Vehicle wheel and a method for controlling a vehicle

Abstract

A wheel for a vehicle includes a tyre and a rim for supporting the tyre. A chamber is defined between the tyre and the rim for receiving pressurized air. The wheel further includes a detecting device located inside the chamber for detecting presence of water in the wheel.

Claims

1. A method for controlling tyre pressure in a wheel, the method comprising the following steps: detecting whether water is present inside a chamber defined between a tyre and a rim of the wheel; measuring pressure inside said chamber; if no water is present inside the chamber and if pressure (Pw) measured inside the chamber is different from a target pressure value (PwT), activating a tyre inflation system for inflating or deflating the tyre in order to bring pressure inside the chamber at the target pressure value (PwT); and setting a limit to vehicle speed if water is detected inside the chamber.

2. The method of claim 1, wherein the tyre inflation system is disabled if water is detected inside the chamber.

3. The method of claim 1, wherein presence of water inside the chamber is determined by means of a detecting device located in the chamber, the detecting device comprising a humidity sensor.

4. The method of claim 3, wherein the detecting device further comprises a pressure sensor for measuring pressure inside the chamber in order to monitor said pressure and activate the tyre inflation system, if needed.

5. The method of claim 3, wherein the detecting device further comprises a temperature sensor for detecting temperature inside the chamber.

6. A method for controlling tyre pressure in a wheel, the method comprising the following steps: detecting whether water is present inside a chamber defined between a tyre and a rim of the wheel; measuring pressure inside said chamber; if no water is present inside the chamber and if pressure (Pw) measured inside the chamber is different from a target pressure value (PwT), activating a tyre inflation system for inflating or deflating the tyre in order to bring pressure inside the chamber at the target pressure value (PwT), wherein a warning signal is generated if water is detected inside the chamber.

7. The method of claim 6, wherein the tyre inflation system is disabled if water is detected inside the chamber.

8. The method of claim 6, further comprising setting a limit to vehicle speed if water is detected inside the chamber.

9. The method of claim 6, wherein presence of water inside the chamber is determined by means of a detecting device located in the chamber, the detecting device comprising a humidity sensor.

10. The method of claim 9, wherein the detecting device further comprises a pressure sensor for measuring pressure inside the chamber in order to monitor said pressure and activate the tyre inflation system, if needed.

11. The method of claim 9, wherein the detecting device further comprises a temperature sensor for detecting temperature inside the chamber.

Description

(1) The invention will be better understood and carried out with reference to the attached drawings that show an exemplifying and non limiting embodiment thereof, in which:

(2) FIG. 1 is a schematic and interrupted cross section, showing a portion of a wheel of a vehicle;

(3) FIG. 2 is a flow chart showing the steps of a method for controlling a vehicle.

(4) FIG. 1 shows a portion of a wheel 1 of a vehicle, particularly an industrial or agricultural vehicle such as a tractor. The wheel 1 comprises a tyre 2 mounted on a rim 3. Inside the wheel 1, i.e. between the tyre 2 and the rim 3, a chamber 4 is defined. The chamber 4 is intended to receive pressurized air, which may be sent inside the chamber 4 through a valve 5 provided on the rim 3.

(5) Air can be sent inside the chamber 4, and the tyre 2 can thus be inflated, either manually or automatically. In the latter case, a tyre inflation system (TIS) is provided on the vehicle for automatically sending pressurized air inside the chamber 4 so as to inflate the tyre 2. The tyre inflation system may further be configured to deflate the tyre 2 in case an excessive pressure is present inside the chamber 4.

(6) A control unit is provided for controlling the tyre inflation system.

(7) The rim 3 comprises a central portion 6, shown only partially in FIG. 1, which is intended to be fastened to a hub of the vehicle. The rim 3 further comprises a tyre supporting portion 7, suitable for engaging with the tyre 2 in order to support the latter. The tyre supporting portion 7 may comprise two end grooves 8, each one of which is intended to receive an edge of the tyre 2.

(8) Inside the wheel 1, a detecting device 9 is provided, shown only schematically in FIG. 1. The detecting device 9 is housed inside the chamber 4. In particular, the detecting device 9 may be attached, e.g. by gluing, to a zone of the supporting portion 7 interposed between the end grooves 8, The detecting device 9 thus projects inside the chamber 4.

(9) The detecting device 9 comprises a humidity sensor for detecting whether or not water is present inside the chamber 4. It may actually happen that the driver, in order to increase weight of the tractor and hence adherence thereof to the ground, introduces a certain quantity of water inside the wheel 1. The humidity sensor is capable of detecting whether this has occurred.

(10) The detecting device 9 further comprises a pressure sensor for measuring air pressure inside the chamber 4. Furthermore, the detecting device 9 may comprise a temperature sensor for measuring temperature inside the chamber 4. The signals provided by the pressure sensor and the temperature sensor, which are indicative respectively of pressure and temperature measured inside the wheel 1, are intended to be processed by the tyre inflation system in order to determine whether and to which extent the tyre 2 has to be inflated or deflated by the tyre inflation system.

(11) In order to work properly even if water has been introduced inside the wheel 1, the humidity sensor is water proof. The whole detecting device 9 may be water proof. For example, the humidity sensor, the pressure sensor and the temperature sensor may be housed inside a common water proof housing.

(12) The detecting device 9 is configured to communicate with the control unit, for example via wireless means for communication. The wireless means for communication may comprise a wi-fi connection. Thus, the detecting device 9 is capable of transmitting to the control unit the values of humidity, pressure and temperature measured inside the chamber 4.

(13) The control unit is capable of converting the signals received from the detecting device 9 into messages of a particular format, for example into CAN messages. The so converted messages can be shared on a vehicle CAN bus which receives and transmits information concerning the operation of the vehicle.

(14) The detecting device 9 operates and is controlled according to the steps of the method shown in FIG. 2.

(15) In a first step of the method, the control unit determines whether water is present in the chamber 4. To this end, a signal WW derived from the humidity sensor is read by the control unit. The signal WW may either be zero, which implies that no water is present inside the wheel 1, or have a value greater than zero, which means that water has been detected inside the wheel 1.

(16) Furthermore, pressure is measured inside the wheel 1 by means of the pressure sensor included in the detecting device 9. Temperature inside the wheel 1 may further be measured by means of the temperature sensor.

(17) A parameter Pw that is indicative of air pressure inside the wheel 1, which can be calculated by taking into consideration the signals received by both the pressure sensor and the temperature sensor, is read by the control unit.

(18) If it is found that the condition WW=0 is not satisfied, than water is present inside the wheel 1.

(19) In this case, the method may comprise the step of generating a warning message intended to warn the driver that water is present inside the wheel 1. The warning message can be displayed on a control panel of the vehicle.

(20) Furthermore, if it is found that the condition WW=0 is not satisfied, the tyre inflation system is disabled. It is thus avoided that water inside the wheel 1 may jeopardize proper operation of the tyre inflation system, or damage components thereof.

(21) The method shown in FIG. 2 also comprises the step of limiting the speed of the vehicle (VS) if it is found that WW0. In this case, the control unit acts in such a way that the speed of the vehicle cannot exceed a certain threshold. Safety for the driver is thus increased, because it is ensured that the vehicle cannot reach dangerous speeds if water is detected inside the wheel 1.

(22) If, on the other hand, it is found that water is not present inside the wheel 1, i.e. the condition WW=0 is satisfied, then the control unit does not limit the vehicle speed. In this case, the vehicle can travel at any speed chosen by the driver, because no water inside the wheel 1 jeopardizes safety of the vehicle.

(23) Furthermore, in case WW=0, the parameter Pw indicative of air pressure in the chamber 4 is compared with an air pressure target value PwT, i.e. a value of pressure inside the wheel 1 which is considered to be optimal.

(24) If it is found that PwPwT, then the tyre inflation system is activated to bring pressure inside the wheel at a value which is as close as possible to the target value PwT.

(25) If on the other hand it is found that Pw=PwT, no action is taken, because pressure inside the wheel is already at an optimal value.