Sensor Cleaning System for Vehicles

Abstract

Sensor cleaning system for cleaning sensors, in particular vehicle sensors, and associated method, characterized by a liquid reservoir for holding a cleaning liquid, and including a control unit for activating a switch unit and including at least one nozzle for spraying at least one sensor, the switch unit being provided between the liquid reservoir and the at least one nozzle, a liquid line being provided between the liquid reservoir and the switch unit and at least one nozzle line being provided between the switch unit and the at least one nozzle.

Claims

1. Sensor cleaning system for cleaning sensors, comprising a liquid reservoir for holding a cleaning liquid, comprising a control unit for activating a switch unit and comprising at least one nozzle for spraying at least one sensor, the switch unit being provided between the liquid reservoir and the at least one nozzle, a liquid line being provided between the liquid reservoir and the switch unit and at least one nozzle line being provided between the switch unit and the at least one nozzle, characterized in that a gas reservoir fluidically connected to the liquid reservoir is provided for holding a cleaning gas, in that a gas line is provided between the gas reservoir and the switch unit, in that the cleaning liquid and the cleaning gas are pressurized during operation such that the cleaning liquid and/or the cleaning gas can be delivered toward the particular nozzle, and in that the switch unit is designed such that the at least one sensor can be cleaned via the at least one nozzle line by means of the cleaning liquid leaving the at least one nozzle and/or by means of the cleaning gas leaving the at least one nozzle.

2. Sensor cleaning system according to claim 1, characterized in that the switch unit can be controlled to switch positions by the control unit such that the at least one sensor can be sprayed over the duration of the switch position alternately with the cleaning liquid and the cleaning gas and/or pulsatingly with the cleaning liquid and/or the cleaning gas.

3. Sensor cleaning system according to claim 1, characterized in that a compressed gas source controlled by the control unit is provided for compressing the cleaning gas in the gas reservoir.

4. Sensor cleaning system according to claim 3, characterized in that the control unit controls the compressed gas source such that the gas reservoir is filled in accordance with the operating state of the vehicle.

5. Sensor cleaning system according to claim 1, characterized in that a common container is provided for holding the cleaning liquid and the cleaning gas.

6. Sensor cleaning system according to claim 5, characterized in that the container has an inlet for filling in the cleaning liquid and an inlet for filling in the cleaning gas or a common inlet for filling in the cleaning liquid and the cleaning gas as well as a filling level sensor, a quality sensor and/or a pressure sensor.

7. Sensor cleaning system according to claim 5, characterized in that a heat exchanger, which is operated electrically and/or using heat from a cooling circuit, is provided at the container.

8. Sensor cleaning system according to claim 1, characterized in that the switch unit comprises switch valves which can be controlled by the control unit, the switch valves being switchable to different switch positions, one switch position being provided as the closed position of the liquid reservoir and of the gas reservoir one switch position being provided for delivering the cleaning liquid, one switch position being provided for delivering the cleaning gas and one switch position being provided for delivering a mixture of cleaning liquid and cleaning gas.

9. Sensor cleaning system according to claim 1, characterized in that the control unit is designed such that the sensors can be cleaned at defined time intervals depending on the time of year, the weather and the vehicle location and/or based on a cleaning signal from the sensors to be cleaned and/or a dirt sensor on the sensor.

10. Method for cleaning sensors by spraying a sensor, characterized by the following method steps: a. providing pressurized cleaning liquid in a liquid reservoir; b. providing compressed cleaning gas in a gas reservoir; and at least one of the following: c1. alternately spraying the sensor with the cleaning liquid and the cleaning gas; and c2. pulsatingly spraying the sensors with the cleaning liquid and/or the cleaning gas.

11. Method according to claim 10, characterized in that the cleaning gas is compressed in accordance with the operating state of the vehicle and/or of the sensor cleaning system and/or the cleanliness of the sensors.

12. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In the drawings:

[0031] FIG. 1 is a schematic representation of the sensor cleaning system comprising the sensors to be cleaned;

[0032] FIG. 2 is a schematic representation of an alternative embodiment of the liquid reservoir and the gas reservoir;

[0033] FIG. 3a is a schematic representation of an alternative embodiment of the switch unit; and

[0034] FIG. 3b is a schematic representation of a further alternative embodiment of the switch unit.

DETAILED DESCRIPTION

[0035] The sensor cleaning system 10 shown in FIG. 1 for cleaning three sensors 16.1, 16.2, 16.3 shown in FIG. 1 comprises a liquid reservoir 12 for holding a cleaning liquid 14, a gas reservoir 28 for holding a cleaning gas 30, a switch unit 20, a control unit 22 for controlling the switch unit 20 and three nozzles 18.1, 18.2, 18.3 for cleaning the respective sensors 16.1, 16.2, 16.3. The liquid reservoir 12 is arranged in a liquid container 50A and the gas reservoir 28 is arranged in a gas container 50B.

[0036] An inlet 52 for filling in the cleaning liquid 14 and an outlet 56 for delivering the cleaning liquid 14 are provided at the liquid container 50A. A filling level sensor 60 and a switch valve 61 are provided at the inlet 52 such that the cleaning liquid 14 can be filled in manually or in an automated manner. The switch valve 61 can be controlled by the control unit 22. The output signals from the filling level sensor 60 are supplied to the control unit 22 to form a control loop.

[0037] An inlet 54 for filling in the cleaning gas 30 and an outlet 58 for delivering the cleaning gas 30 are provided at the gas container 50B. A compressed air pump 34 for compressing the cleaning gas 30 is provided at the inlet 54, and a pressure sensor 64 and a pressure-relief valve 68 are provided at the outlet 58. A quality sensor 62 is arranged at the liquid container 50A and a quality sensor 63 is arranged at the gas container 50B. The compressed air pump 34 is activated by the control unit 22; the output signals from the quality sensor 62 and from the pressure sensor 64 are communicated to the control unit 22 to form control loops.

[0038] A reservoir line 35 and a valve unit 36 are arranged between the liquid container 50A and the gas container 50B. The valve unit 36 can be switched to a switch position by the control unit 22 so that a fluidic connection can be established between the liquid reservoir 12 and the gas reservoir 28.

[0039] A liquid line 24 is arranged between the liquid container 50A and the switch unit 20 and a gas line 32 is arranged between the gas container 50B and the switch unit 20. The liquid line 24 is attached to the outlet 56 of the liquid container 50A and the gas line 32 is attached to the outlet 58 of the gas container 50B.

[0040] The control unit 22 controls the compressed air source 34 connected to the gas reservoir 28 such that the gas reservoir 28 is filled with the cleaning gas 30 in accordance with the operating state of the vehicle.

[0041] When the fluidic connection between the liquid reservoir 12 and the gas reservoir 28 is established via the reservoir line 35, both the cleaning liquid 14 and the cleaning gas 30 are supplied under excess pressure, i.e. pressurized, by the compressed cleaning gas 30 in the gas reservoir 28. The excess pressure allows the cleaning liquid 14 and the cleaning gas 30 to be delivered. The switch unit 20 is designed such that the sensors 16.1, 16.2, 16.3 to be cleaned can be cleaned by means of cleaning liquid 14 and/or cleaning gas 30 leaving the nozzles 18.1, 18.2, 18.3.

[0042] During operation, the cleaning gas 30 can be supplied in the gas container 50B under excess pressure by the activation of the air pressure source 34. The cleaning liquid 14 can be filled into the liquid container 50A via the inlet 52. By blocking the fluidic connection via the reservoir line 35 by switching the valve unit 36, it is possible to fill the cleaning liquid 14 into the fluid container 50A via the inlet 52 in a pressure-free manner.

[0043] FIG. 2 shows an alternative embodiment of the liquid reservoir 12 and the gas reservoir 28. In said figure, the cleaning liquid 14 and the cleaning gas 30 are supplied in a common container 50 so as to be adjacent to one another. The container 50 comprises an inlet 52 as a connection for filling in the cleaning liquid 14 and an inlet 54 as a connection for the compressed air source 34. Furthermore, an outlet 56 for connecting the liquid line 24 and an outlet 58 for connecting the gas line 32 are provided.

[0044] As is clear from FIG. 1, two nozzle lines 26.1A, 26.1B, 26.2A, 26.2B, 26.3A, 26.3B are arranged between the switch unit 20 and the three nozzles 18.1, 18.2, 18.3, which nozzle lines merge at the particular junction 86.1, 86.2, 86.3 and lead into the respective nozzles 18.1, 18.2, 18.3. The switch unit 20 can be switched by the control unit 22 such that a fluidic connection can be established between the liquid reservoir 12 or the gas reservoir 28 and the nozzles 18.1, 18.2, 18.3.

[0045] The switch unit 20 can be controlled to various switch positions by the control unit 22. The cleaning mode for cleaning the sensors 16.1, 16.2, 16.3 is set by controlling the switch position and its duration. The sensors 16.1, 16.2, 16.3 to be cleaned can thus be sprayed alternately with the cleaning liquid 14 and the cleaning gas 30 and/or pulsatingly with the cleaning liquid 14 and/or the cleaning gas 30.

[0046] A heat exchanger 66, which is in particular operated electrically and/or using heat from a cooling circuit, can be provided at each of the containers 50, 50A, 50B.

[0047] Various embodiments of the switch units 20, 120, 220 are shown in FIGS. 1, 3 and 4. The switch units 20, 120, 220 comprise switch valves 80.1A, 80.1B, 80.2A, 80.2B, 80.3A, 80.3B, 180.1, 180.2, 180.3, 270, 280.1, 280.2, 280.3, which can be switched to different positions. One switch position acts as a closed position and disconnects the fluidic connection between the liquid reservoir 12 and the nozzles 18.1, 18.2, 18.3 and between the gas reservoir 28 and said nozzles. A further switch position is used to deliver the cleaning liquid 14 by a fluidic connection being established between the liquid reservoir 12 and the nozzle 18. A further switch position is used to deliver the cleaning gas 30. A final switch position is used to deliver a mixture of cleaning liquid 14 and cleaning gas 30.

[0048] The switch unit 20 of FIG. 1 comprises, for each nozzle 18.1, 18.2, 18.3, a 2/2-way valve 80.1A, 80.2A, 80.3A for the cleaning liquid 14 and a 2/2-way valve 80.1B, 80.2B, 80.3B for the cleaning gas 30. An inlet 82A for the liquid line 24 and an outlet 84A for the nozzle line 26 are provided at each of the 2/2-way valves 80.1A, 80.2A, 80.3A. An inlet 82B for the gas line 32 and an outlet 84B for nozzle line 26 are provided at the 2/2-way valves 80.1B, 80.2B, 80.3B. Each of the nozzle lines 26.1A, 26.1B; 26.2A, 26.2B; 26.3A, 26.3B of the cleaning liquid 14 and of the cleaning gas 28 join together at a junction 86 and there lead to the respective nozzles 18.1, 18.2, 18.3.

[0049] The two 2/2-way valves 80.1A, 80.1B are shown in a position such that the sensor 16.1 is sprayed only with cleaning liquid 14. For this purpose, the 2/2-way valve 80.1A is in the open position and the 2/2-way valve 80.1B is in the closed position. In this case, a fluidic connection is established between the liquid reservoir 12 and the nozzle 18.1, whereas there is no fluidic connection between the gas reservoir 28 and the nozzle 18.1 via the nozzle line 26.1B.

[0050] The two 2/2-way valves 80.2A, 80.2B are shown in a position such that the sensor 16.2 is sprayed only with cleaning gas 30. For this purpose, the 2/2-way valve 80.2A is in the closed position and the 2/2-way valve 80.2B is in the open position. In this case, a fluidic connection is established between the gas reservoir 28 and the nozzle 18.1, whereas there is no fluidic connection between the liquid reservoir 12 and the nozzle 18.1 via the nozzle line 26.1A.

[0051] The two 2/2-way valves 80.3A, 80.3B are shown in a position such that the sensor 16.3 is sprayed with cleaning liquid 14 and cleaning gas 30. For this purpose, the 2/2-way valves 80.3A, 80.3B are in the open position. In this case, a fluidic connection is established between the liquid reservoir 12 and the nozzle 18.3 and between the gas reservoir 28 and said nozzle via the nozzle lines 26.3A, 26.3B.

[0052] The switch unit 120 according to FIG. 3a comprises, for each nozzle 18.1, 18.2, 18.3, a 3/2-way valve 180.1, 180.2, 180.3 which can be switched to three positions. An inlet 182A for the liquid line 24 and an inlet 182B for the gas line 32 and an outlet 184 for the nozzle line 26 are provided at each of the 3/2-way valves 180.1, 180.2, 180.3. A sensor cleaning system 10 comprising the switch unit 120 allows the respective sensors 16.1, 16.2, 16.3 to be cleaned by means of the cleaning liquid 14 or the cleaning gas 30.

[0053] The switch unit 220 according to FIG. 3b comprises an upstream 2/2-way valve 270 comprising an inlet 272A for the liquid line 24 and an inlet 272B for the gas line 32 and an outlet 274 to the junction 276, which establishes the fluidic connection to the downstream 2/2-way valves 280.1, 280.2, 280.3. The 2/2-way valves 280.1, 280.2, 280.3 each comprise an inlet 282 for connecting the line coming from the junction 276 and an outlet 284 for the nozzle lines 26.1, 26.2, 26.3. A sensor cleaning system 10 comprising the switch unit 220 allows the sensors 16.1, 16.2, 16.3 to be cleaned by means of the cleaning liquid 14 or the cleaning gas 30.

[0054] According to the invention, further switch units (not shown) having any arrangement of switch valves are conceivable. It is crucial that the liquid line 24 and the gas line 32 each lead into the switch valves, or the switch valves can be switched to positions by the control unit 22, such that the sensors 16.1, 16.2, 16.3 can be cleaned via the nozzle line 26 by means of the cleaning liquid 14 leaving the at least one nozzle 18 and/or the cleaning gas 30 leaving the at least one nozzle 18.

[0055] The control unit 22 is in particular designed such that the sensors 16.1, 16.2, 16.3 are cleaned at defined time intervals depending on the time of year, the weather and the vehicle location and/or based on a cleaning signal from the sensors 16.1, 16.2, 16.3 to be cleaned and/or a dirt sensor 70 on the sensors 16.1, 16.2, 16.3. It is also advantageous if the sensors 16.1, 16.2, 16.3 to be cleaned determine their own contamination condition. Of course, it is also conceivable for dirt sensors to be provided, by means of which the particular degree of contamination of the sensors 16.1, 16.2, 16.3 to be cleaned can be determined. Depending on the degree of contamination detected, the sensors 16.1, 16.2, 16.3 can then be cleaned in an automated manner by means of the sensor cleaning system 10.