Method for controlling a pump for cleaning sensors in a vehicle - Patents.com

Abstract

The invention relates to a control method (1) for controlling a washing pump (20) for washing a sensor (31) of a vehicle (3), said control method (1) comprising the steps of: receiving (E1) at least one washing request (Rq) from at least one sensor (31) of said vehicle (3); determining (E2) a flow rate (D) of a washing fluid (F) as a function of said at least one washing request (Rq); and adapting (E3) the supply voltage (U1) of said washing pump (20) as a function of said flow rate (D) of washing fluid (F) by means of a pulse width modulation (PWM) signal, thereby providing a predetermined pressure (P1) for said flow rate (D) of washing fluid (F) and sending said washing fluid (F) at said predetermined pressure (P1) to a spray nozzle (22) associated to said at least one sensor (31).

Description

[Technical field]

[0001] The present invention relates to a method for controlling a pump for cleaning sensors in a vehicle. The present invention is particularly applicable to motor vehicles, but is not limited thereto. [Background technology]

[0002] In the field of automobiles, and in particular in the field of autonomous or semi-autonomous automobiles, there are multiple sensors, such as lidar, radar or cameras. In order to make autonomous or semi-autonomous driving as efficient and reliable as possible, the information provided by the sensors must be of the highest possible quality. It is therefore essential to keep the outer surfaces of these sensors clean. For this reason, it is necessary that said outer surfaces can be cleaned frequently when they become soiled. For this purpose, a method exists for controlling a pump for cleaning the sensors of a vehicle. This method is known to the person skilled in the art and controls a low-pressure cleaning pump intended to clean the windshield at a low pressure in the range of 2-3 bar. This control method controls multiple low-pressure pumps in series to obtain a high pressure of 6-8 bar so that multiple sensors, 10 or more, can be cleaned simultaneously.

[0003] A drawback of this prior art is that, due to the multiple sensors, the low pressure pumps are used much more frequently than for windshield cleaning, which causes them to wear out faster, and they are at high risk of damage because they are not inherently configured to operate in series or to receive as input pressurized wash fluid originating from another pump located upstream. Summary of the Invention

[0004] In this context, the object of the invention is to propose a method for controlling a pump for cleaning sensors for vehicles, which is able to address the above-mentioned drawbacks.

[0005] To this end, the invention relates to a control method for controlling a washing pump for washing sensors of a vehicle, said control method comprising the steps of: receiving at least one cleaning request from at least one sensor of said vehicle; - determining a flow rate of a cleaning fluid as a function of said at least one cleaning request; - adapting the supply voltage of said washing pump as a function of said flow rate of washing fluid by means of a pulse width modulated signal to provide a predetermined pressure for said flow rate of washing fluid and to deliver said washing fluid at said predetermined pressure to a spray nozzle associated with said at least one sensor; A control method is proposed that includes the following:

[0006] Therefore, with this control method, it is no longer necessary to use a low pressure cleaning pump, which is not suitable for cleaning multiple sensors at the same time, and a high pressure cleaning pump is used for this purpose.

[0007] In one non-limiting embodiment, the control method may further comprise one or more additional features from the following, taken alone or in any technically possible combination:

[0008] In one non-limiting embodiment, the step of adapting the supply pressure is based on a chart of different pressures at different flow rates.

[0009] In one non-limiting embodiment, when the pulse width modulated signal has a 100% duty cycle, the supply voltage of the wash pump matches the voltage of the vehicle's battery.

[0010] In one non-limiting embodiment, the step of adapting the supply voltage is also performed as a function of at least one environmental condition, which in one non-limiting embodiment is the outside air temperature.

[0011] In one non-limiting embodiment, the at least one sensor is a lidar, a radar, or a camera.

[0012] In one non-limiting embodiment, the predetermined pressure is determined as a function of at least one static parameter.

[0013] In one non-limiting embodiment, the at least one static parameter is the distance between the spray nozzle and its associated sensor, the cleaning quality, the nature of the sensor, and the total number of sensors.

[0014] In one non-limiting embodiment, the predetermined pressure ranges from 6 bar to 8 bar.

[0015] Also proposed is a computer program product comprising instructions which, when executed by a computer, cause said computer to carry out said steps of said control method.

[0016] Also proposed is a non-transitory (non-transient) computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the control method.

[0017] There is also provided a cleaning system for cleaning a sensor of a vehicle, comprising: at least one flushing pump; a plurality of spray nozzles; a drive control unit, A cleaning system comprising: The drive control unit includes: receiving at least one cleaning request from at least one sensor of said vehicle; - determining a flow rate of a cleaning fluid as a function of said at least one request, - adapting the supply voltage of the cleaning pump as a function of the flow rate of cleaning fluid by a pulse width modulated signal to provide a predetermined pressure for the flow rate of cleaning fluid and delivering the cleaning fluid at the predetermined pressure to a spray nozzle associated with the at least one sensor; A cleaning system is proposed that is configured as follows.

[0018] In one non-limiting embodiment, the drive control unit is further configured to control the opening of a solenoid valve associated with the spray nozzle to allow the cleaning fluid to pass through a pipe connecting to the spray nozzle.

[0019] The invention and its various applications will be better understood upon reading the following description and upon referring to the accompanying drawings, in which: [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a flow chart of a method for controlling a pump for cleaning a sensor of a vehicle according to one non-limiting embodiment of the present invention. [Diagram 2] FIG. 2 shows a non-limiting example of a first chart used by the control method of FIG. 1 to adapt the supply voltage of a wash pump, according to one non-limiting embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic diagram of a system for cleaning sensors in a vehicle, according to one non-limiting embodiment of the present invention. [Figure 4] FIG. 4 shows a non-limiting example of a second chart illustrating the current draw of a wash pump controlled by the control method of FIG. 1 according to one non-limiting embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Structurally or functionally identical elements illustrated in various figures will be labeled with the same reference numbers unless otherwise noted.

[0022] A control method 1 for controlling a washing pump 2 for washing a sensor 31 of a vehicle 3 according to the present invention is shown in Fig. 1. In a non-limiting embodiment, the vehicle 3 is an automobile. An automobile is understood to mean any type of electric vehicle. This embodiment is taken as a non-limiting example in the following description. Therefore, in the following description, the vehicle 3 is also referred to as an automobile 3. In a non-limiting embodiment, the automobile 3 is an autonomous vehicle or a semi-autonomous vehicle.

[0023] As shown in FIG. 3, the vehicle 3 comprises a battery 30 and at least one sensor 31. In a non-limiting example, the battery 30 provides a voltage U0 of 15V (volts). In a non-limiting embodiment, the sensor 31 is a lidar, a radar or a camera. The sensor 31 comprises an outer surface to be cleaned. In the case of a radar, the radar waves transmitted by the radar and the return radar waves received by the radar traverse this outer surface. In the case of a lidar, the laser beam transmitted by the lidar and the return waves received by the lidar traverse this outer surface. In the case of a camera, this outer surface represents the outer surface of the camera optics. The sensor 31 has a visibility threshold, which, if exceeded by the surface becoming too dirty, the sensor 31 cannot operate normally. When this visibility threshold is reached, the sensor 31 is configured to feed back information indicating that the visibility threshold has been reached by a cleaning request Rq.

[0024] In a non-limiting embodiment, the car 3 is equipped with a number of sensors 31. This non-limiting embodiment is taken as a non-limiting example in the following description. In a non-limiting embodiment, it is equipped with approximately ten sensors 31. In FIG. 3, only five sensors 31 are shown; three at the front and two at the rear. It should be noted that the sensors 31 can of course also be arranged on the sides of the car 3. The sensors 31 are configured to provide information about the external environment of the car 3. This information is utilized to implement functions, in particular for autonomous or semi-autonomous driving. In a non-limiting example, this information is an image of the external environment, the presence of stationary or moving objects in front, behind or on the sides of the car 3.

[0025] Depending on the level of vehicle autonomy, non-limiting examples include the following capabilities: - Emergency Brake Assist, - Automatic parking by steering, - Adaptive cruise control without driver intervention, - vehicle steering (longitudinal and lateral trajectory control, keeping the vehicle in its lane and adapting its speed to the traffic flow); - Vehicle movement management on highways and roads with visible road signs; - Vehicle control without driver intervention.

[0026] As shown in Fig. 3, the automobile 3 is equipped with a washing system 2. In a non-limiting embodiment, the washing system 2 includes: at least one washing pump 20 for washing the sensor 31, the washing pump 20 being configured to direct a washing fluid F through a pipe 23 to the spray nozzle 22; at least one storage tank 21 configured to store a cleaning fluid F; a number of spray nozzles 22 configured to deliver a cleaning fluid F to the outer surface of the sensor 31; a number of pipes 23 arranged to convey the cleaning fluid F from said at least one storage tank 21 to the spray nozzles 22; a distribution module 24 comprising a number of solenoid valves 240 arranged to distribute the cleaning fluid F to the sensors 31; - a drive control unit 25 configured to drive said at least one washing pump 20 and said plurality of solenoid valves 240; It is equipped with:

[0027] In a non-limiting example, the washing fluid F is a freeze-resistant windshield cleaning fluid. The washing pump 20, the tank 21, the plurality of pipes 23 and the distribution module 24 form a distribution circuit 26 for the washing fluid F. In a non-limiting embodiment, the vehicle 3 comprises two distribution circuits 26, one located at the front and one at the rear of the vehicle 3. This allows for example simultaneous cleaning of a plurality of sensors 31 located at the front and at the rear of the vehicle 3. Thus, in this non-limiting embodiment, the vehicle 3 comprises two storage tanks 21, one located at the front and one at the rear, and two washing pumps 2, one located at the front and one at the rear. Each washing pump 20 is directly arranged at the output of one of the storage tanks 21. In FIG. 3, only one distribution circuit 26 is shown. If the vehicle 3 comprises two distribution circuits 26, in this example the drive control unit 25 is configured to control the two washing pumps 20 and the plurality of solenoid valves 240 of the two distribution circuits 26.

[0028] The spray nozzle 22 is associated with a sensor 31. Thus, there are as many spray nozzles 22 as there are sensors 31. The spray nozzle 31 is placed in the vicinity of the sensor 31 with which it is associated. The distance d from the sensor 31 depends on the outer surface of the sensor 31 to be cleaned. The smaller the outer surface of the sensor 31, the closer the spray nozzle 22 is placed to the sensor 31. In a non-limiting embodiment, the distance d is in the range of 1 cm (centimeter) to 10 cm. In a non-limiting example, for a sensor 31 having a diameter of 15 mm (millimeter), such as a wide-angle camera, the distance d is 1 cm. In a non-limiting example, for a sensor 31 having a diameter of 20 cm to 5 cm, such as a lidar, the distance d is 5 cm. In a non-limiting example, the spray nozzle 22 has an activation time in the range of 50 ms (milliseconds) to a maximum of 500 ms. This activation time is the opening time for passing the cleaning fluid F. Thus, it represents the time for spraying the cleaning fluid F to the sensor 31. It should be noted that this time is relatively short so as not to disturb the operation of the sensor 31 too long. Indeed, during cleaning the camera 31 cannot capture images for example. Also, the activation time is relatively short so as to ensure a reasonable consumption of the cleaning fluid F.

[0029] It should be noted that the spray nozzles 22 are associated with solenoid valves 240. Thus, the distribution module 24 includes as many solenoid valves 240 as there are spray nozzles 22. Thereby, the supply of cleaning fluid F by any spray nozzle 22 is managed by controlling only one solenoid valve 240. The solenoid valves 240 are controlled by the drive control unit 25.

[0030] The cleaning pump 20 is a high-pressure cleaning pump. In a non-limiting embodiment, the cleaning pump 20 can provide a pressure P1 in the range of 6 to 8 bar for a flow rate D of the cleaning fluid F. In a non-limiting embodiment, the cleaning pump 20 is an electronic pump managed by an electric motor. In a non-limiting embodiment, the electric motor is a brushless motor. This ensures the reliability of the cleaning pump 20 compared to cleaning pumps with electric motors with brushes. The cleaning pump 20 is powered by a supply voltage U1. The supply voltage U1 of the cleaning pump 20 can be changed based on a pulse width modulation (PWM) signal. This allows the rotation speed of the electric motor to be changed. By changing the rotation speed, the pressure of the cleaning fluid F output from the cleaning pump 20 is changed. In particular, an increase in the rotation speed increases the pressure of the cleaning fluid F. The pressure of the cleaning fluid F output from the cleaning pump 20 can therefore be adapted so that the pump provides a predetermined pressure P1 for sending the cleaning fluid F to the spray nozzle 22 at a given flow rate D.

[0031] It should be noted that the pressure P1 is determined by the car manufacturer or the designer of the washing system 2 as a function of the design structure of the washing system. The pressure P1 is therefore predetermined, since it is determined upstream, i.e. before the use of the washing pump 20. The pressure P1 is determined independently of the number of sensors 31 to be washed. It is therefore independent of the number of sensors 31 to be washed. In a non-limiting example adopted in the following description, the pressure P1 is 6 bar. In a non-limiting embodiment, the pressure P1 is determined as a function of at least one static parameter p1, i.e. a parameter that, contrary to a dynamic parameter, does not change as the vehicle 3 travels or as the operation for washing the sensors 31 progresses. In a non-limiting example, the at least one static parameter p1 is the distance d between the spray nozzle 22 and the sensor 31 to which it is associated, the desired cleaning quality, the nature of the sensor 31, or the total number of sensors 31. The pressure P1 can therefore be determined as a function of one or more static parameters p1.

[0032] The wash pump 20 is controlled by a control method 1, which is described in one non-limiting embodiment below with reference to Fig. 1. The control is performed by a drive control unit 25 of the wash system 2. In one non-limiting embodiment, the control is performed via a data bus 28 connecting the drive control unit 25 to the wash pump 20. In one non-limiting example, the data bus 28 is a Local Interconnect Network (LIN) data bus.

[0033] As shown in FIG. 1, the control method 1 includes the following steps.

[0034] In step E1, indicated as F1(25, 31, Rq), the drive control unit 25 receives at least one cleaning request Rq from at least one sensor 31 of the vehicle 3. In fact, the sensor 31 is configured to transmit such a cleaning request Rq when it becomes soiled, i.e. when its external surface becomes soiled. In a non-limiting embodiment, the drive control unit 25 receives a number of cleaning requests Rq from N sensors 31, where N=1 to m, m being an integer. In a non-limiting example adopted in the following description, five sensors 31 are to be washed simultaneously. Thus, the electronic control unit 25 receives five cleaning requests Rq from each of the five sensors 31 to be washed.

[0035] In step E2, denoted as F2(25, D(F)), the drive control unit 25 determines the flow rate D of the cleaning fluid F as a function of said at least one cleaning request Rq. The flow rate D is thus determined as a function of the number N of the received cleaning requests Rq and thus as a function of the total number of sensors 31 to be simultaneously cleaned. In this way, the total flow rate is determined. Thus, in a non-limiting example of five sensors 31, the electronic control unit 25 determines the flow rate D of the cleaning fluid F as a function of the five received cleaning requests Rq. In one non-limiting example, the flow rate D required for a single sensor 31 is 8 mL / s (milliliters per second). This flow rate D per sensor 31 is determined during the design of the cleaning system 2. The flow rate F is determined to obtain a good cleaning efficiency versus a rate of consumption of the cleaning fluid F. Thus, in a non-limiting example of five sensors 31, to simultaneously clean five sensors 31, the total flow rate D is 40 mL / s. In another non-limiting example, to flush two sensors 31 simultaneously, the total flow rate D is 16 mL / s.

[0036] In step E3, shown as F3(25, U1, PWM, D, T, P1(p1)), the drive control unit 25 adapts the supply voltage U1 of the cleaning pump 20 as a function of the flow rate D of the cleaning fluid F by a pulse width modulation (PWM) signal to provide a predetermined pressure P1 to obtain the flow rate D of the cleaning fluid F and sends the cleaning fluid F at the pressure P1 to the spray nozzle 22 associated with the at least one sensor 31. Thus, in a non-limiting example of five sensors 31, the cleaning fluid F is sent to the spray nozzle 22 with a pressure P1 of 6 bar and a total flow rate D of 40 mL, and the five sensors 31 are washed simultaneously.

[0037] A pulse width modulated (PWM) signal (having a duty cycle greater than 0) is applied to the wash pump 20, causing the pump to start, and the pump delivers wash fluid F at the pressure P1 to each spray nozzle 22 associated with the sensor 31 to be cleaned.

[0038] In a non-limiting embodiment, the supply pressure U1 is adapted based on various charts Ab1 for each flow rate. FIG. 2 shows a non-limiting example of such a chart Ab1. The pressure P is shown on the left vertical axis in bar and the flow rate D is shown on the horizontal axis in milliliters per second (ml / s). The chart Ab1 has a number of straight lines Ci (i=0 to n, n being an integer). This makes it possible to determine the supply voltage U1 to be applied to the washing pump 20 as a function of the desired pressure P1 for any flow rate of the washing fluid F for all sensors 31 to be washed simultaneously. In the non-limiting example shown in FIG. 2, the chart Ab1 provides eleven pressure / flow curves C1 to C11 for each supply voltage U1 over the range of 6V to 16V in 1V increments. This gives the following pairs: C1 / 6V, C2 / 7V, C3 / 8V, C4 / 9V, C5 / 10V, C6 / 11V; C7 / 12V, C8 / 13V, C9 / 14V, C10 / 15V, C11 / 16V. Depending on the flow rate D, chart Ab1 also shows the number N of sensors 31 that are washed at the same time. It can therefore be seen that for D=40 ml / s there are 5×N sensors 31. It can therefore be seen that for D=16 ml / s there are 2×N sensors 31.

[0039] In a non-limiting example of five sensors 31 to be cleaned simultaneously, it can be seen from the chart Ab1 that for an operating point pt1 of 40 mL / s at 6 bar, it is close to the curve C7. The curve C7 corresponds to a supply voltage U1 of 15 V (volts), which is therefore applied to control the cleaning pump 20. The curve C7 closest to the operating point pt1 is therefore taken to determine the supply pressure U1 to be applied. To this end, the drive control unit 25 configures the supply voltage U1 of the cleaning pump 20 to 15 V, to obtain a pressure of 6 bar for a flow rate D of 40 mL / s. In another non-limiting example, for an operating point pt2 of 40 mL / s at 4 bar (for five sensors 31), the supply voltage U1 is 10 V. This corresponds to the curve C5 on the chart Ab1 closest to the operating point pt2. In another non-limiting example, for an operating point pt3 ​​of 16 mL / s at 6 bar (for two sensors 31), the supply voltage U1 is 9 V. This corresponds to the curve C4 on the chart Ab1 that is closest to the operating point pt3.

[0040] It can thus be seen that depending on the number N of sensors 31 to be cleaned simultaneously and depending on the desired pressure P1, the cleaning pump 20 does not always operate at full power, thus avoiding premature emptying of the associated storage tank 21.

[0041] It should be noted that the supply voltage U1 of said washing pump 20 corresponds to the voltage U2 of the battery 30 of the vehicle 3, i.e. 15 V in the non-limiting example provided, when the pulse width modulation (PWM) signal has a duty cycle of 100%. When the pulse width modulation (PWM) has a duty cycle of 50%, the supply voltage U1 is equal to 7.5 V in the non-limiting example provided. It should be noted that the current consumption I of the washing pump 20 can be reduced by adapting the supply voltage U1 as a function of the desired pressure P1 and the determined flow rate D. In the graph Ab2 shown in FIG. 4, the vertical axis on the right side indicates the current consumption I in amperes (A) and the horizontal axis indicates the flow rate D in milliliters per second (ml / s). The chart Ab2 has a number of straight lines C'i (i=~k, k being an integer). This makes it possible to determine the current consumption I as a function of the determined flow rate D of the washing fluid F for all sensors 31 to be washed simultaneously. In a non-limiting example shown in FIG. 4, chart Ab2 provides eleven flow / intensity curves C'1 to C'11 for each supply voltage U1 ranging from 6V to 16V in 1V increments. This results in the following pairs: C'1 / 6V; C'2 / 7V, C'3 / 8V, C'4 / 9V, C'5 / 10V, C'6 / 11V; C'7 / 12V, C'8 / 13V, C'9 / 14V, C'10 / 15V, C'11 / 16V. Operating points pt1, pt2, and pt3 are also shown in FIG. 4. Thus, as shown in chart Ab2, for five sensors 31 and operating point pt1, the current consumption I is approximately 14A (amperes). In another non-limiting example, for five sensors 31 and operating point pt2, the current consumption I is close to 9A. In another non-limiting example, for two sensors 31 and operating point pt3, the current draw I is approximately 14 A. It can therefore be seen that the current draw I of the wash pump 20 varies as a function of the number N of sensors 31 being simultaneously cleaned and the desired pressure P1. For this reason, the wash pump 20 does not always draw the maximum current I.

[0042] It should be noted that the flow rate D is expressed in ml / s and is rounded down to the nearest whole number, as shown in Figures 2 and 4. It should be noted that the flow rate D is expressed in ml / s and is rounded down to the nearest whole number, as shown in Figures 2 and 4. However, it may also be expressed in L / min. In this case, the following matches are possible: 8.3 ml / s = 0.5 L / min; 16.6 ml / s = 1 L / min; 25 ml / s = 1.5 L / min; 33.3 ml / s = 2 L / min; 42.6 ml / s = 2.5 L / min; 50 ml / s = 3 L / min; 58.3 ml / s = 3.5 L / min; 66.6 ml / s = 4 L / min; 75 ml / s = 4.5 L / min; 83.3 ml / s = 5 L / min; 91.6 ml / s = 5.5 L / min; 100 ml / s = 6 L / min.

[0043] It should be noted that environmental conditions can affect the flow of the cleaning fluid F. In particular, the outside air temperature T (also called temperature T) affects the cleaning fluid F. Indeed, the lower the temperature T, the more viscous the cleaning fluid F is and the less it flows through the pipe 23. Its flow rate D decreases. For example, at -10 degrees Celsius, the flow is half that at room temperature. To overcome the viscosity of the cleaning fluid F, the duty cycle of the pulse width modulation (PWM) signal must be increased. Therefore, in a non-limiting embodiment, the supply voltage U1 is also adapted as a function of the temperature T. For this purpose, a multiplication correction factor is applied to the duty cycle of the pulse width modulation (PWM) signal after application of the chart Ab1. In a non-limiting embodiment, the multiplication correction factor is determined from a curve (not shown) that provides the value of the multiplication correction factor as a function of the temperature T.

[0044] Thus, the control method 1 allows voltage control of the washing pump 20 by a pulse width modulated (PWM) signal as a function of the sensor demand, i.e. as a function of the number N of sensors 31 to be washed simultaneously and the desired pressure P1. In this way, the outer surfaces of the sensors 31 are properly cleaned, and therefore, inter alia, the functioning of the autonomous or semi-autonomous vehicle 3 is properly performed. There is no risk of the autonomous or semi-autonomous vehicle 3 ceasing to operate due to the outer surfaces of the sensors 31 becoming dirty.

[0045] Thus, the control method 1 is implemented by a drive control unit 25. As shown in FIG. - receiving at least one cleaning request Rq from at least one sensor 31 of said vehicle 3 (function f1(25, 31, Rq)), - determining a flow rate D of a cleaning fluid F as a function of said at least one request Rq (function f2(25,D(F))), - configured to provide a predetermined pressure P1 for the flow rate D of cleaning fluid F by adapting the supply voltage U1 of the cleaning pump 20 by a pulse width modulation (PWM) signal as a function of the flow rate D of cleaning fluid F and to send the cleaning fluid F at said pressure P1 to a spray nozzle 22 associated with the at least one sensor 31 (function f3(25, U1, PWM, D, T, P1(p1))).

[0046] It should be noted that in one non-limiting embodiment, the drive control unit 25 is further configured to control the opening of the solenoid valve 240 associated with the spray nozzle 22 so that the cleaning fluid F can pass through the pipe 23 connecting to the associated spray nozzle 22 (function f4(25, 240, F)).

[0047] It should be noted that the cleaning system 2 may include one or more computer program products Pg having one or more instruction sequences that can be executed by the drive control unit 25, and the above-mentioned control method 1 can be implemented by executing the instruction sequences.

[0048] This type of computer program Pg may be entered into a non-volatile writable memory of the ROM type, or into a non-volatile rewritable memory of the EEPROM or FLASH type. Said computer program Pg may be entered into the memory at the factory, loaded into the memory or loaded into the memory remotely. The instruction sequences may be machine instruction sequences or sequences of a control language that are interpreted by the processing unit when executed. In the non-limiting example of FIG. 3, the computer program Pg is written into the memory 27 of the cleaning system 2.

[0049] Thus, the washing system 2 comprises at least one memory 27 coupled to said drive control unit 25 via a communication bus 29. The memory 27 is a non-transitory computer-readable storage medium containing instructions that, when executed by a computer, cause the computer to perform said control method 1.

[0050] Naturally, the description of the invention is not limited to the above-mentioned embodiment and the above-mentioned field. Thus, in one non-limiting embodiment, the supply voltage U1 can be adapted as a function of other environmental conditions as well, such as, in a non-limiting example, the atmospheric pressure or the momentary mechanical conditions.

[0051] The invention described above therefore has the following particular advantages: - Ensures long term reliability of the wash pump 20 and provides better wash efficiency compared to using a series of wash pumps. The current consumption I of the washing pump 20 is limited. - The consumption of the cleaning fluid F is limited and the premature emptying of the storage tank 21 associated with the cleaning pump 20 is prevented. The sensor 31 is quickly cleaned. - It is a cheap solution. - more efficient than the solution of coupling the cleaning pump to a pressure sensor, which feeds back the pressure measured in the pipe to the drive control unit via a feedback loop. Indeed, in this example, the cleaning pump starts to operate at full power (maximum supply voltage) and the spray nozzle starts to clean the associated sensor. The pressure sensor can only measure the actual pressure when the cleaning fluid is flowing in the pipe. However, the time to spray the cleaning fluid F is very short (50 ms to 1 s), so that by the time that the pressure builds up in the pipe, the cleaning is already completed, which is a combination of the time for the information from the pressure sensor to return to the drive control unit, the time to calculate the appropriate supply pressure to be applied as a function of the measured pressure, and the time to send the supply voltage information to the cleaning pump.

Claims

1. A control method (1) for controlling a wash pump (20) for washing a plurality of sensors (31) of a vehicle (3), the control method (1) comprising: - a step (E1) of receiving a number of cleaning requests (Rq) from said number of sensors (31) of said vehicle (3), - a step (E2) of determining a flow rate (D) of a cleaning fluid (F) as a function of the number of said plurality of cleaning requests (Rq); - adapting the supply voltage (U1) of the cleaning pump (20) as a function of the flow rate (D) of the cleaning fluid (F) by a pulse width modulation (PWM) signal, thereby providing a predetermined pressure (P1) for said flow rate (D) of the cleaning fluid (F) and sending the cleaning fluid (F) at said predetermined pressure (P1) to a spray nozzle (22) associated with said plurality of sensors (31).

2. 2. Control method (1) according to claim 1, wherein the step of adapting the supply voltage (U1) is performed on the basis of a chart (Ab1) of different pressures per flow rate.

3. 2. The control method (1) of claim 1, wherein the supply voltage (U1) of the washing pump (20) corresponds to a voltage (U2) of a battery (30) of a vehicle (3) when the pulse width modulation (PWM) signal has a duty cycle of 100%.

4. 2. The control method (1) according to claim 1, wherein the adaptation of the supply voltage (U1) is also performed as a function of at least one environmental condition (T).

5. The control method (1) according to claim 1, wherein the plurality of sensors (31) are a lidar, a radar, or a camera.

6. 2. The control method (1) according to claim 1, wherein said predetermined pressure (P1) is determined as a function of at least one static parameter (p1).

7. 7. The control method (1) according to claim 6, wherein the at least one static parameter (p1) is the distance (d) between the spray nozzle (22) and its associated sensor (31), the cleaning quality, the nature of the sensor (31), or the total number of sensors (31).

8. The control method (1) according to claim 1, wherein said predetermined pressure (P1) ranges from 6 bar to 8 bar.

9. A computer program product (Pg) comprising instructions which, when executed by a computer, cause said computer to carry out said steps of the control method according to any one of claims 1 to 8.

10. A non-transitory computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the control method of any one of claims 1 to 8.

11. A washing system (2) for washing a plurality of sensors (31) of a vehicle (3), comprising: at least one washing pump (20), a plurality of spray nozzles (22), a drive control unit (25), In a cleaning system (2) comprising: The drive control unit (25) - receiving a plurality of washing requests from the plurality of sensors (31) of the vehicle (3); - determining a flow rate (D) of a cleaning fluid (F) as a function of the number of said plurality of cleaning requests (Rq); - adapting the supply voltage (U1) of said washing pump (20) as a function of said flow rate (D) of the washing fluid (F) by means of a pulse width modulation (PWM) signal, thereby providing a predetermined pressure (P1) for said flow rate (D) of the washing fluid (F) and sending said washing fluid (F) at said predetermined pressure (P1) to a spray nozzle (22) associated with said plurality of sensors (31); It is configured as follows: A cleaning system (2).

12. The washing system (2) for washing the multiple sensors of a vehicle (3) as described in claim 11, wherein the drive control unit (25) is further configured to control the opening of a solenoid valve (240) associated with the spray nozzle (22) so that the washing fluid (F) can pass through a pipe (23) connecting to the spray nozzle (22).

Images