and seat post ( Fig. 18 and 19) are applied. 11. The device according to claim 1 to 5, characterized in
that the frequency generated by the VCO and transmitted to the frame by the optocoupler is correlated with a second, constant and the center frequency of the VCO corresponding frequency, ie added or multiplied, and
that after filtering out the center frequency of the oscillator, the envelope thus obtained is used by subsequent triggering directly as an input signal for a counter with defined technology. 12. Device according to one of the preceding claims, characterized in that
that the device shown in the context of the invention only needs to be calibrated after the respective assembly on the bicycle or on the pedal crank,
that this calibration either by hand by successively loading the pedal lever with defined forces, e.g. B. by attaching weights, or
that this calibration of the measuring system is carried out by an automatically operating calibration device that generates a defined load on the pedal lever and transmits the value, type and direction of the load as data and
that the calibration of this measuring system is done by software, e.g. B. by calculating the coefficients of a compensating polynomial or by creating an assignment table that assigns the correct force to the measuring signal present. 13. Device according to one of the preceding claims, characterized in that
that the complete movement sequence of the cyclist as well as his ergometric performance data can be reconstructed and ascertained from the data obtained,
that it can be analyzed on the basis of this data which part of the rider on the bicycle, in particular the force exerted on the pedals, is to be expected constructively, that is to say for the optimal movement sequence, and which part is destructive, that is to say cannot be implemented for locomotion, because this only results in static Opposing forces are generated
that this data can be used to analyze whether the driver is carrying out unnecessary energy-wasting movements,
that these evaluations take place in real time in a computer carried on the bike and thus the deviations from the optimal movement sequence can be displayed immediately,
that these data are presented in the form of polar diagrams ( Fig. 15-17) and
that a target performance can be specified and the deviation from this target performance can be represented ( FIG. 17).