Fluid distribution system and method, and cleaning system and method, and vehicle incorporating same

Abstract

The present invention relates to a fluid distribution system (40), a cleaning system, and to a vehicle in which the fluid distribution system (40) or cleaning system may be employed. In an embodiment, the vehicle comprises optical sensors serving as advanced driver assistance systems, which is also equipped with the (sensor) cleaning system having a fluid volume (10), two or more electrically actuated fluid pressure sources (20), the fluid distribution system (40), hoses and nozzles allowing to clean the optical devices and to ensure system availability under adverse driving conditions. The fluid distribution system is suitably composed of pressure-actuated flow control devices, actuated in binary mode by hydraulic or pneumatic pressure from the fluid pressure sources and controlled by the logic combination of (the ON / OFF state of the) fluid pressure sources, to achieve the distribution function. This results in as many individually controllable outlets as there are ON / OFF combinations of the fluid pressure sources. This allows to increase the number of individually switchable outlets without increasing the number of individual pressure sources like pumps or electromechanical valves, and avoids the need for complex electronic control.

Description

Fluid Distribution System and Method, and Cleaning System and Method, and Vehicle Incorporating SameTechnical field

[0001] The present invention generally relates to fluid flow management, and more particularly to a fluid distribution system and method, a cleaning system and method, and to vehicle incorporating same. Even more particularly, applications of the invention include automotive on-board fluid distribution systems used to clean exterior optical surfaces.Background of the Invention

[0002] Vehicles such as passenger transport or cargo vehicles are equipped more and more with driver assistance systems such as cameras and optical ranging devices like LIDARs, with the potential to operate in a completely autonomous or driverless mode and relying fully on such sensing devices to assure safe operation. This requires cleaning systems for the sensing devices - to maintain and assure system availability in all environmental conditions.

[0003] Washer systems, composed of a liquid reservoir, electric pumps, hoses and nozzles have been used for a long time to clean windscreens, headlamps, cameras and other devices. These are usually actuated on driver demand and operate in a binary ON / OFF mode, with each pump delivering to one or several outlets in parallel (Fig. 1 , Prior Art), without additional active distribution systems or controls. In the known configuration of Fig. 1 , a washer system comprises one reservoir 10, three pumps 20 and three outlets 60, labelled A, B and C. Lines labelled 44 indicate flow lines I flow conduits ultimately delivering liquid to the outlets. It will be noted that, while Fig. 1 shows an exemplary system with three pumps and three outlets, systems with a different number of pumps / outlets are possible. This technology is in principle adequate for the cleaning of advanced optical sensing devices in future applications with higher levels of automation; however, the number of cleaning surfaces increases with the complexity of driver assistance systems and actuation is automated based on system demand. The latter leads to larger reservoirs, more pumps, a higher number of cleaning outlets and a higher frequency of cleaning events. With the limited amount of liquid carried on board, targeted on-demand cleaning of each individual sensor becomes essential. Also, in addition to cleaningliquid, pressurized air is often required to remove residual liquid droplets or to clear optical surfaces under rain or spray.

[0004] With this evolution, new sensor cleaning system architectures are needed, delivering a targeted spray precisely to the sensor or surface to be cleaned, without consuming more liquid than needed. With the multiplication of surfaces and sensors to be cleaned individually, and with dual fluid (e.g. liquid + air) systems, fluid distribution needs to be managed in a different way as there are usually more individual outlets than there are pumps or fluid pressure sources available.

[0005] Future sensor cleaning systems are therefore expected to rely on a source of fluid pressure delivering the required flow and pressure, and on a distribution system diverting and distributing the fluid to the individual location to be cleaned.

[0006] According to the current state of art, such distribution systems usually rely on electrically actuated valves fed by the pressure source and opening the desired outlet by means of electromagnetic solenoid valves, or by rotary electric actuators selecting the respective outlet through positioning a perforated barrel or disk against the desired outlet port. Figure 2 (Prior Art) illustrates an example using control by means of electromagnetic solenoid valves. A sensor cleaning system has one central pump 20 and an electromechanical distribution block 30 with multiple outlets, requiring an electronic control unit 32 controlling and driving electromechanical valves within the distribution block.

[0007] In another example, US patent application US 2024 / 0059254 A1 discloses a distribution system with a plurality of nozzle units formed consecutively, a transfer conduit configured to pass through the plurality of nozzle units and having one end fluidly connected to an introduction part fed from a washer pump, a plurality of discharge holes configured to correspond to the number of the nozzle units in the transfer conduit and having different angles based on a center of the transfer conduit, and a controller configured to control a rotation angle of the transfer conduit to allow the discharge holes to correspond to the nozzle units in response to a user's request. The controller is an electrically actuated rotary device (motor) positioning the rotor according to the required outlet.

[0008] Other documents, such as DE102019125970B4, DE102022118856A1 , EP4185496B1 , EP3466744B1 or US20220018461A1 describe systems usingelectromagnetically actuated valves to dispense liquid and / or air at the desired outlets.

[0009] A problem is that these electrically actuated distribution systems require dedicated controls with electric power drivers, wiring and electromechanical actuators to move the valve elements.Object of the invention

[0010] It is therefore desirable to provide a system and a method for fluid flow distribution with the functional characteristics of the aforementioned systems, but without the complexity of electric actuation.General Description of the Invention

[0011] In one aspect, there is provided a fluid distribution system configured to control the flow of cleaning fluid to output ports thereof, the fluid distribution system comprising: a plurality of input ports, each input port being configured to be connected to a respective pressure source for receiving a flow of the cleaning fluid therefrom; a plurality of flow control devices configured to distribute the flow of the cleaning fluid received at one, a subset or all of the input ports; and a plurality of outlet ports, each outlet port being configured to receive cleaning fluid via one, a predetermined subset or all of the plurality of flow control devices; wherein the plurality of flow control devices are configured to direct, at a given time, the flow of the cleaning fluid to an individual outlet to clean an element corresponding to the individual outlet. In accordance with the invention, each flow control device is configured to direct incoming cleaning fluid flow received at an inlet of the flow control device to one of two separate outlets of the flow control device, depending on whether the cleaning fluid is received under pressure at the flow control device from one of the pressure sources or not, such that the individual outlet is dependent upon which one or ones of the plurality of input ports is currently receiving the cleaning fluid under pressure from a respective pressure source.

[0012] Preferably, each flow control device comprises a shiftable element configured to direct incoming cleaning fluid flow received at an inlet of the flow control device to one of two separate outlets of the flow control device, whereby shifting is achieved by a transition from (i) the cleaning fluid not being received atthe flow control device, i.e. at a control inlet (also known as pilot port or pilot conduit) thereof, under pressure from one of the pressure sources to (ii) the cleaning fluid being received under pressure from one of the pressure sources, or vice versa. Preferably, each flow control device comprises (i) a main inlet for receiving a flow of cleaning fluid for direction to one of the outlets of the flow control device and (ii) a control inlet for receiving the cleaning fluid for controlling the shiftable element. In embodiments, the or each flow control device comprises a pilot valve, e.g. having a pilot port (or control inlet) inlet in addition to a main inlet and multiple outlets.

[0013] In an embodiment, for at least one of the inlet ports, the fluid flow arriving from the respective pressure source is routed through a first flow control device and subsequently through at least one additional flow control device.

[0014] Preferably, for at least one of the inlet ports, the inlet port is connected to a series of flow control devices whereby each flow control device in the series is controlled by one of the pressure sources corresponding to that inlet port.

[0015] Preferably, the flow control devices are interconnected via fluid conduits such that the flow of the cleaning fluid is directable to any of the outlets to individually clean a corresponding element.

[0016] Preferably, at a given time, each of the inlet ports is configured for, independently of the other inlet ports, either receiving the cleaning fluid under pressure or not receiving the cleaning fluid, corresponding to the respective pressure source individually being turned ON or OFF, respectively, whereby a plurality of different configurations of the states of the flow control devices is possible, the state being either that of allowing flow or that of blocking flow. Preferably, each of the plurality of different configurations of the states of the flow control devices corresponds to a different individual outlet, and the number of different individual outlets is less than or equal to the number of combinations of the inlet ports either receiving the cleaning fluid under pressure or not receiving the cleaning fluid, corresponding to the respective pressure source individually being turned ON or OFF, respectively.

[0017] In an embodiment, the fluid distribution system further comprises, for each of the inlet ports, a respective non-return valve between a control inlet of the flow control device and a point disposed upstream of the plurality of flow control devicesat which flows arriving from multiple pressure sources merge. It will be noted that by this configuration, the incoming pressure flows serve to individually control the pilot valves, but then they merge internally to the distribution device to form a common supply flow to be supplied to the output ports. As a result, the fluid distribution system does not require separate inlets for control and flow, which makes this embodiment particularly efficient.

[0018] Preferably, the flow control devices are combined and integrated in one enclosure or multiple interconnected enclosures.

[0019] In an embodiment, the fluid comprises a liquid and at least one of the plurality of flow control devices is actuated by hydraulic pressure supplied by one or more of the pressure sources.

[0020] In an embodiment, the fluid comprises a gas and at least one of the plurality of flow control devices is actuated by pneumatic pressure supplied by one or more of the pressure sources.

[0021] In another aspect, there is provided a cleaning system for cleaning each of a plurality of elements, the cleaning system comprising: one or more containers configured to store and supply cleaning fluid; at least two pressure sources configured to deliver cleaning fluid stored in the one or more containers whereby, in use, the cleaning fluid may be delivered under pressure; a control system configured to turn ON or OFF, at a given time, each of the pressure sources independently of the other pressure sources; the distribution system of any of claims 1 to 12 of the appended claims or as described herein, each input port thereof being connected to a respective pressure source; and a plurality of nozzles, each nozzle being configured to receive cleaning fluid from a respective one of the outlet ports of the fluid distribution system and to direct the cleaning fluid onto a respective element; wherein the control system is configured, at a given time, to turn ON one, a subset or all of the pressure sources, with the other pressure sources remaining OFF, whereby the one or ones of the plurality of input ports of the fluid distribution system that are currently receiving the cleaning fluid under pressure correspond to the or those pressure sources that are turned ON.

[0022] Preferably, each pressure source is configured to be turned ON or OFF individually such that multiple combinations of ON and OFF pressure sources maybe defined. Preferably, the number of individual outlet ports is less than or equal to the number of possible ON / OFF combinations of pressure sources.

[0023] In an embodiment, the control system is configured to: receive a command identifying an element, nozzle or outlet port; access a mapping in a storage, the mapping defining an association between (i) each element, nozzle or outlet port and (ii) a predetermined combination of pressure sources; retrieve using the mapping the predetermined combination corresponding to the identified element, nozzle or outlet port; wherein turning ON, at a given time, by the control system, one, a subset or all of the pressure sources, with the other pressure sources remaining OFF, is performed based upon the retrieved predetermined combination. It will be appreciated that in another embodiment, the control system may be based on simple mechanical switches, so that the need for further electronic control is eliminated.

[0024] In an embodiment, in which the fluid is a liquid, the pressure sources comprise controllable liquid pumps each having one or more outlets. In embodiments, the controllable liquid pumps may be electric liquid pumps.

[0025] In another embodiment, in which the fluid is a liquid, the containers comprise hydrostatically or otherwise pressurized containers and / or the pressure sources comprise actuatable valves, e.g. electrically actuated hydraulic valves.

[0026] In an embodiment, in which the fluid is a gas, the containers comprise pressurized containers and / or the pressure sources comprise actuatable valves, e.g. electrically actuated valves, configured to open or close pressure supply to the downstream fluid distribution system.

[0027] It will be noted, that in the context of the present invention, the term “electric liquid pump” or “electrically actuated valve” is to be understood as an example, and refers to any way of translating a command into a pressure delivery, which could also be achieved through mechanical or manual actuation as opposed to electrical.

[0028] In another aspect, there is provided an automotive vehicle, comprising: the cleaning system of any of claims 13 to 16 of the appended claims or as described herein, wherein each of a plurality of elements comprises an optical surface of the vehicle.

[0029] In embodiments, the optical surface comprises a window, a headlamp, or the surface of an optically transmissive member of a camera, a LIDAR device or other optical sensor.

[0030] In another aspect, there is provided a fluid distribution method to control the flow of cleaning fluid, the method comprising: providing the fluid distribution system of any of claims 1 to 12 of the appended claims or as described herein; and causing the plurality of flow control devices to direct, at a given time, the flow of the cleaning fluid to an individual outlet to clean an element corresponding to the individual outlet, wherein the individual outlet is dependent upon which one or ones of the plurality of input ports is currently receiving the cleaning fluid under pressure from a respective pressure source.

[0031] In another aspect, there is provided a cleaning method for cleaning each of a plurality of elements, the cleaning method comprising: providing the cleaning system of any of claims 13 to 19; and causing, using the control system, at a given time, one, a subset or all of the pressure sources to be turned ON, with the other pressure sources remaining OFF, whereby the one or ones of the plurality of input ports (or inlets) of the fluid distribution system that are currently receiving the cleaning fluid under pressure correspond to the or those fluid pressure sources that are turned ON; and whereby a nozzle, among the plurality of nozzles, corresponding to the individual outlet is caused to dispense the cleaning fluid to clean the element corresponding to the individual outlet.

[0032] In one or more embodiments of the invention, the above object is solved by an automotive vehicle comprising optical sensing surfaces, sensors, cameras or LIDAR’s, sometimes also referred to as ADAS (Automated Driver Assistance Systems), as well as a fluid-based cleaning system dispensing fluid to the said optical sensing surfaces to remove dirt or similar visual obstruction. In such a sensor cleaning system, the cleaning fluid is typically washer liquid, but may as well be complemented by a parallel similar system dispensing pressurized air to remove liquid droplets or dust from the surfaces. According to embodiments of the invention, the cleaning fluid is contained in at least one reservoir which is equipped with at least two pressure sources delivering said cleaning fluid to said distribution system. In embodiments, to serve multiple individual outlets, the cleaning fluid is routed through a logical arrangement of pressure-actuated pilot valves downstream of thepressure sources and guiding the cleaning fluid to the desired outlet by means of conduits or hoses routed throughout the vehicle. In embodiments, the pilot valves are individually actuated by the pressure sources they are assigned to. Moreover, a vehicle according to embodiments of the invention further comprises simple electrical controls allowing to activate the pressure sources individually or collectively in as many logic combinations as available, resulting in the cleaning fluid flow to be dispensed to, and only to, the individual outlet corresponding to one specific logic combination.

[0033] In the context of the present invention, the term “fluid” or “cleaning fluid” is to be understood in its broadest possible way, and refers to any media used for cleaning the sensing surfaces. While liquid media is mostly used, the principle also works with systems using gaseous media, typically air, therefore it shall be extended to such media as well.

[0034] In the context of the present invention, the term “reservoir” is to be understood in its broadest possible way and refers to the volume used to store and carry the fluid. This volume could be under ambient pressure, usually in the case of liquid media, or under overpressure, usually in the case of gaseous media.

[0035] In the context of the present invention, the term “pressure source” is to be understood in its broadest possible way, and refers to any device allowing to generate or deliver pressurized fluid to the system, either by generating the pressure, typically an electrical or mechanical pumping device, or by opening a valve to release pressure to the system from a pressurized reservoir. The skilled person will appreciate that it may as well be another device, like an electrically or mechanically actuated valve, re-directing the liquid from a central pump or another source of pressure.

[0036] In the context of the present invention, the term “pilot valve” is to be understood in its broadest possible way, and refers to any device meant to divert a fluid flow as a function of the applied pilot pressure (e.g. at a pilot port or control inlet). In its simplest embodiment, a hydraulic valve is a flap or a body moving between two positions and opening or closing an orifice. In the context of the present invention, the valve motion is generated by hydraulic or pneumatic pressure, not by electromechanical action.

[0037] The inventive principle of the presently described system lies in the use of fluid pressure, already available in any existing cleaning system, to generate the control of flow control devices (e.g. valve motion). This advantageously avoids a drawback of currently-known systems, which use electrical actuators or other sources of energy to create valve motion, so require incremental electrical power systems.

[0038] According to a simple embodiment, the pressure-actuated sensor cleaning system is composed of a cascade-type arrangement of pilot-valves, connected by conduits, fed by two or more pressure sources on the inlet side and feeding a number of outlets exceeding the number of pressure sources. This arrangement may be composed of individual components connected by hoses, or it may be fully integrated in a closed system with integrated valve elements connected by internal galleries or conduits.

[0039] In an embodiment, a cleaning system has three pressure sources and a fluid distribution system able to activate up to seven outlets independently, whereby the seven outlets correspond to the seven possible binary ON / OFF combinations of the pressure sources.

[0040] The skilled person will appreciate that, in accordance with the invention, starting from two as the lowest number of independent pressure sources, an infinity of combinations are theoretically possible by adding or combining additional pressure sources of any kind to further multiply the number of combinations (possible binary ON / OFF combinations of the pressure sources), and thereby the possible number of (individual) outlets.

[0041] An advantage of the invention is that, as all vehicles are already equipped with washer pumps, the extra complexity, mass and space needed for the pressure- actuated distribution system is minimal compared to alternative (known) systems. In addition, as the pressure from the individual pumps is also used to control and operate the distribution system, no additional electrical or mechanical energy is required.

[0042] Beneficially, in accordance with the invention, the only requirement is a logic allowing to switch multiple pressure sources in a synchronous way (i.e. switch one, a subset or all of the sources ON, with the remainder remaining OFF) to achieve thedesired combined pilot valve actuation. This may be achieved through appropriate arrangement of electric hardware like wires and switches, or a simple software logic in case of electronically actuated pressure sources.

[0043] In embodiments, some vehicles may also be equipped with electrically actuated valves downstream of a single liquid pump or downstream of an air pressure source. These valves then take the role of the pressure source, with the downstream pressure-actuated distribution system working in the same way as described above.

[0044] It will be appreciated that the system requires two or more pressure sources to generate a certain number of output options. In this context, it should be noted that current washer systems already use two, three or four washer pumps on current vehicles and that this arrangement will multiply the number of individual outlets, allowing to individually clean a larger number of driver assistance devices, such as cameras, LIDARs and the like, without increasing of the number of pumps or pressure sources.Brief Description of the Drawings

[0045] Further details and advantages of the present invention will be apparent from the following detailed description of not limiting embodiments with reference to the attached drawing, wherein:Fig.1 (PRIOR ART) is a functional diagram of a simple form of a state of the art washer system;Fig.2 (PRIOR ART) is a functional diagram of a typical sensor cleaning system employing an electronic control unit controlling and driving electromechanical valves within the distribution block;Fig.3 is a functional diagram of a simplified embodiment of the fluid distribution system in accordance with the invention, employing three pumps, but with seven independently controllable outlets;Fig.4 is the ISO scheme of a hydraulically actuated 3 / 2-way pilot valve which may be employed in embodiments of the fluid distribution system;Fig.5 is the ISO scheme of a pneumatically actuated 3 / 2-way pilot valve which may be employed in embodiments of the fluid distribution system;Fig.6 is a schematic view of an embodiment of the cleaning system with two hydraulic pressure sources and two pilot valves, serving three outlets;Fig.7 is a schematic view of an embodiment of a cleaning system with three hydraulic pressure sources and six pilot valves, serving seven outlets;Fig.8 is a schematic view of an embodiment of a cleaning system with four hydraulic pressure sources and fourteen pilot valves, serving fifteen outlets;Fig.9 is a schematic view of an embodiment of the same pressure-actuated sensor cleaning system as in Fig. 7, but with 3 dual pressure sources (dual pumps) and 2 valve blocks (front and rear) providing a total of seven individual outlets in the front and seven individual outlets in the rear of a vehicle;Fig.10 shows a highly integrated embodiment of the cleaning system of Fig. 7, using piston type valve elements grouped by pressure source and in a compact enclosure;Fig.11 shows the embodiment of Fig.10 with pressure source B activated;Fig. 12 shows a possible design of a fluid distribution system.Description of Preferred Embodiments

[0046] In the following, a fluid distribution system and a cleaning system is discussed in relation to automotive applications; however, it will be appreciated that the invention is applicable to other fields and applications, such as industrial plant fluid handling, aerospace, and other environments requiring fluid usage at multiple / numerous locations, such as for irrigation or fluid-based inflation.

[0047] In this disclosure, like reference signs are used to denote like elements. Moreover, individual design elements, features or steps from one embodiment disclosed herein may be combined with one, some or all design elements, features or steps from another embodiment disclosed herein.

[0048] Fig. 3 is a functional diagram of a pressure-actuated fluid distribution system 40 in accordance with simplified embodiment of the invention. As in Fig. 1 (PRIOR ART) the system of Fig. 3 is based on three pumps 20 feeding three inlets 41 , but now with seven independently controllable outlets 60 of the fluid distribution system 40 corresponding to the seven logical combinations of binary pump operation, i.e.dependent upon which ones of fluid pressure sources A, B and C (collectively fluid pressure sources 20) are switched ON (e.g. using a controller or control system, not shown).

[0049] As discussed above, in embodiments, the fluid distribution system 40 employs multiple flow control devices, which are suitably in the form of pressure- actuated pilot valves.

[0050] Fig. 4 and Fig. 5 schematically show the functional principle of the hydraulic (50) and pneumatic (52) pressure-actuated valve, respectively. The most suitable valve type is a 3 / 2-way valve with 1 inlet port (IN) and 2 outlet ports, of which one is normally open (NO) and the other one is normally closed (NC). The pilot port (or control inlet) is connected to the pressure source. Without pressure at the pilot port, the NO outlet is open. When pilot pressure is applied, the internal valve element shifts and the valve outlets get inverted, whereby the NO outlet closes and the NC outlet opens. Thus, each valve has 2 states, ON and OFF, corresponding to the 2 possible outlets.

[0051] The principle and the construction of the individual valves is not subject to this invention. Therefore, commercially available valves or derivatives thereof may be suitable, with a variety of guiding, sealing and actuation elements, as long as actuation is based on fluid pressure.

[0052] Fig. 6 schematically shows an embodiment illustrating the fundamental principle of the fluid distribution system, with a valve arrangement in its simplest form - with two individually switchable fluid pressure sources 20A and 20B (collectively, fluid pressure sources 20) two inlets (41 ) and two pilot valves 50A and 50B (collectively, pilot valves 50) serving three outlets (60).

[0053] In embodiment of Fig. 6, each pressure source 20A and 20B has two functions. First, it delivers fluid pressure through the control inlets (also known as pilot port or pilot conduit) 42, transmitting the pressure and actuating the pilot valves 50 assigned to the respective pressure sources 20, e.g. by feeding a control inlet of the pilot valves. Thus, fluid pressure source 20A controls pilot valve 50A and fluid pressure source 20B controls pilot valve 50B. Secondly, each pressure source 20A and 20B delivers fluid flow to the distribution system through the flow conduits 44feeding the fluid into the distribution system 40 where it gets redirected to the desired (individual) outlet thereof.

[0054] The control inlets (or pilot ports) 42 do not deliver any fluid flow; they are dead-ended at the pilot port of the pilot valves 50A and 50B where they deliver the pressure signal actuating the valve motion with only minimal displacement of fluid.

[0055] The flow conduits 44 branch off to the control inlets 42 and merge to enter the distribution system 40 though the inlet of the first valve 50A in sequence. In this way, the inlet is always fed by at least one of the pressure sources 20A, 20B. It will be appreciated that in this configuration, the incoming pressure flows serve to individually control the pilot valves by their respective control inlets 42, and merge downstream internally to the distribution device to form a common supply flow 44 to be supplied to the output ports. As a result, the fluid distribution system does not require separate inlets 41 for control and flow, which makes this embodiment particularly efficient.

[0056] As seen in Fig. 6, in this embodiment the valves 50A and 50B are arranged in sequence. Consequently, pressure source 20A can actuate valve 50A, and pressure source 20B can actuate valve B through respective control inlets 42.

[0057] In certain embodiments, the non-return valves 70 are employed and are preferably passive reverse-flow protection devices preventing pressure from one pressure source 20A from interfering with the pilot feed of another pressure source 20B; otherwise, the system may not function properly.

[0058] In a first operating mode, only pressure source 20A is actuated (i.e. switched ON by a control system, not shown). Valve 50A opens and the flow is routed to valve 50B, which feeds (individual) outlet “A” (among outlets 60).

[0059] In a second operating mode, only pressure source 20B is actuated (i.e. switched ON by a control system, not shown). Valve 50A remains in default position and feeds outlet “B” (among outlets 60).

[0060] In a third operating mode, both pressure sources 20A and 20B are actuated (i.e. switched ON by a control system, not shown). Valve 50A opens and the flow is routed to valve 50B, and valve 50B also opens and feeds outlet “A+B” (among outlets 60).

[0061] In this manner, the three possible ON / OFF combinations of the two pressure sources 20A and 20B lead to three different outlets “A”, “B” and “A+B”.

[0062] Fig. 7 is a schematic view of an embodiment of a pressure-actuated fluid distribution system, in this case employing three (hydraulic) fluid pressure sources (A), (B) and (C) and six pilot valves, serving seven outlets corresponding to the seven possible logic combinations of pump activation. Fluid pressure source (A) controls one pilot valve in the upper row, fluid pressure source (B) controls two pilot valves in the middle row, and fluid pressure source (C) controls three pilot valves in the lower row. The operation of the individual pilot valves is the same as in the embodiment of Fig. 6, extended and varied as appropriate. In Fig. 7, with the system extended to three pressure sources and six pilot valves, the seven possible binary ON / OFF combinations of three pressure sources (A), (B) and (C) (i.e. as switched by a control system, not shown) correspond to seven different outlets - labelled A, B, C, A+B, A+C, B+C and A+B+C - being possible as the individual outlet.

[0063] Fig. 8 is a schematic view of an embodiment of a pressure-actuated fluid distribution system with four (hydraulic) fluid pressure sources (A), (B), (C) and (D) and fourteen pilot valves, serving fifteen outlets corresponding to the fifteen possible logic combinations of pump activation. Fluid pressure source (A) controls one pilot valve in the upper row, fluid pressure source (B) controls two pilot valves in the second row, fluid pressure source (C) controls four pilot valves in the third row and fluid pressure source (D) controls seven pilot valves in the bottom row. The operation of the pilot valves is the same as in the embodiment of Figs 6 and 7, extended and varied as appropriate. In Fig. 8, with the fluid distribution system extended to four pressure sources and fourteen valves, the fifteen binary ON / OFF combinations of four pressure sources (A), (B), (C) and (D) (i.e. as switched by a control system, not shown) correspond to fifteen different outlets - labelled A, B, C, D, A+B, A+C, A+D, B+C, B+D, C+D, A+B+C, A+B+D, A+C+D, B+C+D and A+B+C+D - being possible as the individual outlet.

[0064] Some combinations may drop out, for example when pressure sources are not independent. If, for example, fluid pressure sources (A) and (B) may only be actuated alternatively (i.e., either (A) or (B)), the outlets using the combination A+B would not be available.

[0065] On the other hand, if four bidirectional fluid pressure sources are used, such as four dual pumps, then two systems from Fig. 8 may be used with a total of 2x15=30 outlets controlled individually.

[0066] While the entire system is preferably sealed to the outside, it must be avoided to dispense fluid, more specifically liquid, at an undesired moment to an undesired location. More specifically, it must be ensured that the valves (50; see Fig. 6) reach their desired position / state prior to the feed flow arriving at their inlet.

[0067] To achieve this, it is preferable to arrange the conduits in such a way that the or each pressure source feeds the control inlets 42 first, and then is re-routed to the feed conduits 44.

[0068] This will provide two benefits: a) In the case of a liquid, it will allow any air or vapor to get purged from the control inlets 42. Since air and vapor are compressible, they may cause delays in building pressure, thus reducing the response time of the valves and leading to overall slower system response. b) The control inlets 42 are pressurized before the feed flow conduits 44 are pressurized. This allows the valves to move to their desired positions while the feed flow pressure is still building up. This way it is assured that all valves 50 will reach their desired position before any flow occurs, preventing any mis-routing of fluid to the wrong outlet.

[0069] In embodiments, the additional passive restrictions, more specifically the non-return valves 70 which may be installed between the control inlets 42 and the feed conduits 44, ensure pressure build-up in the pilot system before any flow buildup in the feed system.

[0070] The non-return valves (70) thus have a dual function: a) Prevent crossfeeding between control inlets 42 and b) provide a pressure gradient and delay to allow pilot system pressure build before fluid flow is established. It will be noted that these two functions may alternatively be provided by two separate flow devices: one check valve and one downstream pressure release valve or restrictor.

[0071] It is therefore preferable to have a conduit and valve arrangement as described to ensure proper functioning of the system.

[0072] The skilled person will appreciate that there are other ways to purge the pilot system of gas, e.g. through permeable membranes or other purge systems.

[0073] The system may also be equipped with additional hydraulic or pneumatic elements, like air springs on the feed side, with their simplest embodiment being a closed volume containing air, acting as damper for pressure peaks and also adding a time delay to compress the enclosed air volume, thus allowing more time for pilot pressure to push the valves 50 into their desired position before the flow and pressure builds up in the feed system and arrives at the (main feed) inlets of valves 50.

[0074] On the outlet side of the fluid distribution system 40, commonly used nozzles (not shown) or similar consumers, like telescopic nozzles (not shown) may be arranged. Typically, these outlets are equipped with state-of-the-art check valves (not shown) opening at a given overpressure to avoid dispensing fluid unintentionally due to static or dynamic pressure fluctuation in the system.

[0075] The skilled person will appreciate that the location and the restriction of such passive devices needs to be adapted in such a way that it prevents unintentional actuation without causing too much restriction or time delay.

[0076] In the described embodiments, the flow lines 44 are not vented after system activation and as such, unwanted fluid pressure may remain in the dispensing system. An additional pressure-actuated valve (not shown) at the last level (lowest level of pilot valves), in a normally-open (NO) position when all pressure sources 20 are off, may be provided in certain embodiments to create an open path on the flow side of the system, allowing to vent nozzles or telescopes that need to be vented to retract. This open path may be routed back to the fluid container 10.

[0077] There are other ways of venting or pressure release, for example through calibrated bleed orifices in the valves.

[0078] The skilled person will appreciate that, if multiple pumps (as fluid pressure sources) are actuated in parallel, the combined pressure and flow exceeds the one of a single pressure source. This may be compensated by controlling the pressure sources electrically or mechanically, if equipped with such capability, to achieve the desired total flow and pressure in the system.

[0079] On the other hand, the addition of pressure and flow may be used as a feature to assign higher flow and pressure outlets to larger consumers, like clusters of multiple (e.g. automotive) sensors cleaned together, or LIDARs with larger surfaces requiring higher fluid flows and multiple nozzles for cleaning across the entire surface. The cross sections of the flow conduits and valves may be sized in accordance with their respective fluid flows.

[0080] A skilled person will appreciate that if there is only a single source of flow and pressure, like a central pump, the distribution is typically achieved through electrically actuated valves, as shown in Fig.2. In this case, the pressure-actuated distribution system may still be used to multiply the output of 2, 3 or more valves to 3, 7 or more outlets respectively. Although such a configuration involves the use of electrically actuated valves, this will allow to limit the use of electromechanical devices to a minimum.

[0081] In addition to the 2, 3 or 4 single pressure sources used as examples to explain the principle, additional combinations of pressure sources are possible while maintaining the principle of flow control device (e.g. pilot-pressure) operated distribution. The only criteria is that individual pressure is available to shift the flow control devices (e.g. pilot valves) and that at least one pressure source delivers flow to the system.

[0082] For example, “dual pumps” exist on the market where the same electric motor and impeller can activate either one or another outlet, but not both at the time, through inversion of the rotation direction. These work as well with the abovedescribed pressure-actuated distribution system, but reduce the number of possible combinations due to the alternating pressure sources.

[0083] If the media is a gas, typically the gas is contained in a pressurized vessel or circuit and released through externally actuated valves, which take the role of the fluid pressure source in embodiments, with the valves actuated according to the described logic. Besides this, the pressure-actuated fluid distribution system will work in the same way as with liquid media.

[0084] Fig. 9 is a schematic view of an embodiment of the same pressure-actuated sensor liquid-based cleaning system as in Fig. 7, but with the 3 pressure sources being dual pumps supplying 2 separate distribution systems placed in the front andin the rear of a vehicle respectively. This embodiment is an example of the 3->7 system used in a decentralized way and providing 14 independent outlets with only 3 (dual) pumps.

[0085] Thus, in the embodiment of Fig. 9, when for example a vehicle comprises surfaces to be cleaned at a certain distance from each other, like front and rear of a larger vehicle, the arrangement may be de-centralized into two or more separate clusters, for example one in the front and another in the back of the vehicle, providing more effective cleaning.

[0086] Fig. 10 shows an embodiment of the pressure-actuated fluid distribution system as in Fig. 7, using piston type valve elements grouped by pressure source and interconnected with integrated pilot conduits (control inlets) and flow conduits.

[0087] As seen in Fig. 10, and according to most preferred embodiments, the arrangement of flow control devices (e.g. valves) forming the fluid distribution system is integrated in a common enclosure or body with internal channels or galleries guiding the fluid, and the valve elements 50 enclosed in such a way that no hoses and connectors are required, and a very compact arrangement is possible.

[0088] Furthermore, such integrated design may be constructed in a modular way allowing to integrate a variable number of valve elements following the needs of a specific application.

[0089] Fig. 11 shows the embodiment of Fig. 10 with pressure source B activated.

[0090] In alternative embodiments, multiple independent pressure-actuated systems may be fed by the same pressure sources.

[0091] Fig. 12 shows a possible design of a fluid distribution system with several features providing a number of benefits for size reduction, functionality, robustness, efficiency and manufacturability. It shows as an example a 3-pump system with pump B active, while A and C are inactive. The pressurized path is in black and the pressure-less (or unpressurized) cavities are in white.

[0092] The valves and pistons are designed and arranged such that all the connecting channels are straight, allowing to save space between the pistons and to simplify the housing for easy manufacturing. These channels may be carved fromthe sides while the complete valve body is a single block of material. This provides an easy way to manufacture an integrated distributor.

[0093] In the inlet side (pressure source inlets from the left), the non-return valves (70) shown in Fig. 10 and Fig. 11 are now integrated in the pistons. A single vertical collecting channel crosses all pistons, whereby it passes in-between 2 piston segments when the pistons are in closed (leftmost) position. When pressure is applied to a specific inlet, that piston moves and releases the incoming flow to the collector, while the pressure-less pistons remain in their closed position, isolating the pressure sources from each other and preventing any cross-talk.

[0094] This arrangement has the following additional benefits: no extra component or assembly is required to achieve the check function, packaging space is minimized, the feed path can only open after the valve piston has shifted, which ensures that the pistons reach their target position prior to any flow getting delivered.

[0095] An additional feature is the venting path. As the system relies on the pressure difference between pressure source side (pump pressure) and the opposite (pressure-less) side of the piston, that latter side must be vented to atmosphere or otherwise maintained at low pressure. The different pressure sides are separated by annular seals (shown in black on the piston elements).

[0096] In the same way, sealing is also required between the active flow conduits delivering fluid to the dispensing nozzles and the inactive conduits that are not supposed to deliver fluid, so those inactive conduits and cavities must be vented to atmosphere or otherwise maintained at low pressure. Any residual pressure in the conduits could lead to unwanted dispensing.

[0097] Venting is especially important when telescopic nozzles are used, as the retracting telescope is pushing fluid back to the system, so this volume needs to be able to return to a low pressure environment.

[0098] To achieve this, the following design is proposed (Fig.12):Hollow pistons with coaxial venting channels (represented with a dotted line) open to the right and connecting all pressure-less cavities to the vented springside cavities.All spring-side cavities connected and vented to a low pressure environment (“vent”).

[0099] This arrangement allows to maintain low pressure in all inactive conduits and evacuate leaked fluid through the vent line. No fluid volume can get trapped, as all cavities with changing volume (spring side) are permanently vented.

[0100] If the leakage media needs to be recovered (f.ex. hazardous or precious fluid), the vent may connect to a low pressure return line to take the leaked fluid back to the container or reservoir, providing a fully closed system. There are various ways to do this.

[0101] If the media is air (pneumatic control system) or an open water system (gardening), the vent line may simply drain off to the environment.

[0102] This provides an effective design for a very compact and robust distributor for automotive sensor cleaning and other applications.

[0103] These features apply equally to constructions with a different number of pressure sources and outlets, as well as for liquid and gaseous fluids.

[0104] A skilled person will appreciate that multiple other arrangements are possible while maintaining the same functional principle.

[0105] Moreover, in embodiments, the control of the system being through a digital ON / OFF combination of pumps, a control logic has to be suitably implemented. The skilled person will appreciate that such logic is extremely simple and may be composed of a basic arrangement or wires and switches, without any electronics involved. Alternatively, a software or firmware-based controller may be employed.

[0106] Other benefits described in context with the vehicle according to the invention apply to the corresponding method to the full extent.

[0107] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered exemplary and not limitative; the invention is not limited to the disclosed embodiments.

[0108] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. Moreover, in the claims,the words “comprising”, “composed of”, “containing” or “including” do not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality, which is meant to express a quantity of at least two.List of Reference Symbols10 Fluid reservoir20 Pressure source (pump or valve)30 Electrically powered distribution system32 Electronic control unit40 Pressure-actuated distribution system41 Inlet (or input port)42 Control inlet44 Flow conduit50 Pilot-actuated hydraulic 3 / 2-way valve52 Pilot-actuated pneumatic 3 / 2-way valve60 Outlet I output port70 Non-return valve and restrictor

Claims

Claims1 . A fluid distribution system configured to control the flow of cleaning fluid to output ports thereof, the fluid distribution system comprising: a plurality of input ports, each input port being configured to be connected to a respective pressure source for receiving a flow of the cleaning fluid therefrom; a plurality of flow control devices configured to distribute the flow of the cleaning fluid received at one, a subset or all of the input ports; and a plurality of outlet ports, each outlet port being configured to receive cleaning fluid via one, a predeterm ined subset or all of the plurality of flow control devices; wherein the plurality of flow control devices are configured to direct, at a given time, the flow of the cleaning fluid to an individual outlet to clean an element corresponding to the individual outlet, characterized in that each flow control device is configured to direct incoming cleaning fluid flow received at an inlet of the flow control device to one of two separate outlets of the flow control device, depending on whether the cleaning fluid is received at the flow control device under pressure from one of the pressure sources or not, such that the individual outlet is dependent upon which one or ones of the plurality of input ports is currently receiving the cleaning fluid under pressure from a respective pressure source.

2. The fluid distribution system of claim 1 , wherein each flow control device comprises a shiftable element configured to direct incoming cleaning fluid flow received at the inlet of the flow control device to one of the two separate outlets of the flow control device, whereby shifting is achieved by a transition from (i) the cleaning fluid not being received under pressure at the flow control device from one of the pressure sources to (ii) the cleaning fluid being received under pressure from one of the pressure sources, or vice versa.

3. The fluid distribution system of claim 2, wherein each flow control device comprises (i) a main inlet for receiving a flow of cleaning fluid for direction to one of the outlets of the flow control device and (ii) a control inlet for receiving the cleaning fluid for controlling the shiftable element.

4. The fluid distribution system of claim 1 , 2 or 3, wherein, for at least one of the inlet ports, the fluid flow arriving from the respective pressure source is routed through a first flow control device and subsequently through at least one additional flow control device.

5. The fluid distribution system of any of claims 1 to 4, wherein, for at least one of the inlet ports, the inlet port is connected to a series of flow control devices whereby each flow control device in the series is controlled by one of the pressure sources corresponding to that inlet port.

6. The fluid distribution system of any of claims 1 to 5, wherein the flow control devices are interconnected via fluid conduits such that the flow of the cleaning fluid is directable to any of the outlets to individually clean a corresponding element.

7. The fluid distribution system of any of claims 1 to 6, wherein, at a given time, each of the inlet ports is configured for, independently of the other inlet ports, either receiving the cleaning fluid under pressure or not receiving the cleaning fluid, corresponding to the respective pressure source individually being turned ON or OFF, respectively, whereby a plurality of different configurations of the states of the flow control devices is possible, the state being either that of allowing flow or that of blocking flow.

8. The fluid distribution system of claim 7, wherein each of the plurality of different configurations of the states of the flow control devices corresponds to a different individual outlet, and the number of different individual outlets is less than or equal to the number of combinations of the inlet ports either receiving the cleaning fluid under pressure or not receiving the cleaning fluid, corresponding to the respective pressure source individually being turned ON or OFF, respectively.

9. The fluid distribution system of any of the preceding claims, further comprising, for each of the inlet ports, a respective non-return valve between the inlet port and a point disposed upstream of the plurality of flow control devices at which flows arriving from multiple pressure sources merge.

10. The fluid distribution system of any of the preceding claims, wherein the flow control devices are combined and integrated in one or several interconnected enclosures.11 . The fluid distribution system of any of the preceding claims, wherein the fluid comprises a liquid and at least one of the plurality of flow control devices is actuated by hydraulic pressure supplied by one or more of the pressure sources.

12. The fluid distribution system of any of claims 1 to 10, wherein the fluid comprises a gas and at least one of the plurality of flow control devices is actuated by pneumatic pressure supplied by one or more of the pressure sources.

13. A cleaning system for cleaning each of a plurality of elements, the cleaning system comprising: one or more containers configured to store and supply cleaning fluid; at least two pressure sources configured to deliver cleaning fluid stored in the one or more containers whereby, in use, the cleaning fluid may be delivered under pressure; and a control system configured to turn ON or OFF, at a given time, each of the pressure sources independently of the other pressure sources; the fluid distribution system of any of claims 1 to 12, each input port thereof being connected to a respective pressure source; a plurality of nozzles, each nozzle being configured to receive cleaning fluid from a respective one of the outlet ports of the fluid distribution system and to direct the cleaning fluid onto a respective element; wherein the control system is configured, at a given time, to turn ON one, a subset or all of the pressure sources, with the other pressure sources remaining OFF, whereby the one or ones of the plurality of input ports of the fluid distribution system that are currently receiving the cleaning fluid under pressure correspond to the or those pressure sources that are turned ON; and whereby a nozzle, among the plurality of nozzles, corresponding to the individual outlet is caused to dispense the cleaning fluid to clean the element corresponding to the individual outlet.

14. The cleaning system of claim 13, wherein each pressure source is configured to be turned ON or OFF individually such that multiple combinations of ON and OFF pressure sources may be defined.

15. The cleaning system of claim 14, wherein the number of individual outlet ports is less than or equal to the number of possible ON / OFF combinations of pressure sources.

16. The cleaning system of any one of claims 13 to 15, wherein the control system is configured to: receive a command identifying an element, nozzle or outlet port; access a mapping in a storage, the mapping defining an association between (i) each element, nozzle or outlet port and (ii) a predetermined combination of pressure sources; retrieve using the mapping the predetermined combination corresponding to the identified element, nozzle or outlet port; wherein turning ON, at a given time, by the control system, one, a subset or all of the pressure sources, with the other pressure sources remaining OFF, is performed based upon the retrieved predetermined combination.

17. An automotive vehicle, comprising: the cleaning system of any of claims 13 to 16, wherein each of a plurality of elements comprises an optical surface of the vehicle.

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