DE3103967A1 - ANTI-BLOCKING SYSTEM FOR WHEEL BRAKE VEHICLES - Google Patents

Description

Möller. STONMiHislfR ··· * * ·· * ···· * ·· * «Nippon Air Brake F8

"" 6 - *

DESCRIPTION

The invention relates generally to so-called anti-lock braking systems and in particular to a slip control or anti-lock braking system for wheel-braked vehicles, as in the preamble of claim 1 specified.

An anti-lock braking system prevents the locking of a vehicle that has at least one wheel with a brake Wheel and thus improves the braking behavior of the vehicle on every road. Common slip control systems included Devices for measuring deceleration, slip and acceleration conditions of the wheel. Exceeding a given deceleration or slip threshold has a Reduction of the brake pressure and the wheel exceeding a given acceleration threshold either a maintenance of the preferably reduced brake pressure or a gradual increase of the same for Episode.

The speed of the wheel is determined by an associated wheel speed sensor measured and based on the output of this sensor an acceleration, deceleration or a Wheel slip detected. One on the side of the wheel The rotating sensor part attached is a stationary one attached to the chassis or to the body of the vehicle Sensor part opposite. When decelerating or accelerating, there are relative movements due to the inertia of the vehicle body between the frame or the body and the wheel, so that the stationary sensor part is relative to the rotating sensor part. When the brake pressure for the wheel is increased to reduce the speed of the wheel, causes

TER Meer-Müller - STEiNMtiiSTOR ·· - * * ·· "- ^: · - * ·· * -. Nippon Air Brake F8

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the relative rotation between the stationary and the rotating sensor part an apparent reduction in the real wheel speed, and if the wheel brake pressure is used Increasing the wheel speed is reduced, the opposite effect occurs. The true or actual wheel speed changes in the wheel brake pressure follows almost instantaneously, whereas a relative rotation of the stationary one follows Sensor part of a change in wheel brake pressure with some delay.

Consequently, the wheel speed change detected by the wheel speed sensor becomes be greater than the actual wheel speed change, and the wheel speed determined by the wheel speed sensor the actual wheel speed runs in phase neich. With slow ones Wheel accelerations or decelerations is the increase in the wheel speed change and the speed phase lag angle small, but relatively large for large acceleration or deceleration values.

In the case of a two-wheeled vehicle such as a motorcycle, the above-mentioned relative rotation between the two sensor parts is relatively large.

The stationary rare speed sensor assigned to the front wheel * - part sits on the front fork, which moves relatively strongly with respect to the front wheel when the brake pressure changes which carries the rotating wheel speed sensor part. Therefore, if there are large changes in the wheel deceleration or wheel load

-j. acceleration the speed determined by the wheel speed sensor deviate greatly from the real or actual wheel speed and lag far behind the actual speed in phase. This measured value distortion and phase shift have a disruptive effect on the brake pressure control. Especially when with a certain Wheel acceleration or deceleration system the brake pressure reduction is interrupted, the Hri'iusclruok sinks extremely

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TER Meer-Müller · STElNMElsfEi ^ ... "" .. '.: ..' .Nippon Air Brake F8

or more than required, and accordingly the braking distance of the vehicle becomes longer.

The invention is based on the object of a slip control system of the type mentioned at the beginning so that the explained deficiencies inherent in the state of the art to be overcome.

The inventive solution to the problem posed is brief specified in claim 1.

Advantageous further developments of the inventive concept are contained in the subclaims.

The slip control system according to the invention has a special feature Feature a second brake pressure control stage and thus enables an optimal design of braking processes highest slip resistance and shortest possible braking distance.

An exemplary embodiment having the features of the invention is described in greater detail below with reference to a drawing explained. Show it:

Fig. 1 is a block diagram of the one described below Embodiment of the invention,

FIG. 2 is a schematic representation of a system connected to the slip control system of FIG. 1 Wheel brake system, and

FIG. 3 graphical characteristic curves and signal representations for the exemplary embodiment from FIG. 1.

TER MEER · MÜLLER · STEINMEISTt ¹ R ·· "* '» ·' * '>·''■ · · "« Nippon Air Brake F8

A wheel speed sensor 1, connected to a wheel of the vehicle, of the slip control system according to the invention shown in FIG. 1 emits a pulse signal, the frequency of which is proportional to the wheel speed. This pulse signal is converted by a wheel speed sensor circuit 2 into a speed signal V, the analog odot Diij i L.ilwert of which is proportional to the wheel speed. L) La Schul turn) 2 supplies the speed signal V to a generator 3 to determine an approximate vehicle speed (frame

1-0 speed), a sliding signal generator 4 and a Differentiating circuit 5. The actual vehicle speed, which is normally not measurable, is simulated by generator 3 and in the form of a vehicle speed record E (Fig.3A) to determine wheel slip the sliding signal generator 4, which in turn compares the signal E with the speed signal V and according to the formula below a slip F is determined:

2 - -j _ wheel speed.

Vehicle speed

If S is greater than a predetermined slip threshold of E.g. if 0.20 is the generator 4 gives a high slip signal S = "1" from, otherwise a low-lying signal "0".

The differentiating circuit 5 differentiates the speed signal V from the transmitter circuit 2 and thereby generates a signal V and proportional to the wheel acceleration or deceleration are provided to a deceleration signal generator 0 and an acceleration signal generator 7 from. The delay signal generator 6 compares the output signal V with a given one Delay threshold of e.g. -1.5 g, and if the absolute value of the signal V is greater than the Ver / .öijci-utic |:; i; ehwe L L -wert the generator 6 outputs a delay signal, -b in

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Form of an output "1", otherwise the output signal of this delay signal generator 6 = "0".

The acceleration signal generator 7 compares the output signal V of the differentiating circuit 5 with a given acceleration threshold value of e.g. 0.5g, and if so V is greater than this threshold value, the acceleration signal generator generates 7 a high acceleration signal t-b - "1", otherwise a low signal "0".

The output terminal of the delay signal generator 6 is connected to the set terminal S of a flip-flop 8, an input of a OR gate 9, a switch-off delay timer 21 and an input of another OR gate 26 connected. Of the The second input of the OR gate 26 is connected to an output of the sliding signal generator 4.

When the delay signal -b eus is received by the generator 6, the output of the timer 21 goes high to "1" and maintains this high value for a given period of, for example, 0.1s after the delay signal -b has ^{disappeared (transition to 11 O ")} and then goes down to "0." The reverse output Q of flip-flop 8 is connected to the second input of the OR gate 9, and the reset terminal R of flip-flop 8 is at the output of the delay signal generator 7. The output of OR- Member 9 is connected to the reset connection R of a first up counter 10, the clock connection C of which is connected to the output of an AND element 11, which in turn has an input connected to a pulse generator 12 emitting clock pulses with a given frequency fo. The output 0 of the counter 10 is connected to the input I _{2 of} a comparator 13, the other input I _{1 of which} with a predetermined üigiLaiwert N

.) 0 is set. The output 0 of the comparator 1.3 is with one

Meer ■ möller · stpinmeisttr '"'" .. *.: .. ".. Jiippon Air Brake F8

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Neg. Input of AND element 11 connected. The output O of the first up counter 10 is also connected to the input D of a locking circuit 14, the locking connection L of which is connected to the output of the delay signal generator 7. The latch circuit 14 stores a count value of the counter 10 at the moment when the output of the generator 7 goes high to "1". A complementary value of the count value of the counter 10 is available at the reverse output Q der.Verriegelung 14 and goes to the input I _{1 of} a second comparator 15, the other input I _{2 of which is} at the output O of a second up counter 16.

A clock connection C of the counter 16 is connected to the output of an AND element 17, which in turn has an input connected to the pulse generator 12. A reset connection R of the counter 16 is connected to the output of an inverter 29, which in turn has an input connected to the acceleration signal generator 7. The output O of the second comparator is connected to a set terminal S of a flip-flop 18 and a negative input of the AND element 17. As soon as the Aunganq of the lock 14 is equal to the number word of the two-tone counter 16, gohfc the output of comparator 1 ^r ><iuf"1" high to set flip-flop 18 and block the AND gate 17 yu.

The output of OR gate 26 is connected via an AND gate 20 to the reset terminal R of flip-flop 18, and a Neg. Input of AND element 20 is at the output of generator 7. The Q output of flip-flop 18 is at an input of one AND gate 19, the second input of which with the output of the signal generator 7 and also with a negative input of a AND gate 22 is connected, the other input of which is in turn connected to the output of the timer 21 isL.

IKR MEER · MüLLEIR · STCINMEIsf Kf * ... "'.. *.: .. * .. * .fci.ippon Air Brake F8

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The output of AND element 19 is connected to a first input of an OR element 23, the second input of which is connected to the output of AND gate 22 is connected. The output of AND gate 20 is connected to a third input of OR gate 23, and the output of which is in turn connected via an amplifier 2 4 to the solenoid 25 of an inlet valve 32 shown in FIG tied together.

The output of the AND element 20 is via an amplifier 27 with a magnetic coil 28 of an exhaust valve shown in FIG 33 connected. With the output of OR element 23 or AND element 20 rising to "1", amplifier 24 activates the inlet valve winding 25 by a current I, and with the output of AND gate 2 0 going high, the amplifier is activated 27 the exhaust valve coil 28 by a current I.

The flip-flop 8, OR gate 9, the first up counter 10 and the latch circuit 14 form a circuit for determining a decrease in wheel deceleration or a tendency to increase the wheel acceleration in a time interval from the point in time after the maximum deceleration has been exceeded the delay is a given delay threshold has reached up to a second point in time where the wheel deceleration is adjusted to the given deceleration threshold value is enough. The flip-flop 8 is activated by the delay signal -b of generator 6 is set, its Q output becomes

₂ r, "0". When the delay signal -b disappears, the output of the OR gate 9 goes down to "O" and resets the first up counter 10, which then starts counting the clock pulses of the generator 12 and transfers its count value to the latch circuit 14. At the moment when the acceleration signal generator 7 outputs the acceleration signal + b, the latch circuit stops

TER MEER-MÜLLER · STEINMEISTCR ·· * · "" * ·· "· ^: * - '· - -' Nippon Air Brake F8

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14 fixes the count value of the counter 10. This saved The count is proportional to the time interval from the point in time after the maximum delay has been exceeded the delay has reached a given delay threshold by a second point in time where the wheel deceleration at the Verzöqorunqssehwpllworl. onyclichen is enough. If the stored numeric word is kloin, this means a large decrease in the rudder lag or tendency of the wheel acceleration to decrease. On the other hand, when the stored count value is large, the deceleration tendency is decreasing or the tendency to increase acceleration is small.

The comparator 13 compares the count value of the first counter 10 with the predetermined value N and closes if both values become equal, the AND gate 11 by its high output signal "1", so that the clock pulses of the generator 12 can no longer get to the counter 10, folqlic-h can Counter not above the default value N hinuu.s v.'ih U; n.

The second up counter 16, the second comparator 15, the flip-flop 18 and the AND gate 19 form a circuit for Specifying a definable time interval in which immediately after the wheel acceleration has reached the given acceleration threshold value, the wheel brake pressure is increased rapidly. As soon as the acceleration signal + b is generated by the generator 7 or the output dt * f. Inverters 29 goes down to "0", the counter 16 starts the clock pulses fo of the pulse generator 12 to be counted and in the comparator transferred to. The output 0 of the preset M, which forms the complementary value of the stored digital value, is with the numerical dos counters 16 before, and as soon as boide values are the same, the flip-flop 18 is raised to "1"

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MEER · MÜLLER ■ STEINMEIST4fR ··· "*. · *.!. · * ..". *. Nippon Air Brake F8

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The output of the comparator 16 is set so that its output also becomes "1". Since the acceleration signal + b still goes to the other input of the AND gate 19, its Output when flip-flop 18 is set "1". At the same time, the comparator 16 prevents this by blocking the AND element the forwarding of the clock pulses of the pulse generator 12, the Counter 16 cannot continue counting.

Polarity is the given time interval for the rapid one Increase in wheel brake pressure equal to the period from the beginning the counting of the clock pulses fo of the generator 12 when the acceleration signal + b occurs until the Equality between the count of counter 16 and the reverse output Q of latch 14 elapses. If the one in the Latch circuit 14 stored count value of the first counter 10 is large, then the predetermined time interval briefly for the rapid increase in wheel brake pressure, and vice versa.

The wheel brake system shown in FIG. 2 includes a Control cylinder 30, which is connected via a line 31 to the inlet valve 32 and the outlet valve 33 and via a line 34 is connected to a disc brake 35 attached to the wheel. The inlet valve 32 shown schematically in FIG. 2 and exhaust valve 33 are of a known type and are sometimes referred to as a shut-off valve and a drain valve.

The discharge port of the exhaust valve 33 is via a line 39 connected to a reservoir 37 which is connected via a line 40 to the inlet of a pump 38, the outlet of which is connected to the line 31 via a line 41.

TER MEER · MÖLLER ■ STEINMEISTEÜR · * · "* ·· * - * ·· * ·· .Siippon Air Rrake F8

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In the idle state of the solenoids 25 and 28 for the inlet and outlet valves 32 and 33, the control cylinder 30 is connected to the brake cylinder 36 of the SchGibonbroin.se 35, and the wheel brake pressure is increased. If, on the other hand, both magnetic. Coils 25 and 28 of the valves 32, 33 are energized, then the connection between the control cylinder 30 and the brake cylinder 36 is cut off and the outlet opening of the outlet valve 33 connects the brake cylinder 36 with the reservoir 37, consequently the brake pressure drops and the pump 38 leads Brake fluid through lines 40 and 41 back into line 31. If only the solenoid 2 '.> Of the inlet valve 32 is excited, then the connection between the control cylinder 30 and the brake cylinder 36 is blocked and only the outlet valve 33 remains connected to the brake cylinder 36, consequently the brake pressure on the wheel remains constant.

The operation of the system in connection with FIGS. 1 to 3 will now be explained. If the driver of the vehicle has the If the control cylinder 30 is actuated at a point in time to, both magnetic coils 25 and 28 of the inlet and outlet valves 32, 33 are activated still in the idle state and connect the Stouer cylinder JO with the brake cylinder 36, consequently the brake pressure P on the wheel (see Fig. 311) increases by actuating dos Sl.ouorzylinders 30 reduce the wheel speed. Consequently, the speed signal V from the encoder circuit 2 and the an output V of the differentiating circuit 5 representing an acceleration or deceleration is smaller, see FIGS 3B. The simulated vehicle speed signal shown in Figure 3A E is slowly getting smaller.

At a time t. the wheel deceleration reaches the given Delay threshold value or the output V of the circuit 5 the threshold value -go in Fig. 3B. The shown in Fig. 3C

TER meer · Müller · STEiNMEiSTER "- '' .. *«. ·· * .. * .Mppon Air Brake F8

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set delay signal -b of generator 6 arrives via the timer 21 to the AND gate 22, but the acceleration signal generator connected to the negative input of the AND gate 22 7 does not yet generate an acceleration signal + b, consequently the output of AND gate 22 as well as of OR gate 23 = "1". The amplifier 24 now activates the solenoid 25 of the inlet valve through the current I 32. Since the delay signal -b goes to OR gate 26 at the same time, its output and the output of AND gate have 20 has the value "1", so that the amplifier 27 now excites the solenoid 28 of the outlet valve 33 by the current I. Both valves 32 and 33 are now activated and block the connection between the control cylinder and the brake cylinder 36, brake fluid is drained from the brake cylinder 36 into the reservoir 37 and the brake pressure P am Brake cylinder 36 decreases over time, see Fig. 3H.

On the other hand, the flip-flop 8 is set by supplying the delay signal -b to its set terminal S, its output Q becomes ¹¹ O ". As the brake pressure P falls, the wheel deceleration decreases, and at a point in time P ₂ it becomes smaller than the threshold value -go The delay signal -b disappears, and consequently the outputs of the OR element 26 and of the AND element 20 return to "0", the solenoid 28 is de-energized and the outlet valve 33 returns to its rest position but the output of the switch-off delay timer 21 still remains at the high signalpcqel, the inlet valve 32 also remains activated and the brake pressure P consequently remains constant, see FIG. 3H.

TER Meer ■ Müller · STEiNMEisif.R ··· * "..".: .. '- "-Mippon Air Brake F8

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As soon as the delay signal -b disappears, the first counter 10 is activated by the output which goes back to "0" reset by OR gate 9, the counter starts again to count the clock pulses fo of the pulse generator 12.

In the meantime, a bush euhi qun <j occurs at the had on, and at a point in time t-, the wheel acceleration exceeds the predetermined threshold value or the output V of the differentiating circuit 5 exceeds its threshold value + go in Figure 3B. The acceleration signal + b generated by the generator 7 goes to the negative input of the AND gate 22, the output of which is consequently "0". Since the flip-flop 18 has not yet been set and the delay signal -b has already disappeared is, the signals at the first and third input of the OR gate 23 have the low level, and consequently the output of OR gate 23 goes back to "0" with the low output of AND gate 22. The current flow Is the inlet valve solenoid 25 stops, see Fig. 3F, the inlet valve 32 returns to its rest position. There now Both valves 32 and 33 are in the rest position as shown in FIG. 2, the control cylinder 30 is directly connected to the Brake cylinder 36 is connected and supplies it with its brake pressure P, which rises rapidly according to FIG. 3H.

On the other hand, the acceleration signal + b goes to the lock terminal L of the latch circuit 14 and to the input of the inverter 29, the output of which to the reset terminal R of the second counter 16 is connected. Uie interlock circuit 14 stores the count of the first counter 10 at the moment when the acceleration signal + b reaches the latch terminal L of the circuit 14, and at the same time the second counter 1G starts the clock: pulses fo of the pulse generator 12 to be counted.

* · - * Nippon Air Brake F8

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As soon as at a time t, the count of the second Counter 16 equal to the complementary output Q of the stored Count value in the interlocking circuit 14, the comparator 15 sets by its "1" going out * - output signal the flip-flop 18, consequently its output goes also to "1" and into one input of AND gate 19, since the AND gate 19 still receives the Beüchlounigungssignal at its other input + b receives, the output of 19 goes to "1" when flip-flop 18 is set, and the current I becomes

begins to flow through the inlet valve spool 25, the brake pressure P on the wheel remains constant.

As described, in this exemplary embodiment the brake pressure P remains at the wheel from time t. constant where the comparator 15 the flip-flop 18 sets. However, it is also possible after the point in time t. the brake pressure gradually increases raise; in this case, between the output Q of flip-flop 18 and the one input of AND gate 19 is a Arranged by the output of flip-flop 18 driven pulse generator, the square-wave pulses with a given frequency generated and thus the inlet valve solenoid 25 intermittently energized, so that the brake pressure P gradually with the Time increases.

The wheel threat signal V approaches the estimated vehicle speed signal E. At time t_, the wheel acceleration value V is smaller than the threshold value go, the Delay signal + b disappears according to FIG. 3D, and the output signal from AND element 19 and from the OR element thus go 23 back to "0". The delay time of the timer 21, which has the high level in this time, runs forward the disappearance of the acceleration signal + b, consequently the inlet valve solenoid 25 at time t "with the

* 0

TER MEER · MÜLLER · STEINMFJSTfiR ... "* .. *.! ..>'-Nippon Ai Γ Brake I · ¹ 8

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Disappearance of the acceleration signal + b de-energized. The brake pressure P increases over time, see FIG. 3H.

With increasing brake pressure P, the wheel is decelerated more strongly: at time t, the threshold value -go is reached, and the generator 6 generates the deceleration signal -b. As a result, the output of AND gate 20 and thus of OR gate 23 go high to "1", and the solenoids 25 and 28 of the inlet and outlet valves 32, 33 are excited by current I and I ₃ , s. Figures 3F and 3G. After time t, the brake pressure P at the brake cylinder 36 decreases again over time, see Fig. 3H. The wheel deceleration decreases as the brake pressure P falls after the maximum value has been exceeded, see FIG. 3B. At time t ₇ it becomes smaller than the threshold value -go, the delay signal -b disappears, and the first counter 10 begins, as described above, with the '/, uhlunq tier lmpuU-.e fo of the generator 12. In this case, however The relationship between the wheel speed signal V and the vehicle speed signal E is less than a predetermined ratio “C” before the deceleration signal -b disappears. This specified ratio ■ £ · corresponds to (i - specified slip threshold value) and is, for example, 0.80. Since at time t _{7 the} wheel slip value becomes greater than the specified slip threshold value, according to FIG. As a result, the outputs of 20 and 23 remain at "1", although the delay signal -b disappears at time t-. According to Fig. 3H the Brem.'Klriick P sinks after t .. wi-if ei- <il>.

As the brake pressure P is reduced, the deceleration increases After the maximum value has been exceeded, and the acceleration value V reaches the threshold value at time t " + go, consequently the generator 7 gives the acceleration

TER MEER · MÜLLER ■ STEINMEISTi-üR * - * ».'-.'- ♦ - --Nippon Air Brake F8

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because the second counter 16 starts counting the clock

pulse fo, and with the time t_ or t. reaches the

Count of 16 first the complement äruur.qanq the latch circuit 14.

When the brake pressure P is maintained, the wheel speed signal V approaches the approximate vehicle speed E. At the time t _in , the acceleration signal + b ends and goes to 20 ". The inlet valve 32 returns to its idle state and allows the brake pressure P to rise.

The functions described above are repeated continuously, and the brake pressure P for the wheel becomes optimal regulated.

In the embodiment described above, the time interval between the point in time when the wheel deceleration after exceeding the maximum value the deceleration threshold value -go reaches up to the point in time where the wheel acceleration the acceleration threshold value + go is reached, measured and as a period for a rapid increase in the brake pressure P used. However, it can also be the period between

Time at which the output V of the differentiating circuit 5 a Minimum or one that deviates from the delay threshold value -go The value reaches up to the point in time when the output V of the circuit 5 reaches the acceleration threshold value + go, can be measured and used as the period for the rapid increase in brake pressure P. Alternatively, the output of the Differentiating circuit 5 during the period of decreasing Wheel deceleration can be used as this period of time for the rapid increase in brake pressure.

TER MEER · Müller · STEINMElSf-ER ··· "'..'- I ** * .. *.; Nippon Air Brake F8

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signal + b from, so that the outputs of AND gate 20, AND gate 22 and OR gate 23 go back to "0". By blocking the line and exhaust valve «32 and 33 takes place now a rapid increase in the brake pressure P on the brake cylinder 36. At this moment, the 10 reached by the first counter Count value is stored in the latch circuit 14, and the second counter 16 starts counting the clock pulses fo from the pulse generator 12.

The output signal of the second comparator goes at time t ~ 15 to "1" when the count value of 16 has the reverse output Q of the latch circuit 14 is reached. The flip-flop 18 is set, its output goes via AND gate 19 to OR gate 23, and consequently the intake valve solenoid 25 is energized. The solenoid 28 of the exhaust valve 33, on the other hand, was at one point in time to de-excited where the acceleration signal + b from the generator 7 was submitted. As a result, the brake pressure P remains constant from time t "on.

The period between t_, where the deceleration value V of the wheel reaches the threshold value -go for the second time after exceeding the maximum, to the time t _ft , where V el ο η Bosch U ^% unii | uiu] sychwol lwort for the second time. + qo reached:, so the second speed reduction period runs faster or shorter than the first wheel speed deceleration period between the

Points in time t 1 and t ... At t ~, the wheel deceleration V reaches the deceleration threshold value -go for the first time after exceeding the maximum, and at time t ~, the wheel acceleration V reaches the acceleration threshold value + go for the first time. Consequently, the second time period for a rapid increase in brake _{pressure P between times t 1} and _{t g is} longer than the first time period for a rapid increase in brake pressure P between times t 3 and t 1. At tg or t ₃ each begins

TER meer · Müller · STEINMEIST- & R ·· Nippon Air Brake F8

As can be seen from the present description, according to the invention there is an excessive lowering of the brake pressure P due to the cant and lag due to relative rotation between the stationary and rotating Part of the wheel speed sensor 1 during the braking process through a rapid increase in brake pressure during a period of time, in which the acceleration signal + b is generated, compensated. In this way an optimal blocking protection is achieved achieved.

Furthermore, according to the invention, an excessive decrease in the Brake pressure through a hysteresis effect of the brake cylinder (Friction between cylinder and piston) by the previously explained compensates for a rapid increase in brake pressure.

Claims (11)

PATENT LAWYERS TER MEER-MÜLLER-STEINMEISTER Professional Representatives before the European Patent Office Mandataires agrees pres! 'Office europeen des brevets Dipl.-Chem. Dr. N. tar Meer Dipl -Ing. H. Steinmeister Dipl.-Ing, FE Müller _o . . .. _, Trittstrasse 4, S.ekerwall 7, D-8OOO MUNICH 22 D-4BOO BIELEFELD 1 Case: F8 February 5, 1981 Mü / Gdt / Tß Nippon Air Brake Co., Ltd. 1-46, Wakinohama-Kaigandori, Fukiai-ku, Kobc-shi, Japan Anti-lock braking system for wheel-braked vehicles PATENT CLAIMS . J Anti-lock or carriage control L sys Lein for wheel spreaders Vehicles with - a wheel speed sensor, which emits an output signal corresponding to the speed of a wheel, - A differentiating circuit for generating one of the Output signal corresponding to wheel deceleration or wheel acceleration by differentiating the wheel speed sensor output signal, - A delay signal generator, the απ the Diffcrenzicrschaltumj connected isl and a Vcf / .öqerungs- ter Meer · Müller · SteinmeisVer ··· "* ♦♦ * ····" ·· "··· Nippon Air Brake F8 signal outputs when the differentiating circuit output signal exceeds a given delay threshold, - An acceleration signal generator, which is connected to the differentiating circuit and a Gives acceleration signal when the differentiating circuit output signal exceeds a given acceleration threshold, - A brake pressure reduction stage that is dependent on from the delay signal of the delay signal generator the brake pressure supplied to the wheel brake is reduced, and - A first brake control stage, which is dependent on the acceleration signal of the acceleration signal generator either keeps the wheel brake pressure constant or increases it gradually, characterized by a second brake control stage (15, 16 ...) which, within a time interval, in which the acceleration signal generator (7) generates the acceleration signal (+ b) for a given Period of time the brake pressure (P) for the wheel brake (36,35) increases rapidly. 2. slip control system according to claim 1, characterized in that the predetermined period of time by a timer contained in the second braking control stage (12 ...) can be determined. 3. slip control system according to claim 2, characterized in that the timer is dependent on the tendency of the output signal (V) of the differentiating circuit (5) is controlled. Tt £ R MEER -MÖLLER · STEINMEIS'T W3 ... * * .. * . * ... *,. * NitUX> n Ai ir Brake F8 - 3 - 4. Slip control system according to requirement 2, characterized in that the timer is on the Basis of the deceleration and acceleration sianals (-b, + b) of the deceleration and acceleration signals (6,7) is controlled. 5. slip control system according to claim 4, "characterized in that the timer is a clock pulse generator (12) and a first counter (10) counting the clock pulses (fo) of this generator. 6. slip control system according to claim 5, characterized in that the first counter (10) the Clock pulses (fo) of the generator (12) via a beginning with the termination of the delay signal (-b) and counts with the beginning of the acceleration signal (+ b) period ending, and that the predetermined period through the count of the first counter (10) is determined. 7. slip control system according to claim 6, characterized in that the timer is further a Flip-flop (8) to recognize the Vorzfkjprmui:;! ·. i cjnnl endes and the acceleration signal start. 8. slip control system according to claim 7, characterized in that the beginning of the predetermined period of time coincides with the beginning of the acceleration signal. R MEi? R · möller · STCiNMEis'ifR ··· * .. * .... * · "Nippon Air Brake F8 9. slip control system according to claim 8, characterized in that the timer further a comparator (15) and a second counting the clock pulses of the clock pulse generator (12) Contains counter (16), which begins to count the pulses of the clock pulse generator with the onset of the acceleration signal and this counting process ended at a point in time when the comparator (15) recognizes that that reached by the second counter Count value is equal to the complementary value of the count of the first counter (10). 10. slip control system according to claim 9, characterized in that the predetermined period of time corresponds to that of the second counter (16) by influencing it corresponds to the count value reached by the comparator (15). 11. slip control system according to claim 9 or 10, characterized in that the timer further a second flip-flop (18) contains which the detection output of the comparator (15) at his Set input (S) receives and determines the end of the specified period. TER MEER · MÜLLER ■ STEINMEISTE ^ "*" "Nippon Air Brake FS 12, Rutschkontrollsystern according to claim 6, characterized in that around the Radbromsdruck (P) to gradually increase the first brake control stage is connected to a Rechteckiinpulsgenerator.