DD286055A5 - METHOD AND ARRANGEMENT FOR REGULATING THE DRIVING AND / OR BRAKING POWER OF THE DRIVING MOTORS OF A LOW-LOW TRANSMISSION VEHICLE AT THE FRONT END OF THE RAEDER - Google Patents

Abstract

The invention relates to a method and an arrangement for controlling the drive and / or braking force of the traction motors of a traction axle-less traction vehicle at the Kraftschluszgrenze the wheels. It is about a method for controlling the drive and / or braking force of the traction motors of a traction-axle traction vehicle at the power limit of the wheels. In this case, the transition to the unstable slip region is to be determined and the wheelset then be returned to the stable slip region by reducing the drive or braking force again above the force minimum point. In order to achieve a close course of the wheel slip in all operating conditions, which is close to the maximum force, it is proposed that the time of termination of the reduction of the driving force of the engine should be determined by the falling tendency of the pulling or braking force actually transmitted to the rails is detected by the real effective on the rails force from the drive or braking force of the engine and the wheelset mass multiplied multiplied by the Radsatzbeschleunigung, formed from the 1st time derivative and fed this as a trend signal with the corresponding decreasing tendency polarity a switching means becomes. Fig. 1 {control; Drive and / or braking force; Traction motor, running axleless; Train; Kraftschluszgrenze; Slip region; Tensile or braking force; wheel set}

Description

- 1 - Berlin, January 23, 1990 73 048/13

Method and arrangement for controlling the drive and / or braking force of the traction motors of a traction-axle traction vehicle at the frictional limit of the wheels

Field of application of the invention

The invention initially relates to a method for controlling the drive and / or braking force of the traction motors of a traction-axle traction vehicle at the frictional limit of the wheels, as defined in more detail in the preamble of claim 1.

Characteristics of the known state ») of technology

Such a method is already known from DE-PS 34 07 309. In this method, a fairly accurate adjustment of the operating parameters is required to keep the deviations from the maximum frictional in limits. In particular, it is difficult to adapt the parameters to achieve optimal behavior to the different operating conditions.

Object of the invention

The aim of the invention is to largely avoid the aforementioned disadvantages.

Explanation of the essence of the invention

The invention »is the object of a method and an arrangement for controlling the drive and / or brushless

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to improve the traction motors of a runnerless traction unit at the frictional limit of the wheels and to make it more tolerant and to achieve as close as possible to the traction maximum course dos Radschlupfes in all operating conditions.

According to the invention, this object is achieved in that the respective time of termination of the reduction of the drive or braking force of the motor (Fm ₀ *.) From the falling tendency of the train or braking force actually transmitted to the rails (F ₂ F ") is detected in which the real effective on the rails force (F ₂ or F _ß ) at the wheel contact point from the drive or braking force of the engine (F _Mot ) and the wheelset mass ( ^m o _a Hsatz) multiplizi" lit the measured Radsatzbeschleunigung ( ⁸ DQd ₉ Qt ₂ ) bb.echnet, formed from this value in a differentiator, the first time derivative and this as a tendency signal with the corresponding tendency of a falling tendency polarity (+ or -) is fed to a switching means , which eliminates the reduction of the drive or braking force of the motor (F _Mot ) when a limit value is exceeded.

The arrangement for carrying out the method is characterized in that the output of a first differentiating element, which is provided for the first time derivative of the determined driving or braking force, is applied in the falling polarity corresponding to a threshold value switch, the signal for the additional counteracting input to the integrator switches off.

According to another embodiment, it is advantageous that f_ _ot from an axle speed f_ _ot via a second differentiation

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The axle acceleration is determined and this value is fed as a negative quantity - for driving directly and for brakes via an inverter - to a summation point "at which the measured motor torque Md ₁ is applied as a positive value and whose output" at which a calculated traction or braking force (F-, F_) is removable, is connected via the first differentiator and a negation element to the threshold value switch «which is connected to a control switch« via which the signal for the additionally counteracting input to the integrator can be switched off.

According to a further feature, the arrangement is characterized in that the limit value stage removable signal Ii is applied to a first input of an OR gate

2. via an on-delayed timer controls a lying in front of the input to the limit level switch with normally closed contact and

3. on the set input a first timer, is connected, which actuates a second timer another switch, the first or via a 3rd differentiating derived second time derivative of the differential speed via a maximum value selection stage switches to a Schmitt trigger on the Control switch connected to a second input of the OR gate is' ;.

In another advantageous embodiment, the third differentiating element is connected to the output of the differentiating device for the first time derivative of the differential speed via an inverter.

In addition, it has proved to be advantageous that the

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-ΑΙ. Timer off delay works and that soin output connected to a switch-on delayed timer and the reset input is connected via an inverter to the output of the OR gate.

The claim 2 refers to a special embodiment with an integrator as a pseudo-axis, as well as the DE-PS 34 07 309 is based. For such an arrangement, the method according to the characterizing features of claim 2 is developed.

The invention can be applied to all traction motors whose motors are operated with torque or current control. The prerequisite for this is that the engine control is responsive, so that the delay times occurring in torque changes remain sufficiently short compared to the timing of spin approaches.

embodiments

Based on a schematic embodiment, the invention will be explained in more detail below. Show it:

1 shows a block diagram for the control of a drive axle with a three-phase rectified motor driven by a weekly rectifier;

Fig. 2: Traction curves over the wheel slip.

In Fig. 1, 1 denotes an inverter which feeds a three-phase traction motor 2. The axle speed is z. B. from a tachometer machine 3 (or a rotary encoder with evaluator) detected. To an input 4 is the one in the

setpoint control for the slip frequency f _s ,, of the motor derived from the torque setpoint. At 5, instead of the really measured vehicle speed over ground, a pseudo-running axle speed is now present, which is compared at the subtraction point 6 with the measured axle speed from the tachometer machine 3. The speed difference determined in the subtraction point 6 is evaluated in a multiplier 7 with a suitable constant or speed and / or traction-dependent factor entered at θ.

The value obtained is subtracted in a subtraction point 9 from the set value of the engine slip frequency f _g ,,. In a summer IO is the sum of rotational frequency f _red and desired motor slip frequency, the inverter frequency alo stator frequency of the drive motor 2 is formed.

At 11, the value of the expected acceleration or deceleration is derived, derived from the traction or braking force and the vehicle mass. In locomotive, the trailer load must be considered, which can be done with automatic adaptation. This value is integrated in an integrator 13 to a speed value of a pseudo-running axis. The integrator 13 is dimensioned so that it integrates faster by a small tolerance range than corresponds to the vehicle acceleration, so that the-pseudo-Laufachsdrehzahl the vehicle actual speed would run slowly ahead. The integrator 13 therefore receives an additional feedback via a comparator 14, the switching points 15 and 16, and the disposable rectifier 17; 18 or other, only signals of a polarity-transmitting arrangements, as well as an addition point 12. In'Comparator 14 of the inte-

grator output, d. H. compared the pseudo-Laufachsdrehzahl with the speed of the real axis. Positive difference (xL h, the pseudo-running axis is running faster) is given via 17 to the integrator 13 only in the operating state "drive" (15 closed) and then controls down the pseudo-running axis until it coincides with the speed of the real axis. Negative difference (i.e., pseudo-run slower) is applied to integrator 13 via 18 only in the "brake" state (16 closed) and then controls the pseudo-run axis up until true axis alignment. As a result, as long as the real axle is rolling, the integrator output is no longer accelerating or decelerating than the vehicle. The speed values coincide, and at the subtraction point 6 no speed differences occur.

In the event of wheel slip, in the "driving" state, the axle will ultimately accelerate more strongly than the vehicle. The integrator 13 can not now be taken over the feedback, because at 17 a signal of this polarity is not transmitted. It arises at the subtraction point 6 a Drehzahldifforenz, as between the drive axle and a real axle. When braking, the polarity of the difference reverses, causing the feedback signal above 16; 18 is headed. The speed difference signal occurring at the subtraction point 6 then controls, as described for the reference numerals 1 to 10, the torque of the drive motor.

The pseudo-running axle speed has already reached a value which no longer corresponds to the speed over ground but to an axle already rotating with a slip on the rail, as it is used to transmit the maximum speed.

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times possible traction is necessary. During the emergence of this slippage · d. H. from the pure rolling of the driving axle, it is accelerated barely measurably faster than the vehicle. The integrator 13 can <och until then follow the axis speed. A stronger acceleration of the driving axle only starts when it has exceeded the slip of the maximum friction coefficient.

Without further action, the pseudo-Laufachsintsgrator 13 would now continue to run freely, the pseudo-running axis is gradually faster with respect to the vehicle. The drive axle would also increasingly slip and finally get into skidding.

To prevent this, the scheme is designed so that the wheelset or the wheelset group by reducing the driving force of the engine (F _Mot ) (or braking force during braking) over the adhesion maximum back across is returned to the stable slip range. Here, 19, 20 and 21 form a Umpolvorrichtung that exchanges the polarity of the speed difference signal in braking mode. At 22, a differentiating device is referred to, which forms the first time derivative of the speed difference signal. Denoted at 40 is a first-order delay element that somewhat flattens the Ac tleg of the output signal of FIG. The output of the delay element 40 is further guided via an electronically operated switch 41 with normally closed contact to a limit value A3 , which outputs a binary signal to an OR gate 44. A feedback leads to a timer 42, which opens the switch 41 after reaching a response delay and closes this again after a further delay time. This will be undesirably long signals

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excluded »in the sense of process monitoring. The JDER gate 44 goes to a switch 31 and via an inverter 45 to the reset input of a timer 46 with OFF delay, which has been set by the output of the limit stage 43. The timer 46 triggers another timer 47, which has a switch-on delay. The upper timer 47 is a further Schalttsr 48 actuate, the output of a Maximalwertausw <stage 5.1 sets to a Schmitt trigger 52 and this au triggers, which can go through a control switch 53, a further signal to OR gate 44. The maximum value selection stage 51 receives from the Differenzinrvorrichtung 22 and a downstream inverter 49 on the one hand, a direct input signal and on the other hand via a third differentiator 50 additionally differentiated input signal. The maximum value selection stage 51 only lets through the signal with the larger value of both. The control switch 53, via which the signal from Schmitt trigger 52 can reach the OR gate 44, is actuated by a triggering stage, which consists of the elements 54, 55, 56, 57, 58, wherein the measured axle speed f and z , B. the measured motor torque Md. Use find.

The axle speed f is differentiated in a 2- differentiating member 54 and as Achsbeschleur., A _{R a} . via switch (directly when driving or inverted when braking) a summation point 55 is supplied to which also the measured motor torque Md. The output of point 55 is the calculated tension F _z , which transmits the wheel to the rail at the same time. A spin results in a force distribution in which only a part of the tensile force is still transmitted to the rail and the over-

slippery part accelerates the rotating wheel mass. Conversely, when the wheelset decelerates, the kinetic energy becomes free again for traction transfer and adds to the engine torque. 0.h. It is necessary to consider the kinetic energy of the wheel set if mon wants to determine the real tensile force transmitted to the rail. This is done by the summation point 55 to the measured engine traction F _M «. or the motor torque Md. ". the (also ge Mot is ^{v ö}

measured) Radsatzbeschleunigung ι rated with the wheelset mass accordingly, added (when driving negative, positive when braking, as shown in 54, 59, 55).

The thus determined tensile force value F- is differentiated in a first differentiating element 56 and fed via a negation element 57 to a threshold value switch 58 which controls the conscious control switch 53. Only with negative output of the first differentiating element 56, ie with decreasing transmitted Zugkrafc, the threshold value switches 58, whereby the OR gate 44 receives no further input signal via the b input and - if at the a-input at this time also no Input signal is present - no more output signal. As a result, the 1st timer 46 is reset via the reset A cc. It is only switched on again when an acceleration or deceleration triggers the limit value stage 43 and actuates the switch 31 for influencing the pseudo Laufachsintegrators 13 via the OR gate 44, ie, a new spin start begins.

The arrangement works as follows:

If at the difference former 6 a speed difference appears, the wheels, as described above, have exceeded the slip on the rails, which is the largest power transmission

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allows. They enter the unstable area of slip «d. H. with even greater slippage, the adhesion value becomes smaller again. The now increasing torque surplus accelerates compared to the vehicle mass only small rotating mass of the wheelset with drive motor relatively quickly. The increase in the speed difference is detected in the differentiator 22 and brings about the delay element 40 (to filter out short-term disturbances), and the switch 41, the limit stage 43 to respond. Their output signal is actuated via the OR gate 44, the switch 31, whereby one of the expected Beschleunigungswsrt 11 and a constant added thereto (at 33) formed and inverted in the inverter 34 signal via the time stage 32 and the addition element 12 at the input of the integrator 13 is effective becomes. The time stage 32 lets a part of the signal pass immediately, the remainder with a delay of the first order to the full height. A drop delay for the signal does not include the time step 32, as indicated symbolically. As a result, the integrator 13 slows down and begins to integrate in the reverse direction as soon as the additional signal exceeds the direct signal. The pseudo-Laufachsdrehzahl is thus smaller. As a result, although the speed difference at the subtraction point 6 initially increases even faster, at the same time the torque of the drive motor is also reduced to a greater extent with the larger speed difference signal. The further acceleration of the wheels hurt thereby, the wheelset begins to "catch" again, d. H. to run back into the stable slip area. Since in this case the wheelset speed again approaches the pseudo-Laufachsdrehzahl, and the speed difference signal at the subtraction point 6 is again smaller. The downward control of the integrator 13 via the switch 31, however, has to be continued for so long.

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are maintained until the wheel set has again reached the stable slip range, ie has run back above the maximum adhesion value of the adhesion value / slip curve. Otherwise, the system would remain in the unstable region and eventually skid.

This is the purpose of the Schmitt trigger 52 through the inverter 49 for negative - is sensitive, thus reducing the speed differential signal and its signal is also outputs it to the OR gate 44th He is after response of the threshold level 43 after expiration of the second timer 47 and another switch 48 effective. By means of the maximum value selection stage 51, the third differentiator 50 receives the Schmitt trigger 52 with an additional leading signal ", which means that it can already respond before the limit value stage 43 has fallen back again. As a result, a gap in the output signal of the OR gate 44 at the zero crossing of the

 Signal avoided. This could also - alternatively be achieved by an additional delay in the delay stage of the limit stage 43 in the absence of the elements 50 and 51. Due to the delay time of the second timer 47, the Schmitt trigger 52 can not respond until the limit value stage 43 had switched on by this minimum time; as a result, short-term disturbances "that do not represent any real spin-offs" remain without any further effect. The fallback time of the first timer 46 ensures that the Schmitt trigger 52

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can remain effective for a reasonable period of the negative - - signal «if the threshold level 43 has already turned off again.

Thus, the Schmitt trigger 52 receives dv ο additional signal for the pseudo-Laufachs integrator 13 so long until the

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(negative) - Signal goes through zero again.

f-] it of the additional arrangement according to the invention from the elements 54 to 58 (or 59), which always outputs a signal from the threshold value switch 58, when the tensile force transmitted to the rails shows a falling tendency, a more accurate determination of the time is possible In dam the wheel set over the frictional maximum begins again to enter the stable slip area. Exactly at this time the signal appears at the threshold value switch 58 and switches off by means of the control switch 53 a Schmitt trigger 52 still pending signal, whereby the additional signal of the integrator 13 of the pseudo-running axis is interrupted and can accelerate it again.

The operations are to be further illustrated with reference to FIG. 2. FIG. 2 shows an adhesion curve H for a transmittable tensile force F between wheel and rail as a function of slip ^ n or Δν. The mode of operation is shown here for the case in which the tensile force setpoint is relatively close to the adhesion limit. The reference numerals 101 * to 106 'are the corresponding points on the setpoint line through which the motor characteristics 101 "to 106" are respectively laid by the motor control Arrows from the motor characteristics (eg 101 ") to the associated operating points (eg uLQj)) show how much the An signal has shifted the respective motor characteristic over the elements 7, 9 and 10 of Figure 1. The arrow length is therefore proportional to the Δη signal.

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The process is considered from the operating point '0.OJj starting, since the target tensile force as a wheel circumferential force on the rail is slightly higher than the traction at maximum 2km / h slip after the adhesion curve, the wheelset starts after the maximum in to run the unstable slip area. Due to the greater acceleration iet already a small Δη emerged; see. the engine characteristic curve 101 "is shifted slightly to the right and the pulling force is reduced from 101 'to U.sub.L.) The remaining traction override from / ίθί to the adhesion curve H further accelerates the wheel set, with only the residual tensile force acting as traction force up to the traction curve. The wheel set accelerates along the curve piece 107, the Δη value increasing and the tensile force decreasing, as shown by the changed values, for example, at .02 2. The rising Δη signal brings the limit value stage 43 in FIG triggers the reversal of the pseudo-Laufachs integrator 13.

The pseudo-Laufachsdrehzahl is decreasing, thereby the Δη signal is initially even greater and reduces the traction over the control so far that it falls below the adhesion curve H. The excess traction is negative, d. H. The wheelset begins to decelerate and return to the maximum force. The thereby passed points ttOj) and U.03 show that the Δη signal is again smaller. The wheelset again approaches the speed of the pseudo-axis on the axis; However, it slows faster than this at now increasing traction. After passing through the point ^ .OJy in the direction uOa, η does not become smaller. At this time, the intervention in the pseudo-barrel axis must be stopped as quickly as possible, d. H. the engagement via the elements 33, 34, 31, 32, 12 goes over zero and is closed

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lends again positive · This zero crossing is detected by the elements 50 »51, 52. The Schmitt trigger 52 switches back and the pseudo-run axis accelerates again. The wheelset reverts to the point (10y) with increasing tractive force, and the process begins again, so that the wheelset constantly swings around the traction limit as long as it exceeds the specified torque setpoint This requires precise metering of engagement with the pseudo-Laufachs integrator 13. If the intervention is too strong, the pseudo-Laufachs speed is returned too fast, then the zero crossing of

^{8r3t a little} later, and the operating point in Fig. 2 runs over 6.0a further to the left on the curve H. The traction is reduced too much before the pseudo-run axle can accelerate again. If the intervention is too weak, that is, if the pseudo-running axis is returned slowly, the zero crossing can occur even before passing through the maximum of the adhesion curve H, to the right of the point 6.09 in FIG. 2. Then the system remains in the unstable slip area, and the scheme fails by "creeping" passing through the wheel set. This vote has been critical, especially since the adhesion curve is dependent on the surface finish of the rail.

By the invention, the tuning & echwierigkeiten be mitigated «by now the engagement in the pseudo-barrel axis can be generously sized. The correct time of its termination, which would then be determined too late by the previous method, is now by the superimposed function, in which the actual traction and its tendency is calculated depending on the wheelset speed and the engine torque, more accurate than before, with the best possible setting certainly. By driving the control switch 53, the intervention signal is then turned off.

Claims (6)

X. Method for controlling the drive and / or braking force of the traction motors of a Laufachslosen traction unit at the frictional limit of the wheels «in each of the driven wheelset or each driven wheelset in repeating game sequences each by increasing the drive or braking force the transition to the unstable slip range is determined on the basis of the onset of greater acceleration (deceleration), the wheelset or the wheelset group is then returned to the stable slip area by reducing the drive or braking force again beyond the traction maximum and subsequently the drive or braking force Completion of the reduction undergoes an increase, etc., characterized in that «the respective time of termination of the reduction of the driving or braking force of the motor (FM" t) from c'er falling tendency of x not 'real on the rails transferred train or B Remark (Fy or Fß) is detected, in which the real effective on the rails force (Fz or F_) at the Redaufstandspunkt from the drive or braking force of the engine (> cMot) and the wheelset mass (mRa (jgatz) multiplied by the measured Radsatzbeschleunigung (aDacj8atz) calculated, formed from this value in a Difforenzierglied the 1st time derivative and this is supplied as a tendency signal mit.der the falling tendency corresponding polarity (+ or -) a switching means, the reduction of Drive or braking force of the motor "· i ^ Mot) bsi overrun of a limit value. 1. is applied to a first input (a) of an OR gate (44), 2. via an on-delayed timer (42) one in front of the input to the limit stage (43) lying switch (41) drives with normally closed contact and 2. Arrangement for controlling the drive and / or braking force 22b OSS - 16 - the traction motors of a Laufachslosen traction vehicle at the frictional limit of the wheels, the traction unit is equipped with an integrator as pseudo rotor, in each of the difference of the external size of the integrator and the rotational speed of an associated drive axle serves as a measure of wheel slip and to reduce the drive or braking torque at which is detectable by means of a differentiating device on the first time derivative of the speed difference of the transition to the unstable slip range based on the onset of stronger acceleration and in which a limit level is provided, the signal to the integrator an additional, the supplied target value for acceleration or deceleration counteracting input to Return in the stable slip region aufschaltet, characterized in that the output of a first differentiating member (56), for the first time derivative of the determined drive or braking force t, a threshold value switch (58), which switches off the signal for the additional counteracting input variable to the integrator (13), is applied in the polarity a; i corresponding to a falling tendency. Arrangement according to Claim 2, characterized in that the axle acceleration is determined from an axle speed f _pot via a second differentiating circuit (54) and fed to this value as a negative quantity - for driving directly and for brakes via an inverter (59) - a summation point (55) is, where the measured engine torque ^Md is applied and ^a ^ ^s P ^ositive size whose output, at which a calculated tension or braking force (F _2, F ') is removable, via the first differentiator (56) and a NOT gate ( 57) to the threshold value switch (58). - 17 - is closed is "connected to a control switch (53), via which the signal for the additionally counteracting • input variable to the integrator (13) can be switched off. 3. on the set input of a first timer (46) is connected, via a second timer (47) actuates a further switch (48), the first or a third differentiating member (50) obtained second time derivative of the differential speed over a Maximalwertsoswahlstufe (51) switches to a Schmitt trigger (52), which is connected via the control switch (53) to a second input (b) of the OR gate (44). 4. Arrangement according to claims 2 and 3, characterized in that the limit value stage (43) removable signal 5. Arrangement according to claim 4, characterized in that the third differentiating member (50) to the output of the differentiating device (22) for the ersto time derivative of the differential speed via an inverter (49) is connected. 6. Arrangement according to claim 4,. characterized in that the first timer (46) operates off-delay and that its output is connected to a switch-on delayed timer (47) and the reset input is connected via an inverter (45) to the output of the OR gate (44). _Hienu t pages drawings