JPS6229267B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an anti-sticking system that receives and evaluates information regarding changes in the rotational speed of the wheel through a detector located on the wheel, and controls the start-up of solenoid valves, that is, inlet and outlet valves that adjust the braking pressure. load and characteristics, which has a regulating circuit (ABV regulating circuit), receives and evaluates information about the supply pressure, brake cylinder pressure, and load supplied from the brake valve via a measured value transmitter and controls the solenoid valve; a braking pressure regulating circuit (ALB regulating circuit) related to the curve, the output end of the ABV regulating circuit and the output terminal of the ALB regulating circuit are logically coupled to each other through a logic circuit to start and control the solenoid valve; The present invention relates to a safety circuit in an anti-stick and load-related adjustable vehicle braking system with a safety circuit for ABV regulation circuits (ABV-SIS) which generates a fault signal if the ABV regulation circuit does not operate regularly.

The main features of the anti-stick safety circuit for vehicle braking systems are that a monitoring circuit is provided for the prohibited condition in which the electromagnets of the inlet and outlet valves of the vehicle braking system are energized for an unacceptably long time. There is a particular thing. This monitoring circuit signals a fault condition with a time delay via a suitable fault warning device as soon as the valve electromagnet is energized for, for example, more than one second. If an ALB regulation circuit with safety circuit for ALB regulation circuits (ALB-SIS) is used together with an ABV regulation circuit, there is a risk of unstable braking driving conditions as a result of an adverse interaction between the regulation circuit and the associated safety circuit. There is. Thus, for example, a situation may arise in which the ALB regulation circuit can enter into operation during a braking process which does not lead to a reaction of the ABV regulation circuit. This means that at least the electromagnet of the inlet valve is activated during the entire braking period, for example in order to reduce the braking pressure at the rear axle to a certain magnitude or to keep it at a certain value. Since such a process usually lasts longer than the maximum energization time of the valve electromagnet by the ABV regulation circuit, there is a risk that the monitoring circuit will react and generate an erroneous signal that can cause an erroneous response of the device.

In the case of the above assumptions, if the ALB regulation circuit fails, ie after reaching the reference pressure, the inlet valve remains energized even if the pressure pe controlled by the footplate brake valve is reduced again. This creates an unacceptable situation, since the limited braking pressure set by the ALB regulation circuit cannot be reduced again.

Another error may be one characterized by the fact that no restriction of the rear axle pressure takes place when the ALB regulation circuit should be activated, thereby resulting in altered braking behavior.

In addition, the ALB-SIS may also fail, causing a false error signal to trigger the alarm system. This can also lead to an erroneous response of the adjusting device.

It is therefore an object of the present invention to prevent sticking of the type mentioned at the outset and to ensure that load-related malfunctions in the vehicle braking system are prevented if a safety circuit is provided in addition to the ALB regulating circuit. The purpose of this invention is to provide a safety circuit of the kind mentioned at the beginning, which can be avoided.

According to the present invention, in order to solve this problem,
A safety circuit for the ALB adjustment circuit (ALB-SIS) is provided, and the ALB adjustment circuit, the ABV adjustment circuit and the ALB-
If the SIS and the ABV-SIS are logically coupled to each other and to the inlet and outlet valves via a logic circuit, in the case of anti-sticking braking processes, the fault signal of the ALB-SIS is blocked and the load-related braking force adjustment ( ALB adjustment) is carried out but anti-sticking braking force adjustment (ABV adjustment) is not carried out at the same time.
SIS is blocked for erroneous signals.

The solution according to the invention provides that, during the braking process which does not lead to a response of the ABV regulation circuit but does lead to a response of the ALB regulation circuit, at least a relatively long energization time of the electromagnet of the inlet valve is not detected as an error by the electromagnet energization time monitoring circuit. This also ensures that during the anti-stick braking pressure adjustment, the error signals of the ALB-SIS cannot adversely influence the adjusted braking process.

As already indicated at the beginning, during individual ALB regulation there is a possibility that the ALB regulation circuit may fail. When this failure occurs, as soon as the inlet valve is closed after reaching the reference pressure and the pressure Pe supplied by the tread brake valve is reduced again, the valve remains in the energized state, which is unacceptable. enter the state. This means that, on the one hand, the braking pressure limited by the ALB regulating circuit is not built up again, and on the other hand, the ABV-SIS, which monitors the energization time, remains blocked thereafter. In order to avoid this malfunction, measures according to claim 2 have been taken.
This measure allows the cylinder pressure to be built up again.

ABV-SIS typically monitors the starting control time of the valve electromagnet behind the amplifier stage. ABV during ALB regulation
To allow continued monitoring of the regulatory circuit,
According to embodiments of the present invention, during ALB regulation, ABV
The starting control signals for the inlet and outlet valves generated by the regulating circuit are monitored by the ABV-SIS prior to interference by the ALB regulating circuit. In a practical circuit, this means that the valve start control signal is monitored directly at the output of the ABV regulation circuit.

If the ALB adjustment circuit itself is incorrect, the ALB-SIS
Excessive energization of the valve electromagnet for other reasons cannot be detected, since the interruption of the ABV-SIS due to this may be erroneous. In order to avoid this, measures according to claim 4 have been taken. In the unbraked state, ie Pe=0, the ABV-SIS interruption is interrupted by the ALB regulation circuit. In braking conditions, as is known
A signal t _v4 is generated by the ABV regulation circuit which indicates a reference for the response of the ABV regulation circuit. This signal likewise prevents the ABV-SIS from being interrupted, ie the ABV-SIS is reconnected. However, in this case, only signal t _v4 of the starting control signals from the ABV regulation circuit logic to the outlet valve may be used.

In order to avoid erroneous braking pressure regulation in the case of a fault in the ALB regulation circuit, embodiments of the invention provide that, in the event of an ALB-SIS fault signal, the ALB to inlet and outlet valves and ABV-SIS The starting control lead of the regulating circuit is suddenly severed.

The measures claimed in claim 6 have been taken so that the ALB regulation circuit can signal a fault characterized by failure to limit the rear axle braking pressure when it should have been activated. There is.

According to an embodiment of the invention, mutual monitoring of the ALB regulation circuit and the ALB safety circuit is achieved by providing a device for monitoring the coincidence of the outputs of the ALB regulation circuit and the comparison circuit of the ALB-SIS, which device notifies the discrepancy. It is done by doing.

A simple example of a safety circuit for an ALB regulator is that in the unbraked state (Pe=0) the ABV-SIS
The electromagnet energization time monitoring of the valve electromagnet can detect possibly erroneous starting control of the valve electromagnet in the ABV regulation circuit or
It is thought that it is possible to detect whether or not it is emitted from the ALB regulatory circuit. This is because the starting control of the electromagnet is performed both before and after the point of application of the ALB. The error detection allows the ALB regulation circuit to be disconnected, in which the control action of the conductors from gates 28 to 36 and from gates 26 to 34 is disabled.

The invention will be explained in more detail with reference to the accompanying drawings, in which examples of embodiments thereof are shown.

In Figure 1, reference numeral 2 indicates the detector, 4 indicates the ABV adjustment circuit, 6 indicates the ABV-SIS, and 8 indicates the ABV-SIS.
The ALB regulation circuit is also shown at 10, the ALB-SIS.

Terminal 1 for ALB adjustment circuit and ALB-SIS
Via 2, 14 and 16, the measured variables corresponding to the supply pressure Pe, the brake cylinder pressure Pz and the load L are supplied.

ALB-SIS includes a comparison for comparing the supply pressure Pe with the brake cylinder pressures Pz, Pe, Pz and for comparing the actual characteristic curve of the ALB regulator (Pz = f( _UL , Pe)) with the setpoint characteristic curve. equipment is provided. Here U _L is a measured value corresponding to the load and expressed, for example, in the form of a voltage.

The ALB-SIS has an error signal output conductor 18 which is led via an AND gate 20 to an error indicator 22.

ABV adjustment circuit and ABV-SIS are logic circuits 24
is coupled to the ALB regulatory circuit and ALB-SIS via. This logic circuit consists of two AND gates 2
6 and 28, and with these and gates
The output signals of the ALB adjustment circuit and ALB-SIS are combined. ALB-SIS error signal is AND gate 2
6 and 28 and the output signal of the ALB regulation circuit is led to the non-inverting inputs of these gates.

The logic circuit 24 has a further AND gate 30 with three inputs, one non-inverting input receiving the output signal of the ALB regulation circuit and the other inverting input receiving the error signal of the ALB-SIS. and comparison circuit 3
Two output signals are derived. The comparison circuit 32 asks whether the supply pressure Pe is zero (Pe=0).

Logic circuit 24 further includes two OR gates 34 and 36, into which the output signals of AND gates 26 and 28 and the ABV adjustment circuit are collected. The output of the OR gate 34 is passed through an amplifier 38 to trigger an inlet valve 40 (EV), and the output of the OR gate 36 is routed to an amplifier 42 to trigger an outlet valve 44 (AV).

The output of the AND gate 30 is connected to the non-inverting input of another AND gate 46, which has an inverting input to which the adjustment process instruction signal t _v4 of the ABV adjustment circuit is introduced. Via the AND gate 46, the ABV-SIS is activated and blocked by the ALB regulation circuit.

ABV-SIS 6 monitors the starting control time of the inlet valve and outlet valve electromagnets via conductors 48 and 50 and the output signal of the ABV regulation circuit before logical combination with the signal from the ALB circuit via conductors 52 and 54. do. The output signal of the ABV-SIS is directed to an ABV error indicator 56.

The circuit of FIG. 1 operates as follows.

1 The ALB regulation circuit operates normally, and therefore
ALB-SIS 10 does not generate an error signal, ABV adjustment does not proceed, and Pe=0, so first AND gate 26 and OR gate 34
The EV is blocked from the moment the desired pressure point K ₁ (FIG. 2) is reached via , and the further supply of pressure medium to the rear axle brake cylinder is interrupted (broken line regulator). When the supply pressure Pe decreases, through the AND gate 28 and the OR gate 36
Since the start of the AV is controlled in addition to the EV, the pressure inside the brake cylinder decreases. Due to the first condition listed, the signal applied to the inverting inputs of AND gates 30 and 46 is zero, and therefore the signal generated by ALB adjustment circuit 8 is:
Through these AND gates 30 and 46
Block ABV-SIS6. Due to this,
As a result of the normally relatively long valve electromagnet energization times during ALB adjustment, the ABV-SIS responds via the electromagnet energization time monitoring device, and incorrect braking behavior is avoided.

2 ALB-SIS is in an unacceptable state, e.g.
If, in the event of a fault in the ALB regulation circuit, the setpoint pressure in the brake cylinder, for example, is found to be outside the tolerance range monitored by the ALB-SIS, the SIS generates an error signal, which signals this condition. If ABV regulation is not progressing, t _v
4 , via device 22 and on the other hand, by blocking AND gates 26, 28 and 30, the ABV-
Unblocks the SIS and also interrupts the starting control of the valve electromagnet. This allows the brake cylinder pressure to be lowered again and the electromagnet energization time monitoring to be canceled again.

3 For example, if the ALB adjustment circuit itself is incorrectly connected, there is a possibility that the ALB is incorrectly interrupting the ABV-SIS both in the non-braking state and in the braking state, so the valve electromagnet may be energized for too long for some reason. can't know.
In that case, in the unbraked state the supply pressure Pe
=0. In that case, the comparator circuit 32 is “L”
A signal is issued, which blocks the AND gate 30, thereby terminating the interruption of the ABV-SIS. In the damped adjustment state, the ABV adjustment circuit generates a signal t _v4 indicating adjustment, which blocks the AND gate 46 and thereby also unblocks the ABV-SIS. However, in this case, the signal t out of the starting control signal for the outlet valve
Only _v4 may be used from ABV logic circuits.

4 If the ALB-SIS finds, by comparison of the values of the actual and target characteristic curves of the ALB regulator, that the actual value is outside the predetermined tolerance range of the target value (U _pz > U(L)), then the ALB-SIS SIS generates an error signal,
This signal signals an error via device 22 and also blocks AND gates 26, 28 and 30 as in the case of the error mentioned in the second point. This avoids errors, which are characterized by the fact that the rear axle brake pressure is not limited when the ALB regulation should be activated, so that a completely different braking behavior than usual occurs. This error case is explained in more detail in FIGS. 2 and 3.

In FIG. 3, reference numerals 60, 62 and 64 indicate measurement value transmitters for supply pressure Pe, brake cylinder pressure Pz and load _FL . The output quantity of these measurement value transmitters, for example in the form of voltage, is
It is also led to the ALB adjustment circuit 66 and to the ALB-SIS 68. Now, the ALB-SIS shows by way of example a safety circuit for the simple case of a linear regulator, the characteristic curve of which is shown in FIG. The ALB-SIS has two comparison circuits 70 and 72 which compare the measured values of supply pressure and brake cylinder pressure and the measured values of brake cylinder pressure and load with each other. A comparator circuit 70 provides a signal if the brake cylinder pressure is greater than the supply pressure, and a comparator circuit 72 provides a signal if the brake cylinder pressure measurement deviates from the load measurement by a predetermined amount, i.e. when the ALB regulator A signal is issued if the actual characteristic curve lies outside a predetermined tolerance range of the desired characteristic curve of the ALB regulator. The output signal thus representing the error signal is transmitted to timing elements 74 and 7.
6, they are collected at the OR gate 78 and each error is reported via the alarm device 80.
This alarm device can also be activated by ABV-SIS (not shown). The output signal of ALB regulation circuit 66 triggers and controls the inlet and outlet valve electromagnets (EV and AV).

Example: The pressure in the rear axle brake cylinder is the characteristic curve P.
_z1 (see FIG. 2), the inlet valve is activated from point _K1 and the subsequent pressure build-up takes place in stages. Now ALB-SIS
performs a comparison between the actual value and the target value within the tolerance range indicated by the dashed line. If the actual pressure value is outside this range, an error exists and the ALB-SIS signals this event on the monitoring device.

The main monitoring criterion is thus the simulation of the accommodation characteristic curve with widened tolerance ranges.

The ABV-SIS typically monitors the solenoid valve start control time after the amplifier stages 38 and 42 via leads 48 and 50. In order to be able to continue to monitor the ABV electronic circuit during operation of the ALB regulating circuit, a circuit is provided for monitoring the valve starting control signal of the ABV regulating circuit directly at the output of the ABV regulating circuit, i.e. via conductors 52 and 54. .

Multiple adjustment devices such as individual wheel adjustment, diagonal adjustment, etc. can be used for anti-stick vehicle braking systems. In the case of individual wheel adjustment with the ABV adjustment circuit and axle adjustment with the ALB adjustment circuit, the ALB-SIS must be disconnected if one wheel is adjusted with the ABV adjustment circuit. Since two pressure transducers are required for each wheel in this case, the corresponding measuring channels must also be disconnected.

As an example, an analog implementation of the circuit device according to the present invention has been described above with reference to FIGS. 1 to 3. A digitally realized example will be described below with reference to FIGS. 4 to 6. This is important in view of the large-scale integration of electronic devices and the associated digitization of electronics.

FIG. 4 generally shows a circuit for digitally realizing the actual value/setpoint value comparison in the ALB-SIS in order to prevent malfunctions of the adjustable vehicle braking system, for example in the event of a failure of the ALB regulating circuit. There is.

For example brake cylinder pressure in the form of voltage values
After analog measurement of Pz, supply pressure Pe and axial load or load F _L and after A-D conversion (digitization) in an A-D converter, not shown,
Binary digital words are generated as output quantities for analog measured values, and these digital words are connected to conductor 9.
0, 92 and 94 to memories 96, 98 and 100.

The digital words for Pe and F _L are used to address the read memory 102, which provides specific output information via output leads 104 in relation to each input address. The output information indicates the setpoint value (B _{p .} . . B _k ) of the pressure to be set in the rear axle brake cylinder depending on the setpoint characteristic curve of the ALB regulator. This setpoint value is passed in the form of a digital word to a digital quantity comparison circuit and is compared there with the digitized measured value (A _p . . . A _k ) representing the actual value of the brake cylinder pressure.

If the actual data word (actual value) A is smaller than the reference data word (reference value or target value) B, then (A<
B), neither valve electromagnet is energized. A=B
If so, the inlet valve electromagnet EV is energized and A>B
If so, the inlet and outlet valve electromagnets (EV and AV) are energized.

To realize other characteristic curves, it is only necessary in the present case to change the programming of the reading memory, which is shown schematically in FIG. The digital control unit shown in FIG. 5 includes inter alia a memory and a digital comparator circuit according to FIG.

Since the ALB regulation concept allows relatively large quantization steps throughout, 6 bits are sufficient to represent the entire braking pressure range of about 0 to 7 kg/cm ² . The same holds true for the pressure in the rear axle brake cylinder and for the voltage related to the axle load.

Commercially available programmable memory is, for example, ²⁰ to ^27.
= has an address range of 1 to 127. The pressure Pe now supplied is a 5-bit value, and the axial load is 3.
Can be divided into bit values. The pressure Pe can thus be divided into 32 ranges and the axial load into 8 ranges. Both measurements represent a total of 8 bit data words. Depending on the range of Pe and U _L , a bit combination is obtained which addresses the associated desired rear axle pressure Pz and which is also available as setpoint value at the readout memory output.

Example: Pe=6Kg/cm ² U _L =3000Kg Pz=f(Pe, U
_L ) = 3.5Kg/cm ² The maximum shaft load is, for example, 10000Kg. In this case, for example, an axle load quantization step of 1000 kg is obtained. In this case, the pressure quantization step P _Q is P _Q = Pe・max/2 ⁵ = 7 bar/32 = 0.22 Kg/c
m ² In this case, 6Kg/cm ² corresponds to approximately 27×0.22=11011, and 3000Kg corresponds to the number sequence 011 in binary notation.

In this case, the resulting data word of target value B is B=11011/011. In this case, a digital value for 3.5Kg/cm ² has been written to this address. When a 1-bit word is generated from read memory, there is a quantity 3.5/0.22=15.9≒16
=1000 is written.

Actual value of brake cylinder pressure Pz now A _pz =
If 1001, then A>B or Pz>Psoll (here
Psoll is the pressure target value). In this case, both the inlet and outlet valve electromagnets must then be energized.

If we want to obtain a higher resolution for the pressure and load ranges, we have to use a reading memory (permanent storage memory) with an address range larger than ²⁷ . At the current state of the art, memories with addresses in the range ²⁰ to ²¹⁰ are commonly used, which corresponds to a memory capacity of 2048 bytes (8-bit words). Thereby, for example, a pressure range of 7 kg/cm ² becomes a quantization step of 0.22 kg/cm ² again,
Also, the load range can be set in quantization steps of 312Kg=300Kg.

One way to improve quantization is to use 1/4K memory (4 bits), which is outlined in FIG. Each measured quantity (pressure,
The entry address of the memory is formed from the load or load) and then the programmed output bit combination (4 bits) is transferred to another memory (256
8), whose output word represents the target value of pressure.

[Brief explanation of the drawing]

1 is a block diagram of the safety circuit according to the invention; FIG. 2 is a diagram showing the desired characteristic curve of a load-related braking pressure regulator, that is, a simple linear linear regulator;
Figure 3 is a schematic diagram of ALB-SIS in an analog configuration for the case of a polygonal regulator according to Figure 2;
The figure shows a block circuit diagram for simulating the ALB regulator characteristic curve in a digital configuration, for example for comparison of actual values and setpoint values in the ALB-SIS. The figure is a block circuit diagram for improving quantization. 2...Detector, 4...ABV adjustment circuit, 6...
ABV-SIS, 8...ALB adjustment circuit, 10...ALB
-SIS, 24...logic circuit, 40...inlet valve, 4
4... Outlet valve.

Claims (1)

[Scope of Claims] 1 (a) Anti-sticking control that receives and evaluates information regarding changes in the rotational speed of the wheel via a sensor located on the wheel and controls the activation of the solenoid valves, that is, the inlet and outlet valves that regulate the braking pressure. (b) receives and evaluates information regarding the supply pressure Pe, brake cylinder pressure Pz, and load U _L supplied from the brake valve via the measurement value transmitter, and controls the solenoid valve. (c) The output terminal of the ABV regulation circuit and the output terminal of the ALB regulation circuit are logically coupled to each other via a logic circuit to control the braking pressure regulating circuit (ALB regulation circuit) related to the load; (d) A safety circuit for the ABV regulation circuit (ABV-SIS) that generates an error signal if the ABV regulation circuit does not operate regularly; and (e) a safety circuit for the ALB regulation circuit 8 (ALB-SIS). SIS)1
(f) ALB adjustment circuit 8, ABV adjustment circuit 4 and
ALB-SIS10 and ABV-SIS6 are logic circuit 2
4 to each other and to the inlet and outlet valves 40 and 44, (g) in the case of anti-sticking braking force regulation (ABV regulation), the error signal of the ALB-SIS 10 is prevented, and (h) the load If the braking force adjustment (ALB adjustment) related to the ALB adjustment is carried out, but the ABV adjustment is not carried out at the same time, the signal generated by the ALB adjustment circuit 8 will cause the ABV-SIS 10 to generate an error signal. Safety circuit in an anti-sticking and load-dependent adjustable vehicle braking system, characterized in that SIS6 is blocked. 2. The ALB-SIS 10, 68 has a comparison circuit 70 that compares the supply pressure Pe and the brake cylinder pressure Pz, and if this comparison circuit indicates that Pe<Pz, the ALB adjustment circuit 8, 66 starts the electromagnets of the inlet and outlet valves. 2. Safety circuit according to claim 1, characterized in that the control is interrupted. 3 During ALB adjustment, the start control signal for the inlet and outlet valves generated by the ABV adjustment circuit 4 is
ABV-SIS6 before interference by ALB adjustment circuit 8.
Safety circuit according to claim 1, characterized in that it is monitored by a. 4. Ensure that the blocking conductor from the ALB regulation circuit 8 to the ABV-SIS 6 is immediately severed when the supply pressure Pe = 0 (unbraked state) and when the signal indicating ABV regulation (signal t _v4 ) occurs. A safety circuit according to claim 1, characterized in that: 5 In the event of an error signal of the ALB-SIS 10, the inlet and outlet valves 40, 44 and the ABV-SIS 6
2. Safety circuit according to claim 1, characterized in that the starting control conductor of the ALB regulating circuit 8 to the ALB control circuit 8 is cut off. 6 ALB-SIS10, 68 compares the measured quantity U _pz (actual value) corresponding to the brake cylinder pressure Pz with the measured quantity U _L (reference value) corresponding to the load, and calculates (U _pz
= U _L ) a further comparator circuit 72 for comparing the values of the actual characteristic curve with the values of the reference characteristic curve of the ALB regulator by generating an error signal in the event of exceeding the reference value or the reference value tolerance range. A safety circuit according to claim 1, characterized in that the safety circuit comprises: 7. Safety according to claim 1, characterized in that a device is provided for monitoring the coincidence of the outputs of the ALB adjustment circuit and the comparison circuit of the ALB-SIS, and this device generates a signal in the event of a mismatch. circuit. 8. In order to prevent the error signal of ALB-SIS 10 during the ABV adjustment process, the non-inverting input terminal connected to the output terminal of ALB-SIS 10 is connected to the ABV adjustment circuit 4 and a signal t _v4 indicating the ABV adjustment process is introduced. 2. The safety circuit according to claim 1, characterized in that it is implemented by an AND gate having an inverting input. 9 A non-inverting input terminal connected to the ALB adjustment circuit 8 and a signal t indicating the adjustment process, in order to prevent the error signal of ABV-SIS when ALB adjustment is performed but ABV adjustment is not performed at the same time. for _v4
2. Safety circuit according to claim 1, characterized in that an AND gate (46) is provided, which has an inverting input connected to the output of the ABV adjustment circuit (4). 10 The means for cutting off the blocking conductor is provided by supply pressure.
An AND gate 30 having an inverting input terminal connected to the output terminal of the Pe monitoring or measuring device 32 and a non-inverting input terminal connected to the output terminal of the ALB adjustment circuit 8; 5. Safety circuit according to claim 4, characterized in that it consists of a further AND gate (46) having a non-inverting input and an inverting input connected to the output of the ABV regulation circuit (4). 11 Means for blocking the starting control leads to the inlet and outlet valves 40, 41 are provided at the non-inverting input end connected with the output end of the ALB regulating circuit 8 and the inverting input end respectively connected with the output end of the ALB-SIS 10. two AND gates 26 and 28 with
and means for blocking the starting control line to the ABV-SIS 6 are connected to the monitoring or measuring device 32 of the supply pressure Pe and to the output of the ALB-SIS 10, respectively, and the inverting input and the output of the ALB regulating circuit 8. 6. The safety circuit according to claim 5, characterized in that it comprises an AND gate 30 having a non-inverting input terminal connected to the AND gate 30.