FILL LEVEL MONITORING

Abstract

A method and an assembly for monitoring the fill level of a sandbox in a sanding system of a rail vehicle. The sandbox is connected to a pipe via a sand-conveying system. The sand-conveying system is controlled with a compressed air pulse in such a way that, with each compressed air pulse, a known quantity of sand is extracted from the sandbox and delivered in the form of a sand/compressed air mixture via the pipe into a wheel-rail gap of the rail vehicle. A control system of the rail vehicle determines a number of compressed air pulses used for operation, determines the quantity of sand applied by way of the number of compressed air pulses, and determines the current sand fill level of the sand container based on a previously known sand fill level of the sand container and the quantity of sand applied.

Claims

1-10. (canceled)

11. An assembly for monitoring the fill level of a sandbox of a sanding system in a rail vehicle, the assembly comprising: a sanding system arranged in an autonomously operated rail vehicle with no driver, said sanding system having a sandbox, a sand-conveying system, and a pipeline; wherein said sandbox is connected to said pipeline via said sand-conveying system; said sand-conveying system being configured for activation by a compressed-air pulse, wherein an already known amount of sand is removed from the sandbox per the compressed-air pulse and passes into a wheel-rail gap of the rail vehicle in a sand-and-compressed air mixture via said pipeline; and a process controller connected to a stationary process control station and configured to display a current sand fill level at the process control station and to identify faults at the sanding system by inference from a reduced or an increased use of sand during an operation of the rail vehicle.

12. The assembly according to claim 11, wherein said process controller is connected to a controller that is configured to form the compressed-air pulses for said sand-conveying system based on a request.

13. The assembly according to claim 11, wherein said process controller is connected to an operating unit of the rail vehicle SFZ, and the operating unit is configured to display: at least one of an amount of sand which is still available or a current fill level of the sandbox; and/or a range of the rail vehicle remaining in view of the current sand fill level of the sandbox.

14. A method for monitoring the fill level of a sandbox of a sanding system, the method which comprises: providing an assembly with a sanding system of a rail vehicle which is operated autonomously without a driver, and the sanding system has a sandbox, a sand-conveying system, and a pipeline, and wherein the sandbox is connected to the pipeline via the sand-conveying system; selectively activating the sand-conveying system by a compressed-air pulse to remove an already known amount of sand from the sandbox per compressed-air pulse and to pass the sand into a wheel-rail gap of the rail vehicle in a form of a sand-and-compressed air mixture via the pipeline; using a process control system of the rail vehicle to determine a number of the compressed-air pulses used for the activation, to determine an amount of sand dispensed via the number of the compressed-air pulses, and, starting from an already known sand fill level of the sandbox and the amount of sand dispensed, to determine a current sand fill level of the sandbox; communicating remaining amounts of sand remaining at the rail vehicle from the process control system via a remote connection to a landside process control station in order to display the current sand fill level at the landside process control station; and identifying faults at the sanding system by inference from a reduced or increased application of sand during an operation of the rail vehicle.

15. The method according to claim 14, which comprises calculating an amount of sand M.sub.EPv which is removed from the sandbox and is dispensed into the wheel-rail gap as follows: $M_{\mathrm{EPv}}=\underset{k=1}{\overset{n_{\mathrm{ges}}}{.Math.}}\left(\frac{t_p}{t_i}*m*t_{\mathrm{sk}}\right)$ where: n.sub.ges is a total number of sanding procedures or the number of compressed-air pulses; t.sub.sk is a duration of a sanding procedure; t.sub.p is a duration of a compressed-air pulse; t.sub.i is a time interval between two successive compressed-air pulses; m is an amount of sand dispensed per pulse.

16. The method according to claim 14, which comprises, starting from the determined sand fill level of the sandbox and starting from an already known average consumption of sand per unit of distance traveled for the rail vehicle, calculating a prediction is calculated of for how many unit of distance of travel there is still enough sand, wherein the prediction represents a remaining travel time of the rail vehicle.

17. The method according to claim 16, which comprises communicating amounts of the sand consumed by the rail vehicle or a remaining travel time of the rail vehicle from the process control system via a suitable remote connection to a landside process control station.

18. The method according to claim 17, which comprises optimizing the prediction of the remaining travel time for maintenance which is to be performed by taking into account by the process control station weather forecasts and/or route topologies.

19. The method according to claim 18, which comprises transmitting the optimized prediction of the remaining travel time to the rail vehicle in order to display the data in the vehicle.

Description

[0037] The invention will be explained in detail below with the aid of drawings, in which:

[0038] FIG. 1 shows an exemplary embodiment of the invention,

[0039] FIG. 2 shows, with reference to FIG. 1, a characteristic curve of activation of a valve, and

[0040] FIG. 3 shows, with reference to FIG. 1 and FIG. 2, an associated flow chart.

[0041] FIG. 1 shows an exemplary implementation of monitoring according to the invention of the fill level of a sandbox of a sanding system of a rail vehicle. For a first driving direction FR1 of the rail vehicle SFZ, sand SA is conveyed from a first sandbox SB1 by means of compressed air via a first sand-conveying system SFS1 and passes as a sand/compressed air mixture SA via a pipeline into a wheel/rail gap RSSP in front of wheels of a driven first axle A1.

[0042] For a second driving direction FR2 of the rail vehicle SFZ, sand SA is conveyed from a second sandbox SB2 by means of compressed air via a second sand-conveying system SFS2 and passes as a sand/compressed air mixture SA via a pipeline RL into a wheel/rail gap RSSP in front of wheels of a driven second axle A2.

[0043] The compressed air is, for example, blown into an outlet region of the sandbox SB1, SB2 or into the respective sand-conveying system SFS1, SFS2 and mixes there with a defined amount of sand.

[0044] The compressed air required to convey the sand SA and to dispense the sand into the wheel/rail gap RSSP is provided with the aid of a compressed-air supply DVS.

[0045] The compressed-air supply DVS is connected to both sandboxes SB1, SB2 via a shut-off valve AB1 and via respective compressed-air lines. The shut-off valve AB1 ensures that the sanding system can be manually disconnected from the compressed-air system in the event of leaks or faults.

[0046] Sanding via the first sandbox SB1 or via the second sandbox SB2 is selected with the aid of electropneumatic valves EP1, EP2 which ensure the selective supply of compressed air to one of the two sandboxes SB1, SB2 or to one of the two sand-conveying systems SFS1, SFS2.

[0047] To do this, a first valve EP1 is connected between the compressed-air supply DVS and the first sand-conveying system SFS1, whilst a second valve EP2 is connected between the compressed-air supply DVS and the second sand-conveying system SFS2.

[0048] If, for the first driving direction FR1, the sanding is made via the first sandbox SB1, the first valve EP1 is opened and the second valve EP2 is closed. As a result, compressed air passes from the compressed-air supply DVS to the first sand-conveying system SFS1.

[0049] If, for the second driving direction FR2, the sanding is made via the second sandbox SB2, the second valve EP2 is opened and the first valve EP1 is closed. As a result, compressed air passes from the compressed-air supply DVS to the second sand-conveying system SFS2.

[0050] The two valves EP1, EP2 are activated via signals STSIG of a controller ST depending on the driving direction FR1, FR2.

[0051] The sand is discharged with the aid of signal pulses of the signals STSIG which are generated via the controller ST.

[0052] Vehicle parameters FPAR, for example a vehicle speed v and the desired driving direction FR1, FR2, are fed to the controller ST in order to control the amount of sand discharged.

[0053] A discharge of sand triggered by the controller ST is prompted via a sanding request ANF which acts on the controller ST.

[0054] The sanding request ANF is triggered manually by a driver of the vehicle, automatically by a drive/braking system of the rail vehicle, or by other systems of the rail vehicle.

[0055] The controller ST generates the control commands STSIG for the two valves EP1, EP2 on the basis of the request ANF, the vehicle speed v, and the driving direction FR1, FR2.

[0056] The controller ST can here be integrated completely or partially into the process control system LT of the vehicle.

[0057] The control commands STSIG are configured in the form of pulses and as modifiable. On the basis of the depicted system configuration, a corresponding amount of sand is removed from the sandboxes SB1, SB2 by the control commands STSIG and is introduced into the wheel/rail gap RSSP at predetermined time intervals in a predetermined amount.

[0058] The amount of the sand dispensed can be fixed by the pulse-shaped modifiable control commands STSIG. This will be described below in detail on the basis of FIG. 2.

[0059] The controller ST is connected to a process control system LT of the rail vehicle SFZ which is provided or used to control the rail vehicle SFZ.

[0060] A last filling procedure of the sandboxes SB1, SB2 is saved (for example in the form of a piece of data) in the process control system LT.

[0061] With the aid of the process control system LT, as described below a sand consumption is calculated and a prediction made about a remaining operating time or a remaining range of the rail vehicle with regard to a fill level of the sandboxes SB1, SB2 of the sanding system.

[0062] The process control system LT is connected to an operating unit BE of the rail vehicle SFZ.

[0063] Displayed to a driver of the vehicle with the aid of the operating unit BE are [0064] a still available amount of sand or the fill level of the sandboxes SB1, SB2, or [0065] a still remaining range or a still available operating time of the rail vehicle SFZ.

[0066] The inputting of the last filling procedure, which is used by the process control system LT, is also made possible with the aid of the operating unit BE.

[0067] The process control system LT is connected to a stationary control station or process control station LS, referred to as the landside.

[0068] A sand fill level of a predetermined rail vehicle, or sand fill levels for rail vehicles of a fleet, is or are collected, documented, and possibly displayed there.

[0069] This makes it possible to refill the sand as part of maintenance on the landside in a coordinated fashion or to plan journeys depending on current sand fill levels in an optimized fashion.

[0070] Correspondingly, information for refilling sand is input via the process control station LS and is then transmitted to an associated rail vehicle.

[0071] FIG. 2 shows, with reference to FIG. 1, activation of one of the two valves EP1, EP2, whilst FIG. 3 shows, with reference to FIG. 1 and FIG. 2, details of the invention in a flow chart.

[0072] The activation shows, plotted against time t, a control signal STSIG of the valve with a plurality of pulses 1 to n.

[0073] The pulses 1 to n have a duration t.sub.p and describe together a sanding procedure of the duration t.sub.s.

[0074] The pulses have two states, on and off. During the on state, the conveying and dispensing of sand, assisted by compressed air, take place, whereas these stop in the off state.

[0075] A defined amount m of sand is dispensed per pulse. It is ensured by the construction of the sanding system that the amount m dispensed is proportional to the duration of the pulses.

[0076] Two successive pulses have a defined time interval of duration t.sub.i.

[0077] The ratio between the durations t.sub.p and t.sub.i can be set such that an amount m of sand dispensed per unit time can be influenced and known in advance.

[0078] In a first step S1, a calculation of a consumed or dispensed amount of sand M.sub.EP is performed with the aid of the process control system LT.

[0079] The amount of sand M.sub.EP of the sand dispensed per sanding procedure t.sub.s depends on: [0080] the duration of the respective sanding procedure t.sub.s, [0081] the ratio between the durations t.sub.p and t.sub.i, [0082] an average amount m of the sand dispensed per unit time in the case of continuous activation with no pulses, expressed in units of g/s.

[0083] Thus, for the amount of sand M.sub.EP, which has been consumed since the associated sandbox SBv was last filled at a valve EPv (where v=1,2, etc, i.e. v designates a number of valves at the sandbox in question):

[00001]$M_{\mathrm{EPv}}=\underset{k=1}{\overset{n_{\mathrm{qes}}}{.Math.}}\left(\frac{t_p}{t_i}*m*t_{\mathrm{sk}}\right)$

where: [0084] n.sub.ges is the total number of sanding procedures at the valve EPv, [0085] t.sub.sk is the duration of the sanding procedure at this valve.

[0086] If precisely one valve EPv is installed at each sandbox SBv, the amount of sand M.sub.EPv is equal to the consumption of the sandbox SBv.

[0087] This is assumed for the method described here.

[0088] If this is not the case on a rail vehicle in question and a plurality of valves are associated with a sandbox there, the number of the respective valves must correspondingly be taken into account for the calculation.

[0089] The total amount M.sub.ges of sand consumed per rail vehicle can then be found from the sum of the amounts of sand over all

[00002]$M_{\mathrm{ges}}=\underset{v=1}{\overset{z_{EP}}{.Math.}}{M}_{\mathrm{EPv}}$ [0090] where Z.sub.EP is the total number of valves at the sanding system of the vehicle.

[0091] In a second step S2, calculation of a remaining amount of sand is performed.

[0092] The remaining amounts R.sub.EPV of sand per sandbox SBv are calculated by the process control system LT from the calculated consumptions M.sub.EPv and M.sub.ges, and a total remaining amount R.sub.ges of the vehicle is determined.

[0093] For this purpose, the process control system LT has stored the maximum filling amounts or the maximum fill levels per sandbox SBv.

[0094] The remaining amounts R.sub.EPv and R.sub.ges are calculated from the differences in the maximum filling amounts per tank M.sub.max and the calculated consumptions M.sub.EP, or the associated fill levels are calculated.

[0095] In a third step S3, a prediction of a remaining operating distance is determined or calculated.

[0096] On the basis of the calculated fill levels of the sandboxes and an already known average consumption d per kilometer traveled since the last time the sandboxes were filled, a prediction is calculated of for how many kilometers there is still enough sand.

[0097] This is calculated per sandbox SBv or per sand valve EPv as follows:

[0098] First, the average consumption per valve is calculated as follows:

[00003]$d_{\mathrm{EPv}}=\frac{M_{\mathrm{EPv}}}{w_{\mathrm{zur}}}$ [0099] where w.sub.zur is the distance traveled of the rail vehicle since the last time the sand was refilled.

[0100] If the average consumption w.sub.zur falls below a settable mini-mum value, for example 100 km, the calculation of d.sub.EPV is not performed. In this case, a settable standard value is assumed, for example an average value before the last refill.

[0101] A predicted remaining distance S.sub.RestEPv of the respective sandbox SBv at the valve EPv is calculated as follows:

[00004]$s_{\mathrm{RestEPv}}=\frac{R_{\mathrm{EPv}}}{d_{\mathrm{EPv}}}$

[0102] In order to take into account different types of usage of the vehicle (during, for example, a change in the driving direction and the associated switchover of the sanding system), in addition to the remaining distances S.sub.RestEP of the individual sandboxes SB, a remaining distance for the average consumption of the whole vehicle is calculated:

[00005]$s_{\mathrm{RestGes}}=\frac{R_{\mathrm{ges}}}{d_{\mathrm{ges}}}$$\mathrm{where}{d}_{\mathrm{ges}}=\frac{M_{\mathrm{ges}}}{w_{\mathrm{zur}}}$

(calculated analogously to d.sub.EPv)

[0103] In a fourth step S4, generation and communication of a warning are performed.

[0104] If the remaining amounts R.sub.EPv, R.sub.ges or the remaining distances S.sub.RestEPv, S.sub.RestGes fall below settable threshold values, the process control system LT generates a warning and sends it via a radio link to the process control station LS where it can be accessed by maintenance staff.

[0105] Additionally or optionally, the warning is displayed at the operating unit BE of the rail vehicle.

[0106] In a fifth step S5, display and communication of the calculated values are performed.

[0107] The amounts of the sand consumed M.sub.EPv and M.sub.ges and the remaining amounts R.sub.EPV and R.sub.ges are communicated as values from the process control system LT via a suitable remote connection to the process control station LS which stores this data for all the rail vehicles and allows it to be used by the maintenance staff.

[0108] Additionally or optionally, the values are displayed via the operating unit BE of the rail vehicle.

[0109] In a sixth step S6, weather forecasts and route topologies are taken into account. The amount of sand consumed is generally dependent on the weather and the topology of the route traveled. The process control station LS therefore optionally uses further data for improving the accuracy of the values.

[0110] In order to calculate improved remaining operating distances and improved remaining amounts of sand, the process control station LS automatically takes into account available weather forecasts for the route to be traveled. In the case of poor weather conditions, a higher consumption of sand is to be expected, which is taken into account in the calculation by a suitably chosen factor.

[0111] The route topology of the route to be traveled is likewise taken into account via a suitably chosen factor. The calculation of the improved remaining distance S.sub.VerbRestEPv per valve is then made by:

[00006]$s_{\mathrm{VerbRestEPv}}=s_{\mathrm{RestEPv}}*{}_{\mathrm{Wetter}}{}_{\mathrm{Strecke}}$

where .sub.Wetter is a factor which is dependent on the weather forecast for the planned route, and .sub.Strecke is a factor which depends on the route topology.

[0112] The improved value for S.sub.RestGes is calculated analogously.

[0113] The values thus improved for the remaining operating distances are stored in the process control station LS and made available to the maintenance staff.

[0114] The warning described in step S4 is calculated process control station LS based on the improved values. Additionally or optionally, the improved remaining operating distance or remaining amounts of sand thus calculated are made available to the vehicle via the remote connection for display at the operating unit BE.

[0115] In a seventh step S7, data is input relating to a sand refill which has been undertaken.

[0116] When the sandboxes are refilled, the maintenance staff input this data via the operating unit BE at the vehicle for the process control system LT.

[0117] Alternatively or additionally, this data is input and stored on the landside. It is then made available by the landside process control station LS to the vehicle via the remote connection.

[0118] When the process control system LT and the process control station LS receive this data, they correspondingly reset all the calculated values and restart with the calculations according to the steps S3, S4, and S6.

[0119] The data relating to the filling procedure can here be input either per sandbox or across the board for the whole vehicle.

[0120] Alternatively or additionally, a check is made when the sandboxes are refilled as to whether the remaining amounts of sand in the tanks SBv correspond to the projected amounts R.sub.EPV to a plausible extent.

[0121] If there is a significant deviation between the individual sandboxes, it can be inferred that there is a fault in the sanding system.