WO2003002378A1

WO2003002378A1 - Intelligent control of vehicle functions

Info

Publication number: WO2003002378A1
Application number: PCT/GB2002/002901
Authority: WO
Inventors: Jeremy John Greenwood; Kevin Trevor Talbot; Stephen Paul Nicholls
Original assignee: Ford Global Technologies, Llc.
Priority date: 2001-06-28
Filing date: 2002-06-25
Publication date: 2003-01-09
Also published as: GB2376929B; GB2376929A; GB0115748D0

Abstract

Apparatus for determining that a vehicle is at least partially immersed in a liquid and responding thereto, the apparatus comprising one or more sensors (14) for detecting a condition of the vehicle and for outputting a signal in response to a detected condition, a processor (16) arranged to receive a signal output from the sensors, to determine, on the basis of the signal, whether a detected condition of the vehicle indicates that the vehicle is likely to be at least partially immersed in a liquid, and to output a signal to control the functioning of a vehicle function in response to the determination.

Description

Intelligent Control of Vehicle Functions

Field of the Present Invention

The present invention relates to methods, computer programs and apparatus for intelligently controlling vehicle operations or functions in response to detected conditions.

Background

When motorised vehicles, such as motorcars, are driven through sufficiently deep water, water may pass through the radiator grille and flow into the fan or ventilation system of the vehicle engine. If the fan or ventilation system is operating, the water is thrown over the engine compartment and the alternator may be flooded while rotating at high speed. Other undesirable consequences may result, such as electrical problems, rusting, inefficient engine performance, and so on. Furthermore, if water comes over the bonnet of the vehicle and into the ventilation system while the fan is running, the fan may stall and may even blow a fuse. With the fan or ventilation system disabled, the vehicle may not be safely driven.

Systems for detecting the presence of objects external to vehicles are known. US Patent Number 5,978,736 describes a vehicle obstruction detection system. One or more sensors, such as ultrasonic or infrared transducers, are fitted to a vehicle and detect the proximity of external objects to assist a driver when manoeuvring the vehicle, for instance when parking. US Patent Number 5,629,690 describes a method of fitting hidden sensors for vehicle obstruction detection systems.

Summary of the Present Invention

According to a first aspect of the present invention there is provided apparatus for determining that a vehicle is at least partially immersed in a liquid and responding thereto, the apparatus comprising: one or more sensors for detecting a condition of the vehicle and for outputting a signal in response to a detected condition; a processor arranged to receive a signal output from the one or more sensors, to determine, on the basis of the signal, whether a detected condition of the vehicle indicates that the vehicle is likely to be at least partially immersed in a liquid, and to output a signal to control the functioning of a vehicle function in response to the determination.

Advantageously, the present invention allows for appropriate measures to be taken when it is determined that a vehicle is wading to prevent or remedy some of the undesirable and potentially dangerous consequences described above. Preferably, the apparatus comprises a processor arranged to receive a signal output from the sensors, and to determine, on the basis of the signal, whether a detected condition of the vehicle indicates a vehicle state other than that the vehicle is at least partially immersed in a liquid. Thus, apparatus, such as the one or more sensors or the processor, may be present in the vehicle for vehicle systems other than immersion detection. Thus, the present invention may be implemented by at least partially re-using known or standard equipment. For instance, the vehicle may be equipped with a prior art parking aid system such as described above and present invention may be implemented by using the output of the parking aid sensors.

Preferably, the sensors are attached to the vehicle and detect proximity of objects external to the vehicle and the determination that the vehicle is at least partially immersed in a liquid depends on the detection of an object at approximately zero distance. There are few solid objects that can be positioned so as to be approximately at a zero distance from a sensor attached to a vehicle, for example at a bumper. Liquids such as water are more likely to be detected at a zero distance because of their fluid properties. Thus, detection of an object at approximately a zero distance is a probable indicator of immersion or wading in a liquid. More preferably, the apparatus comprises at least two sensors and the determination that the vehicle is at least partially immersed in a liquid depends on the substantially simultaneous detection of objects at approximately zero distance at at least two sensors. Greater certainty may be achieved using two or more sensors because the probability of a solid object simultaneously being positioned at a zero distance from two sensors or the probability of two solid objects simultaneously being positioned at zero distances from two sensors is even lower. Again, only liquids are likely to be detected at zero distances from two or more sensors because of their fluid properties. Also preferably, the processor for determining whether the vehicle is at least partially immersed in a liquid is arranged to receive one or more other input signals representing one or more current conditions selected from the following: a speed of the vehicle, a temperature external to the vehicle, a temperature of at least part of the vehicle, a humidity of at least part of the vehicle, a condition indicating rain, and whether the vehicle is in a user- selected "on road" or "off road" state, and wherein the determination that the vehicle is at least partially immersed in a liquid depends on the one or more other input signals. Even greater certainty may be achieved by taking into account other detected conditions. For example, rain and misting detectors are known and the presence of rain or misting may lead to a higher probability threshold for determining that the vehicle is at least partially immersed in a liquid. Similarly, the user-selected "on road" or "off road" state of the vehicle is a good indicator of general driving circumstances in which wading may occur and may advantageously be taken into account by the determining processor.

Preferably, the control signal is to control the functioning of one or more vehicle functions selected from the following: a ventilation function, an engine cooling fan function, and a vehicle suspension function. Thus, for example, on detection of a wading event, the engine ventilation flaps may be closed or switched from a summer to a winter path or vice verse to prevent ingress of water into the engine compartment, the fan may be switched off to prevent water being thrown over the engine compartment, the temperature thresholds of radiator cooling functions such as fan operation may be changed to take into account the wading event, and the ride height may be adjusted to raise the vehicle at least partially above the water level.

According to a second aspect of the present invention, there is provided a method of determining that a vehicle is at least partially immersed in a liquid and of responding thereto, the method comprising the following steps: detecting a condition of the vehicle using one or more sensors; determining whether the detected condition of the vehicle indicates that the vehicle is likely to be at least partially immersed in a liquid, controlling the functioning of one or more vehicle functions in response to the determination.

Advantages of the second aspect of the present invention are similar to those described above.

Further apparatus and computer programs for performing the method of the first aspect are also provided.

Other aspects of the present invention are set out in the appended claims and corresponding advantages are similar to those described above.

There now follows, by way of example only, a detailed description of preferred embodiments of the present invention in which:

Brief Description of Diagrams

Figure 1 is a schematic diagram of a motor car equipped with ultrasonic parking distance sensors for carrying out an embodiment of the present invention;

Figure 2 is a block diagram showing the functional linking of various vehicle components for carrying out an embodiment of the present invention;

Figure 3 is a flow diagram showing an exemplary process followed by a vehicle processor for carrying out an embodiment of the present invention;

Detailed Description of Embodiments of the Present Invention

Figure 1 is a schematic diagram of a motor car equipped with ultrasonic parking distance sensors for carrying out an embodiment of the present invention. Motor car 10 is a conventional motor car of a type suitable for on and off road driving. Motor car 10 comprises a front bumper 12 positioned in front of the engine and below the level of the bonnet. Front bumper 12 comprises two ultrasonic parking distance sensors 14 of a conventional type spaced apart from each other. For example, each sensor 14 comprises a vibrating diaphragm facing out from bumper 12 with a piezoelectric element behind it. The same diaphragm is used to send out and receive reflected ultrasonic signals. The transmission and reception of ultrasonic signals is controlled by an integrated circuit (ASIC) at each of the sensors, which may send signals to an electronic control unit for processing. The timing difference between transmission and reception gives a measure of the distance to an object. Typically there will also be two sensors (not shown) positioned on the rear bumper of motor car 10.

Figure 2 is a block diagram showing the functional linking of various vehicle components for carrying out an embodiment of the present invention. Ultrasonic parking distance sensors 14 are connected to parking distance warning electronic control unit 16 which receives the electronic signals output by the integrated circuit of each parking distance sensor 14. Conventionally, electronic control unit 16 processes the signals received to determine the proximity of solid objects, such as walls or other vehicles, to assist a driver in parking the motor car. Electronic control unit 16 is connected to sounder 18 and may be arranged to control the generation of a warning sound when an object is detected at less than a predetermined threshold distance.

According to an embodiment of the present invention, electronic control unit 16 is adapted to determine that the vehicle is at least partially immersed in a liquid or is wading through a liquid. When an object comes into contact with one of sensors 14, vibration of the diaphragm is attenuated and the sensor detects the presence of an object at zero distance. This occurs when the sensor is under water. Electronic control unit 16, receiving signals from one or more sensors detecting an object at a zero distance, may determine that the vehicle is at least partially immersed in a liquid or is wading through a liquid and generate appropriate responses. In a simple embodiment of the determination process, detection of an object at zero distance at any one of sensors 14 may be used as an indicator that the vehicle is at least partially immersed in a liquid or is wading through a liquid. It is unlikely that solid objects, such as walls or other vehicles, will be located at a zero distance from one of sensors 14, especially if the sensors are partially recessed from the front of the bumper. This is because it is unlikely that a solid object be of a shape such that it may come into contact with the sensor without first coming into contact with a more forward part of the bumper. Liquids, on the other hand, may come into contact with a sensor whether recessed or not because of their fluid properties. Thus, it is more likely that an object detected at a zero distance at one of sensors 14 is a liquid.

In a preferred embodiment, electronic control unit 16 is arranged to determine that the vehicle is at least partially immersed in a liquid or is wading through a liquid when signals from a plurality of sensors 14 indicate that at least two sensors are simultaneously detecting an object at a zero distance. It is statistically highly unlikely that a solid object could come into contact with two or more sensors at the same time, so accuracy of determination can be improved with this approach. In a further preferred embodiment, electronic control unit 16 is arranged to determine that the vehicle is at least partially immersed in a liquid or is wading through a liquid in dependence on signals received from other sensors or other electronic devices present in the vehicle such as a conventional rain sensor 38 which is connected to electronic control unit 16 over vehicle network 20. The detection of rain may indicate that a positive determination of wading is incorrect. Criteria used by electronic control unit 16 to make such a determination on the basis of the received signals from sensors 14 may be varied in dependence on the reception of a signal indicating rain. For example, the period of time over which continuous reception of signals from two or more sensors 14 detecting objects at zero distance is taken by electronic control unit 16 to indicate wading may be increased if rain is detected. Other signals received from other sensors or devices indicating other vehicle conditions may be taken into account, such as a speed of the vehicle, a temperature external to the vehicle, a temperature of at least part of the vehicle, a humidity of at least part of the vehicle, a condition indicating rain, and whether the vehicle is in a user-selected "on road" or "off road" state.

As mentioned above, electronic control unit 16 is connected to vehicle network 20. This is a conventional data network used in vehicles for interconnecting various electronic devices which may send and receive data messages which are handled by message centre 22. Via vehicle network 20, electronic control unit may receive signals for input into the process of determining that the vehicle is at least partially immersed in a liquid or is wading through a liquid. Also, via vehicle network 20, electronic control unit may send instructions to other electronic devices control to control the performance or functioning of vehicle functions or operations in response to determining that the vehicle is at least partially immersed in a liquid or is wading through a liquid. For example, heating and ventilation control unit 24 is connected to vehicle network 20 and controls the operation of heater fan 26 and re-circulation flaps control unit 28. In one embodiment, in response to determining that that the vehicle is at least partially immersed in a liquid or is wading through a liquid, electronic control unit 16 sends control signals to heating and ventilation control unit 24 to control vehicle ventilation and air intake. Thus, the engine ventilation flaps may be closed or switched from a summer to a winter path or vice verse to prevent ingress of water into the engine compartment during wading.

Similarly, suspension control unit 30 is connected to vehicle network 20 and controls the operation of and receives signals from ride height actuators and position sensors 32. In one embodiment, in response to determining that that the vehicle is at least partially immersed in a liquid or is wading through a liquid, electronic control unit 16 sends control signals to suspension control unit 30 to control vehicle ride height. Thus, the ride height may be adjusted to raise the vehicle at least partially above the water level. Similarly, engine control unit 34 is connected to vehicle network 20 and controls the operation of engine cooling fan 36, amongst other things. In one embodiment, in response to determining that that the vehicle is at least partially immersed in a liquid or is wading through a liquid, electronic control unit 16 sends control signals to engine control unit 34 to control the functioning of the engine cooling fan. Thus, the engine cooling fan may be switched off for the first 5 seconds of wading to prevent water being thrown over the engine compartment, and the temperature thresholds of radiator cooling functions including fan operation may be changed during the wading event. Figure 3 is a flow diagram showing an exemplary process followed by a vehicle processor for carrying out an embodiment of the present invention. Signals received via vehicle network 20 from other sensors or electronic devices may be taken into account by electronic control unit 16 when determining an appropriate response to a determination that the vehicle is at least partially immersed in a liquid or is wading through a liquid. Alternatively, electronic control unit 16 may send signals indicating the wading event to other control units or processors to inform their processes. For instance, the occurrence of a wading event may be taken into account by engine control unit 34 as well as engine temperature and vehicle speed when controlling the functioning of the engine cooling fan. Figure 3 shows an exemplary process followed by engine control unit 34 to determine the functioning of the engine cooling fan in response to the detection of a wading event and in dependence on the engine temperature and vehicle speed. At step 40, the process determines whether a wading event is occurring, as has been described above, in response to signals received from electronic control unit 16. If a wading event is occurring, the process continues to step 42 where it is determined whether the vehicle speed is above 15 miles per hour. If not, the process continues to step 44 where it is determined whether the engine temperature is above 108 degrees Celsius. If yes, the process continues to step 46 where it is determined whether the first 15 seconds of the wading event occurred during the last two minutes. If not, the process continues to step 48 where the engine cooling fan is controlled to operate and the process returns to step 40. If however, at step 46 it is determined that the first 15 seconds of the wading event did occur during the last two minutes, the process continues to step 50 where the engine cooling fan is controlled not to operate and the process returns to step 40. Similarly, if at step 44 it is determined that the engine temperature is not above 108 degrees Celsius, the process continues to step 50 where the engine cooling fan is controlled not to operate and the process returns to step 40. If, at step 42 it is determined that the vehicle speed is above 15 miles per hour, or if at step 40 it is determined that no wading event is occurring, the process continues to step 52 where it is determined whether the engine temperature is above 104 degrees Celsius. If yes, the process continues to step 54 where the engine cooling fan is controlled to operate and the process returns to step 40. If not, the process continues to step 50 where the engine cooling fan is controlled not to operate and the process returns to step 40.

Thus it can be seen that the functioning of the engine cooling fan may be controlled in dependence on the detection of a wading event as well as in dependence on the engine temperature and vehicle speed. It will be apparent that other vehicle functions, such as the ride height, ventilation and heating, may be similarly controlled in dependence on the detection of a wading event as well as in dependence on other vehicle conditions relevant to the particular functions.

Other variations and modifications to the present invention, within the capacity of the person skilled in the art, are envisaged, which invention is set out in the appended claims.

Claims

1. Apparatus for determining that a vehicle is at least partially immersed in a liquid and responding thereto, the apparatus comprising: one or more sensors for detecting a condition of the vehicle and for outputting a signal in response to a detected condition; a processor arranged to receive a signal output from the sensors, to determine, on the basis of the signal, whether a detected condition of the vehicle indicates that the vehicle is likely to be at least partially immersed in a liquid, and to output a signal to control the functioning of a vehicle function in response to the determination.

2. Apparatus according to claim 1 , comprising a processor arranged to receive a signal output from the sensors, and to determine, on the basis of the signal, whether a detected condition of the vehicle indicates a vehicle state other than that the vehicle is at least partially immersed in a liquid.

3. Apparatus according to claim 2, wherein the vehicle state relates to the position of the vehicle relative to external solid objects.

4. Apparatus according to any preceding claim, wherein the sensors are attached to the vehicle and detect proximity of objects external to the vehicle.

5. Apparatus according to claim 4, wherein the determination that the vehicle is at least partially immersed in a liquid depends on the detection of an object at approximately zero distance.

6. Apparatus according to claim 5, comprising at least two sensors wherein the determination that the vehicle is at least partially immersed in a liquid depends on the substantially simultaneous detection of objects at approximately zero distance at at least two sensors.

7. Apparatus according to any preceding claim, wherein the sensors are located at a bumper of the vehicle.

8. Apparatus according to any preceding claim, wherein the processor for determining whether the vehicle is at least partially immersed in a liquid is arranged to receive one or more other input signals representing one or more current conditions selected from the following: a speed of the vehicle, a temperature external to the vehicle, a temperature of at least part of the vehicle, a humidity of at least part of the vehicle, a condition indicating rain, and whether the vehicle is in a user-selected "on road" or "off road" state, and wherein the determination that the vehicle is at least partially immersed in a liquid depends on the one or more other input signals.

9. Apparatus according to any preceding claim, wherein the control signal is to control the functioning of one or more vehicle functions selected from the following: a ventilation function, an engine cooling fan function, and a vehicle suspension function.

10. Apparatus according to any preceding claim, comprising a processor for controlling the functioning of one or more vehicle functions, the processor receiving the control signal and controlling the functioning of one or more vehicle functions in dependence on the received control signal.

11. A method of determining that a vehicle is at least partially immersed in a liquid and of responding thereto, the method comprising the following steps: detecting a condition of the vehicle using one or more sensors; determining whether the detected condition of the vehicle indicates that the vehicle is likely to be at least partially immersed in a liquid, controlling the functioning of one or more vehicle functions in response to the determination.

12. A method according to claim 11 , comprising determining whether the detected condition of the vehicle indicates a vehicle state other than that the vehicle is at least partially immersed in a liquid.

13. A method according to claim 12, wherein the vehicle state relates to the position of the vehicle relative to external solid objects.

14. A method according to any of claims 11 to 13, wherein the sensors detect proximity of objects external to the vehicle.

15. A method according to claim 14, wherein the step of determining depends on the detection of an object at approximately zero distance.

16. A method according to claim 15, wherein the sensors comprise at least two sensors and the step of determining depends on the substantially simultaneous detection of objects at approximately zero distance at at least two sensors.

17. A method according to any of claims 11 to 16, wherein the sensors are located at a bumper of the vehicle.

18. A method according to any of claims 11 to 17, wherein the step of determining is dependent on one or more current conditions selected from the following: a speed of the vehicle, a temperature external to the vehicle, a temperature of at least part of the vehicle, a humidity of at least part of the vehicle, a condition indicating rain, and whether the vehicle is in a user- selected "on road" or "off road" state.

19. A method according to any of claims 11 to 18, wherein the one or more vehicle functions are one or more selected from the following: a ventilation function, an engine cooling fan function, and a vehicle suspension function.

20. Apparatus arranged to perform the method of any of claims 11 to 19.

21. A computer program arranged to perform the method of any of claims 11 to 19.