Braking adjustment device, braking method and braking system for rail vehicles

Abstract

The invention relates to a brake adjustment device (2) for a rail vehicle, which has a deceleration target value (a set ) input terminal (21), for the deceleration actual value (a train ) and an output terminal (23) for a deceleration adjustment parameter value, wherein the deceleration adjustment parameter value (a out ) is regulated by the control unit in order to minimize the actual deceleration value (a train ) and the deceleration target value (a stet The brake adjustment device (2) is characterized in that a limiting device is provided, which limits the deceleration adjustment variable value (a) independently of the adjustment unit. out ), so that the deceleration adjustment parameter value (a out ) and the deceleration target value (a stet ) The deviation is at most a negative maximum adjustment travel (14) for smaller values ​​or at most a positive maximum adjustment travel (15) for larger values. The invention also relates to a braking method and a braking system for a rail vehicle.

Description

Technical Field

[0001] The invention relates to a brake adjustment device for a rail vehicle, a brake system for a rail vehicle having such a brake adjustment device, and an operating method for a brake system. Background Art

[0002] Braking systems for rail vehicles have friction brakes, such as disk brakes or shoe brakes, in addition to generator brakes and auxiliary brakes, such as eddy current brakes. Environmental influences, such as moisture, snow or ice in particular, reduce the friction coefficient of the friction pair of these brakes, i.e., the friction coefficient between, for example, brake lining and brake disk. In order to achieve a predictable braking result despite the variable friction coefficient, a control loop is used, which compares the required and expected deceleration of the rail vehicle with the actually achieved deceleration and then adjusts a control variable of the brake system, such as the braking force.

[0003] For example, a brake system with such a control device is known from document DE 10 2015 11 0 053 A1. In this system, the acceleration components of the rail vehicle are determined, wherein, as a feature, in addition to the longitudinal deceleration, the vertically acting deceleration is also determined in order to be able to take into account the effects of the hanging output force separately. Document DE 10 2011 052 545 B4 likewise describes a brake system with a brake control device, in which the deceleration actual value is redundantly measured and averaged in order to achieve increased safety for the correct functioning of the brake system.

[0004] Figure 5 The characteristics of a controlled system for a control circuit of such a regulated brake system according to the prior art are shown.

[0005] In this diagram, the advancing time t is shown on the horizontal axis and a predetermined target value, here a predetermined acceleration target value a, is shown on the vertical axis. set In curve 11, the braking system is shown as a function of time at the deceleration a to be assumed. set Curve 11 changes from the initial value a in two steps. set = 0 and rises through an intermediate value to the required maximum value of the deceleration to be achieved. Thus, a braking situation emerges in which a slight braking should be performed for a certain time and then a stronger braking should be performed.

[0006] A lower control limit 12 and an upper control limit 13 are plotted around the curve 11. The two limits 12, 13 indicate a control range within which a brake control device according to the prior art can modify the required deceleration in order to get as close as possible to the required deceleration according to the curve 11 with the actually measured deceleration. The situation shown results from the control behavior of the control unit of the control circuit, which is designed here as a proportional controller by way of example. The control limits 12, 13 correspond to a positive maximum control travel 14 or a negative maximum control travel 15, which is Figure 4 According to the prior art, for the proportional controller, the positive maximum adjustment path 14 and the negative maximum adjustment path 15 are equally high for the required deceleration value and correspond to a certain predefined percentage of the currently required deceleration value.

[0007] In practice, however, in particular under the environmental conditions mentioned at the outset (e.g. moisture, snow or ice between the friction pairs), effects may occur which can only be inadequately compensated for by the control circuit described. For example, the environmental influences mentioned have a stronger effect at low braking demands than at high braking demands. One reason for this is, for example, that during more intense braking, moisture evaporates by heating the friction pairs (energy input) and the damaging effects during braking are reduced ("dry brake" effect). Summary of the invention

[0008] The object of the present invention is to provide a brake control device, a brake system and an operating method for a brake system which achieve an optimal braking result even in the event of changes in the friction properties between the friction partners of the brake system, in particular in the event of changes in the friction properties caused by moisture, snow or ice.

[0009] The object is achieved by a brake control device, a brake system or an operating method for a brake system having the features described below.

[0010] A brake adjustment device according to the invention of the type described at the outset is characterized in that the brake adjustment device has an input for a deceleration target value and an input for an actual deceleration value and an output for a deceleration adjustment parameter value, wherein the deceleration adjustment parameter value is adjusted by a control unit in order to minimize the deviation between the actual deceleration value and the deceleration target value, and a limiting device is present independently of the control unit, which limits the deceleration adjustment parameter value in such a way that the deviation of the deceleration adjustment parameter value from the deceleration target value is at most a negative maximum adjustment stroke for a smaller value or at most a positive maximum adjustment stroke for a larger value.

[0011] The limiting device according to the invention makes it possible to control the positive maximum adjustment travel or the negative maximum adjustment travel independently of the selected adjustment characteristic of the adjustment unit. In this way, the optimal adjustment parameters can be selected at the same time and it can be ensured that no excessive adjustment travel occurs. In particular, the best braking results can be achieved under difficult conditions such as moisture and / or snow.

[0012] When using a brake control circuit with a proportional controller, according to the prior art, the following control characteristic is also obtained in principle, in which the maximum control stroke is limited. However, this characteristic is limited to the use of a simple proportional controller, the control characteristic of which is only inadequate. In addition, the inherent limitation of the control stroke set in this way is inflexible, because the maximum stroke in the positive and negative directions is proportional to the deceleration target value. However, this characteristic does not lead to the best braking result, especially in wet and / or snowy conditions. Therefore, in an advantageous design of the brake control device, at least one of the negative maximum control stroke and the positive maximum control stroke is selected so as not to be proportional to the deceleration target value.

[0013] In another advantageous embodiment of the brake adjustment device, the sum of the negative maximum adjustment travel and the positive maximum adjustment travel is a predetermined fixed value. The negative maximum adjustment travel can be selected to be different from the positive maximum adjustment travel. In this way, in particular at low deceleration target values, i.e. at low braking requirements, a higher braking force can be achieved, which results in a higher energy input, by which the reduced braking effect caused by moisture can be compensated and the brake system can be air-regulated.

[0014] In another advantageous embodiment of the brake control device, the positive maximum control stroke and / or the negative maximum control stroke are time-dependent, in particular such that they are reduced after a predetermined braking time. Thus, the maximum energy input into the brake can be limited and, for example, the effect of "dry braking" of the brake can be taken into account. It can be provided that the positive maximum control stroke is time-dependent only when the deceleration target value is below a predetermined limit value. Similarly, it can be provided that the negative maximum control stroke is time-dependent only when the deceleration target value is above another predetermined limit value.

[0015] In another advantageous embodiment of the brake adjustment device, at least one of the negative maximum adjustment stroke and the positive maximum adjustment stroke is predetermined by a characteristic curve or a characteristic curve family (or a characteristic curve field) associated with a deceleration target value and / or a braking time. In addition, at least one of the negative maximum adjustment stroke and the positive maximum adjustment stroke can be related to external influencing factors. External influencing factors can be (measured or otherwise determined) environmental conditions, such as temperature or humidity, or can also be driving conditions of the rail vehicle, in particular driving speed, brake pressure, braking force and / or activation of an anti-skid system and / or a sanding system and / or a magnetic rail brake.

[0016] In another advantageous embodiment of the brake control device, the limiting device is coupled to the control unit in order to act on a parameter of the control unit according to the limitation. In this way, a higher stability of the control loop can be achieved when the limiting device responds. If the control unit has an integral control component, for example, the integral value of the difference between the deceleration actual value and the deceleration target value can continuously increase (or decrease) further, while the limiting device has already limited the output deceleration adjustment variable value. In the case of a subsequent change in the braking situation, in which the deceleration adjustment variable value is not limited, an excessively large (or too small) adjustment variable value is output by the integral control component.

[0017] The brake system for a rail vehicle according to the invention is characterized by such a brake adjustment device. This results in the advantages described in conjunction with the brake adjustment device.

[0018] In the operating method of the braking system for rail vehicles according to the present invention, the deceleration adjustment parameter value is adjusted by the adjustment unit according to the deceleration target value and the deceleration actual value so as to minimize the deviation between the deceleration actual value and the deceleration target value. The method is characterized in that the deceleration adjustment parameter value is limited in such a way that the deviation of the deceleration adjustment parameter value from the deceleration target value can be at most a negative maximum adjustment stroke for a smaller value or a positive maximum adjustment stroke for a larger value. It is preferred that at least one of the negative maximum adjustment stroke and the positive maximum adjustment stroke is not proportional to the deceleration target value. It is further preferred that at least one of the negative maximum adjustment stroke and the positive maximum adjustment stroke is determined according to the deceleration target value and / or the braking time and / or the environmental conditions and / or the driving conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be described in detail below based on an embodiment with the aid of the accompanying drawings. The accompanying drawings show:

[0020] Figure 1 A block diagram showing a controlled system of a braking system;

[0021] Figures 2 to 4 respectively show diagrams for illustrating characteristics of a controlled system of a brake system according to the present application; and

[0022] Figure 5 A diagram is shown for illustrating the behavior of a brake system according to the prior art. DETAILED DESCRIPTION

[0023] exist Figure 1 1 shows a controlled system 1 of a brake system according to the present application in the form of a block diagram. The controlled system 1 comprises a brake regulating device 2, which predetermines a deceleration target value a via an input terminal 21. set . Deceleration target value a set The brake control device 2 has a second input 22, the actual value of the deceleration a which is actually measured. train is supplied to the second input. The measured deceleration actual value a train It may be provided, for example, by an acceleration sensor and / or by a GPS (Global Positioning System).

[0024] The brake control device 2 also has an output 23 at which a modified deceleration value is output as a deceleration adjustment variable a. out Next, combine the attached Figure 2 and 3 The exact function of the brake control device 2 is explained in more detail.

[0025] The deceleration adjustment parameter a output by the brake adjustment device 2 out is supplied to the input terminal 31 of the control variable converter 3. The control variable converter 3 is composed of the deceleration control variable a out The braking force F output at the output 32 is determined. The braking force F is a control variable for other components of the brake system. The braking force describes the force to be achieved cumulatively by the braking of the brake system and is also derived from the deceleration control variable a while taking into account the mass of the rail vehicle. out The value of the braking force F is transmitted via an input 41 to a distributor 4, which distributes the braking force to different axles and / or different brakes and / or different brake types of the rail vehicle and outputs the axle braking force F for different axles of the rail vehicle at corresponding outputs, in this case two outputs 42, 43, for example. axle 1 and F axle n .

[0026] Without the brake control device 2 according to the present application, the predetermined and to-be-achieved deceleration a can be setis directly connected to the input 31 of the manipulated variable converter 3. The manipulated variable converter outputs the braking force F in a controlled manner taking into account the mass of the rail vehicle. In the case shown, the braking force F is corrected by replacing the predetermined deceleration a to be achieved with set The deceleration adjustment parameter a out The correction value of is supplied to the control variable converter 3 which accordingly outputs the correction value of the braking force F. In an alternative embodiment of the brake system according to the present application, the control can also be based on the braking force F, wherein the braking force F is modified by a corresponding brake control device instead of the deceleration. However, the proposed system is advantageous in that when the control affects the deceleration target value, only one conversion must be performed while taking into account the vehicle mass, rather than a separate conversion for the control component of the pilot control.

[0027] Figure 2 As described at the beginning Figure 5 The same way is shown for the characteristics of the controlled system of the brake system according to the present application in the first embodiment. Figure 4 The same braking situation in which the required deceleration a set The adjustment is performed in two steps starting from the value 0. The lower and upper adjustment limits 12 , 13 and the respectively corresponding negative maximum adjustment travel 14 and positive maximum adjustment travel 15 are again plotted.

[0028] When adjusting the deceleration a set At a higher predetermined target value, the characteristic known from the prior art is shown, wherein the positive maximum adjustment stroke 14 and the negative maximum adjustment stroke 15 are the same size. Figure 2 The maximum deceleration value that can be required is shown in the right part of , and the adjustment paths 14 , 15 can also be selected to be as large as in the braking system according to the prior art.

[0029] However, at a smaller predetermined deceleration target value a set In the case of the lower and upper control limits 12, 13 (left part of the diagram), the spacing between the lower and upper control limits 12, 13 is also the same as the deceleration a in the right part of the figure. set Therefore, the width of the adjustment range is independent of the predetermined target value, that is, it is constant over the entire predetermined range. Figure 2It is also shown that, however, in the case of smaller predetermined values, the control range is divided into a positive maximum control path 15 and a negative maximum control path 14, so that there is a larger positive maximum control path 15. Therefore, the control range is not centered around the curve 11 in the case of smaller predetermined target values. The control behavior takes into account the fact that moisture can be detected disadvantageously right at the beginning of a braking process with smaller deceleration values, which can be compensated by the larger positive maximum control path 15.

[0030] By separating the control unit and the limiting device according to the present application, the type of control (eg proportional control and / or differential control and / or integral control) and the control parameters used can be selected completely independently of the control limits, ie the positive or negative maximum control travel 14 , 15 .

[0031] Figure 3 Another embodiment of the characteristics of the controlled system of the braking system according to the present application is shown. The diagram and the braking situation again correspond to the Figure 2 or Figure 5 The diagram and braking conditions described in .

[0032] In this example, the regulation limit is set when the braking demand is low (a set Hours) Figure 2 However, this is limited only in time, wherein, from a certain fixed defined time or dynamically calculated during the braking process, from the time in the transition region in Figure 2 The control limits 12, 13 shown in FIG. 1 are changed to Figure 4 In particular, the initially large positive maximum adjustment travel 15 is reduced to a smaller value of the negative maximum adjustment travel. This firstly achieves a favorable braking behavior in order to exclude moisture or similar environmental influences, but then ensures that the energy input is limited in the case of longer braking durations, which would otherwise occur in the case of overbraking.

[0033] This time-dependent behavior of the positive maximum adjustment path 15 can also be achieved in the negative maximum adjustment path 14. Figure 4 In the example of FIG. 1 , two adjustment paths 14 and 15 are shown to have a time correlation. Here, the time correlation itself is also shown in FIG. Figure 4 As shown in FIG, it can be different for the two adjustment paths 14, 15. The form of the time dependence can also differ from the linear time dependence shown here by way of example.

[0034] Here, Figures 2 to 4Only exemplary embodiments of control limits or control paths are shown, which are not generated strictly relative to a predefined deceleration target value, but are in another functional relationship to the predefined deceleration target value and / or are time-dependent.

[0035] It is understood that any functional relationship with a predetermined deceleration target value can be used. Here, the functional relationship is preferably optimized so that the best possible air conditioning effect of the friction pair is achieved under any desired deceleration when the braking effect is insufficient, for example drying the existing moisture.

[0036] The functional relationship or the characteristic curve obtained therefrom can also be additionally dependent on other influencing factors, for example on environmental conditions, such as temperature and / or humidity, and / or driving conditions, such as vehicle speed, wheel speed, brake pressure or brake force and / or the activity of an anti-skid system. Figure 3 and Figure 4 As shown in , a time function dependency can be introduced in order, for example, to limit the maximum energy input.

[0037] Reference numerals

[0038] 1 Controlled system

[0039] 11 Requirement curve

[0040] 12, 13 Adjustment limit

[0041] 14 minus maximum adjustment travel

[0042] 15 Positive maximum adjustment stroke

[0043] 2 Brake adjustment device

[0044] 21, 22 Input terminal

[0045] 23 Output

[0046] 3 Adjusting the parameter converter

[0047] 31 Input

[0048] 32 Output

[0049] 4 Distributor

[0050] 41 Input

[0051] 42, 43 Output terminal

[0052] a set Deceleration target value

[0053] a train Actual value of deceleration

[0054] aout Deceleration adjustment parameter

[0055] F Braking force

[0056] F axle 1-axis braking force

[0057] F axle n Axle braking force

Claims

1. A brake adjustment device (2) for a rail vehicle, the brake adjustment device having a deceleration target value (a set ) input terminal (21), for the deceleration actual value (a train ) and an input terminal (22) for adjusting a deceleration parameter value (a out ) output terminal (23), wherein, The deceleration adjustment parameter value (a out ) is regulated by the control unit in order to minimize the actual deceleration value (a train ) and the deceleration target value (a set ), characterized in that a limiting device is present which limits the deceleration adjustment variable value (a) independently of the control unit out ), so that the deceleration adjustment parameter value (a out ) and the deceleration target value (a set ) The deviation is at most the negative maximum adjustment travel (14) for smaller values ​​or at most the positive maximum adjustment travel (15) for larger values.

2. The brake adjustment device (2) according to claim 1, wherein: At least one of the negative maximum adjustment stroke (14) and the positive maximum adjustment stroke (15) is not equal to the deceleration target value (a set ) are proportional.

3. The brake adjustment device (2) according to claim 1 or 2, wherein: The sum of the negative maximum adjustment stroke (14) and the positive maximum adjustment stroke (15) is a predetermined fixed value.

4. The brake adjustment device (2) according to claim 1 or 2, wherein: The negative maximum adjustment stroke (14) is not equal to the positive maximum adjustment stroke (15).

5. The brake adjustment device (2) according to claim 1 or 2, wherein: The negative maximum adjustment travel (14) and / or the positive maximum adjustment travel (15) are time-dependent.

6. The brake adjustment device (2) according to claim 5, wherein: The negative maximum adjustment travel (14) and / or the positive maximum adjustment travel (15) is reduced after a predetermined braking time.

7. The brake adjustment device (2) according to claim 4, wherein: Only when the deceleration target value (a set ) is below a predetermined limit value, the positive maximum adjustment stroke (15) is only time-dependent.

8. The brake adjustment device (2) according to claim 5, wherein: Only when the deceleration target value (a set ) is below a predetermined limit value, the positive maximum adjustment stroke (15) is only time-dependent.

9. The brake adjustment device (2) according to claim 5, wherein: Only when the deceleration target value (a set ) is higher than another predetermined limit value, the negative minimum adjustment stroke (14) is only time-dependent.

10. The brake adjustment device (2) according to any one of claims 6 to 8, wherein: Only when the deceleration target value (a set ) is higher than another predetermined limit value, the negative minimum adjustment stroke (14) is only time-dependent.

11. The brake adjustment device (2) according to claim 1 or 2, wherein: At least one of the negative maximum adjustment stroke (14) and the positive maximum adjustment stroke (15) is determined by the deceleration target value (a set ) and / or a braking time-dependent characteristic curve or a characteristic curve family is predefined.

12. The brake adjustment device (2) according to claim 1 or 2, wherein: At least one of the negative maximum adjustment stroke (14) and the positive maximum adjustment stroke (15) is related to an external influencing factor.

13. The brake adjustment device (2) according to claim 12, wherein: The external influencing factors are environmental conditions.

14. The brake adjustment device (2) according to claim 12, wherein: The environmental condition is temperature or humidity.

15. The brake adjustment device (2) according to claim 12, wherein: The external influencing factors are the driving conditions of the rail vehicle.

16. The brake adjustment device (2) according to claim 12, wherein: The external influencing factors are the travel speed of the rail vehicle, the brake pressure, the braking force and / or the activation of the anti-skid system and / or the sanding system and / or the magnetic rail brake.

17. The brake adjustment device (2) according to claim 1 or 2, wherein: The limiting device is coupled to the regulating unit in order to act on a parameter of the regulating unit according to a limitation.

18. A method for operating a braking system for a rail vehicle, wherein: According to the deceleration target value (a set ) and the actual value of deceleration (a train ) Adjust the deceleration adjustment parameter value (a) through the adjustment unit out ) so that the actual deceleration value (a train ) and the deceleration target value (a set ), characterized in that the deceleration adjustment variable value (a) is limited independently of the control unit out ), so that the deceleration adjustment parameter value (a out ) and the deceleration target value (a set ) The deviation can be at most the negative maximum adjustment travel (14) for smaller values ​​or at most the positive maximum adjustment travel (15) for larger values.

19. The operating method according to claim 18, wherein: At least one of the negative maximum adjustment stroke (14) and the positive maximum adjustment stroke (15) is not equal to the deceleration target value (a set ) are proportional.

20. The operating method according to claim 18 or 19, wherein: According to the deceleration target value (a set ) and / or braking time and / or environmental conditions and / or driving conditions determine at least one of the negative maximum adjustment travel (14) and the positive maximum adjustment travel (15).

21. A brake system for a rail vehicle, comprising a brake adjustment device (2) according to any one of claims 1 to 17.

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