Abstract:
A vehicle ( 100 ) comprising a wading information display ( 1020 ), a memory and a processor, the memory containing a program configured to run on the processor to calculate the maximum wading depth of the vehicle from the measured suspension travel, and to display the maximum wading depth on the display. The display may also show a dual wading depth, an advisory wading speed, and vehicle inclination.

Description:
TECHNICAL FIELD 
       [0001]    The present invention is concerned with a human machine interface for displaying the water level relative to a vehicle body. More particularly, but not exclusively, the present invention is concerned with display of the water level of a wading vehicle and providing such information to a driver of the vehicle. Aspects of the invention relate to a vehicle comprising a wading information display, a method and a system. 
       BACKGROUND 
       [0002]    An off-road vehicle may be defined as a road vehicle having some off road capability—such as the provision of all wheel drive. Off road vehicles are often required to travel through water to reach their intended destination. Travel through deep water (typically over about 0.3 m in depth) is known as “wading”. Known off-road vehicles are designed to wade, and comprise suitably sealed closures to avoid ingress of water into the passenger compartment. The engine air intake is positioned at an elevated position (normally directly in front of and below the windscreen) to prevent water being ingested into the engine, and this intake will often dictate the maximum level of water relative to the body that the vehicle can wade through. 
         [0003]    Prior art methods of determining if the water level is safe to wade through include referring to depth gauges, e.g. permanent graduated poles situated within the water in the case of fords and measurement of the depth by the driver using a partially submerged stick or pole. 
         [0004]    As discussed, the maximum wading depth is determined by the position of a point on the vehicle body (e.g. the engine air intake). Because the ride height of the vehicle is often variable (due to the variable height of the suspension system) the permissible absolute depth of water which the vehicle can wade through varies depending on the selected ride height of the suspension system. 
         [0005]    The behaviour of the water around a wading vehicle is influenced by the vehicle&#39;s speed. The driver will typically want to travel as fast as possible (to reach a destination) but high speed travel whilst wading is not advisable. Waves from the vehicle may damage surrounding structures (and lap over e.g. flood defences) and excessive speed may cause waves to lap over the vehicle itself, entering e.g. the engine air intake. Evidently the maximum speed at which the wading vehicle can travel whilst avoiding these effects depends on factors such as water depth and pitch of the ground surface, but unless the driver is highly experienced in wading there is a significant risk that the maximum speed may be exceeded for a given set of wading conditions. Very low speed wading may be indicated in urban environments to avoid damage due to the vehicle&#39;s wash. 
         [0006]    An aim of the present invention is to at least mitigate the above mentioned problems. by providing better information to the driver. 
       SUMMARY 
       [0007]    Aspects of the invention relate to a vehicle comprising a wading information display, a method and a system as claimed in the appended claims. 
         [0008]    According to another aspect of the present invention for which protection is sought, there is provided a vehicle comprising a processor and a display, the processor being arranged to calculate the maximum wading depth of the vehicle in dependence on one or more vehicle parameters and to display the maximum wading depth on the display. 
         [0009]    In an embodiment, the one or more vehicle parameters comprises the vehicle ride height and/or the vehicle suspension articulation. 
         [0010]    In an embodiment, the vehicle includes a memory, the memory containing a program configured to run on the processor to calculate the maximum wading depth. 
         [0011]    Thus, in embodiments, an accurate display of maximum wading depth can be displayed which accounts for variable height suspension. The driver can then make an informed decision on whether to enter or continue thorough water of a known depth (the depth being known from a roadside gauge, or measured by the driver or onboard vehicle systems). 
         [0012]    The display may comprise a schematic representation of the vehicle such as a side elevation of the vehicle on which is superimposed a line indicative of maximum wading depth. The position of the line on the vehicle may change, for example dynamically, according to a selected vehicle ride height. 
         [0013]    Alternatively, or in addition, the display may be arranged to provide a numerical indication of maximum wading depth, for example 0.5 m, enabling the driver to directly compare the maximum wading depth with the depth of the water as indicated on a roadside gauge. 
         [0014]    In an embodiment of the present invention, the display may be configured to show the current water level through which the vehicle is wading. In one embodiment the water level is displayed in increments which decrease as the wading depth approaches the maximum wading depth. 
         [0015]    Wading depth can be provided to a vehicle control unit from any suitably enabled sensor, or by reference to topographical data and information about vehicle position, for example from GPS. 
         [0016]    The decrease in increment size means that the display will provide increasingly accurate readings to the driver as the maximum level is approached. This is beneficial because the water level is far more critical as it approaches the permitted maximum. Displaying larger increments at lower depth levels prevents the display causing an unnecessary distraction with frequent non-critical updates, according to the refresh rate of the system. 
         [0017]    The information may also be configured to advise the driver of the activation of relevant driving aids such as adjustment of ride height to a maximum, or activation of an off-road mode. It may also offer advice in message form, such as checking that the water exit is clear. 
         [0018]    In one embodiment both maximum wading depth and real time wading depth are simultaneously displayed, for example by reference to a vehicle elevation. The elevation may be front/rear and/or from the side, and driver selectable or simultaneous. 
         [0019]    Optionally, current water level is indicated by a colour wash. The vehicle may include a vehicle inclination sensor, the display showing the elevation at a real-time inclination with respect to the line indicative of maximum wading depth. Optionally, the display is adapted to indicate vehicle inclination in pitch and roll. 
         [0020]    The display may include one of a side elevation and an end elevation of a vehicle. Optionally, the end elevation displayed is the lower end; the side elevation displayed may be the lower side. 
         [0021]    In some embodiments the display includes both a side elevation and an end elevation. 
         [0022]    The maximum wading depth may be adjusted depending on the movement and/or orientation of the vehicle. For example, when travelling forward the maximum depth may be the height of the engine intake. When travelling rearwardly at a negative inclination (e.g. down a slipway) the maximum depth may be the bottom of the tailgate glazing. 
         [0023]    The display may for example show an elevation of the vehicle at the real time pitch or roll angle, with superimposed lines or colour washes indicative of maximum wading depth, and actual wading depth. 
         [0024]    In an embodiment of the present invention, the memory contains a program configured to run on the processor to calculate an advised maximum wading speed of the vehicle from one or more of (i) the water level through which the vehicle is wading, (ii) the pitch of the vehicle and (iii) the angle of the terrain on which the vehicle is travelling, and to display the advised maximum wading speed on the display. 
         [0025]    The provision of an advised maximum wading speed assists the driver in minimising any damage due to excessive speed. 
         [0026]    The advised maximum speed may be displayed in a dedicated display area on the dashboard. Optionally, the advised maximum speed may be displayed or overlaid on the vehicle speedometer. 
         [0027]    According to another aspect of the present invention for which protection is sought there is provided a method of displaying maximum wading depth to a vehicle driver and comprising the steps of calculating the maximum wading depth of the vehicle according to the ride height thereof, and displaying an elevation of a vehicle on which is superimposed said maximum wading depth. 
         [0028]    By “elevation” herein is meant, without limitation, an image, picture or other representation. 
         [0029]    Optionally, the method includes the step of simultaneously displaying on said elevation the actual wading depth of the vehicle according to information from one or more wading sensors. 
         [0030]    The method may further include the step of simultaneously displaying on said elevation an advisory speed for the vehicle, said speed being determined according to the wading depth indicated by a wading depth sensor. 
         [0031]    According to still another aspect of the present invention for which protection is sought there is provided a system for a vehicle comprising a display, a memory, and a processor, the memory containing a program configured to run on the processor to calculate the maximum wading depth of the vehicle from the vehicle ride height, and to display the maximum wading depth on the display. 
         [0032]    According to a further aspect of the present invention for which protection is sought there is provided a computer program stored on a memory device for execution on a processor, the program comprising: calculating the maximum wading depth of a vehicle according to the ride height thereof; and displaying to a driver of the vehicle an image of the vehicle on which is superimposed said maximum wading depth. 
         [0033]    In embodiments of the invention the method includes the step of adjusting the advisory speed according to the inclination of the vehicle indicated by an inclination sensor thereof. 
         [0034]    Within the scope of this application it is envisaged that the various aspects, embodiments, examples, features and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings may be taken independently or in any combination thereof. For example, features described in connection with one embodiment are applicable to all embodiments unless there is incompatibility of features. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0035]    Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying Figures in which: 
           [0036]      FIG. 1  is a schematic side view of a wading off-road vehicle according to embodiments of the present invention; 
           [0037]      FIG. 2  is a side view of the vehicle of  FIG. 1  wading with a first suspension ride height; 
           [0038]      FIG. 3  is a side view of the vehicle of  FIG. 1  wading with a second suspension ride height; 
           [0039]      FIG. 4  is a flow chart of a method according to the an embodiment of the invention; 
           [0040]      FIG. 4   a  is a view of a wading display of the vehicle of  FIG. 1 ; 
           [0041]      FIG. 5  is a view of a wading display according to an alternative embodiment of the invention; 
           [0042]      FIGS. 6   a  to  6   d  are views of the wading display of  FIG. 4   a  in a plurality of states of depth in accordance with the another embodiment of the invention; 
           [0043]      FIG. 7  is a flow chart of a method of calculating an advised maximum speed, in accordance with still another embodiment of the invention; 
           [0044]      FIGS. 8   a  and  8   b  are alternative views of a display in accordance with a further embodiment the invention; and 
           [0045]      FIGS. 9-25  illustrate display formats for a driver display according to embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0046]    Referring to  FIG. 1 , a vehicle  100  comprises a body  102 , a left front wheel  104  and a left rear wheel  106 . The wheels  104 ,  106  (and their counterparts on the right hand side of the vehicle  100 ) are connected to the body  102  via a suspension (not shown). Each of the wheels  104 ,  106  comprises a tyre. 
         [0047]    The wheels  104 ,  106  can move relative to the body  102  to define a ride height R between the lowermost point of the tyres (where they contact the ground) and the lowermost point on the body. The ride height R varies with suspension travel and may be varied by the driver (for example to move from an on-road mode when R is small to an off-road mode when R is large). 
         [0048]    The body  102  comprises a windscreen  108  and a bonnet (or hood)  110  covering an engine bay. On the body  102  between the windscreen  108  and the bonnet  110  there is defined and engine intake orifice  112 . The orifice  112  is connected to an air filter and intake manifold of the engine (not shown). The intake orifice  112  is positioned at a height H from the lowermost part of the body  102 . 
         [0049]    The vehicle  100  is shown wading through water  120  at a water depth D from a ground level  130 . The water depth D should be distinguished from the water level represented by L which is the level of the water  120  above the lowermost point on the body  102 . 
         [0050]    It will be noted that although D can be measured (by a roadside gauge or a measuring stick); the distance L is generally unknown (as R can vary). 
         [0051]    Turning to  FIGS. 2 and 3 , the vehicle  100  is shown having a first ride height R 1  in  FIG. 2  and a second, larger, ride height R 2  in  FIG. 3 . Referring to  FIG. 1 , the maximum depth of water  120  until the intake orifice  112  becomes wet is Dmax 1 =R 1 +H. In  FIG. 2  it is Dmax 2 =R 2 +H. 
         [0052]    The vehicle  100  comprises an onboard ride height sensor (not shown) of known type. Turning to  FIG. 4 , a sequence of events according to an embodiment of the invention is shown. At step  1000  the vehicle ride height R is sensed using the known onboard sensors. The ride height R is then added to the known height H of the air intake orifice  112  relative to the bottom of the vehicle  100 . This represents a safe maximum depth Dmax which is communicated to, and displayed on a driver information display at step  1012 . A display  1020  according to an embodiment of the invention is shown in  FIG. 4   a . The driver can then use a measured depth D of water  120  (either by gauge or onboard depth measurement) to decide whether to proceed. 
         [0053]    In an alternative embodiment there is provided a display  1500 , as illustrated in  FIG. 5 , in which the maximum wading depth Dmax is shown, as well as the current measured wading depth D (as measured by an on board water level sensor, e.g. a capacitive, resistive or hydrostatic sensor). Optionally, the display may also show the inclination of the vehicle  100  as measured by onboard tilt sensors. The driver then has an accurate depiction of the water level L at all positions on the vehicle  100 . The actual wading depth D may be displayed alone. 
         [0054]    Turning to  FIGS. 6   a  to  6   d , a driver information display  1020  is shown in varying states. The display  1020  is connected to a computer memory having software configured to control the display output when run on an associated processor. The software controls the display  1020  by showing the wading depth D at a series of discrete levels. Referring to  FIG. 6   a , 50 percent depth is shown, 75 percent in  FIG. 6   b , 80 percent in  FIG. 6   c  and 90 percent in  FIG. 6   d . As will be noted, the increment between each level becomes smaller towards 100 percent. In this example, the display is configured to have nine discrete states-25, 50 ( FIG. 6   a ), 75 ( FIG. 6   b ), 80 ( FIG. 6   c ), 85 ( FIG. 6   d ), 90, 95, 97.5 and 100 percent. Increments of 25 percent are suitable at low levels (the water level L is of little concern) decreasing to 2.5 percent at higher levels, where water  120  ingress is a risk. 
         [0055]    Turning to  FIG. 7 , there is illustrated another embodiment of the invention which provides a process for calculating an advised maximum wading speed is shown. At step  2000  the water depth D is measured using an onboard water depth measuring system. At step  2002 , the vehicle inclination A is measured using an inclination transducer. At step  2004  depth D and vehicle inclination A are used to determine an advised maximum wading speed Smax which is displayed to the driver at step  2006 . The maximum wading speed Smax is calculated to decrease with increased depth D, and decrease with increased inclination A. In one embodiment, for negative values of inclination A (when the vehicle  100  is travelling uphill), Smax increases as the vehicle  100  leaves the water  120 . 
         [0056]    Referring to  FIGS. 8   a  and  8   b , an advised maximum speed display  2008  is shown. 
         [0057]    The display  2008  is a speedometer displayed on a vehicle multi-function display. A wading indicator  2010  is provided which is illuminated if a wading event is detected. A safe speed range indicator  2012  is also illuminated which highlights a range of speeds (typically 0 to Smax) at which it is safe to travel without causing damage to surrounding objects or the vehicle  100  itself. In  FIG. 8   a  Smax is calculated higher than in  8   b . The indicator  2012  is represented by an arc extending around the speedometer dial, at the tip of the speedometer pointer. 
         [0058]      FIGS. 9 to 25  illustrate embodiments of the invention, in particular there is illustrated a driver display for use in a vehicle  100  when wading. Information for causing the display to appear, to change, and to show information is provided by the sensors which indicate wading and depth of wading D, in particular an ultrasonic sensor such as PDC (parking distance control) sensors. A suitable electronic control system can utilize the outputs of such sensors to control a vehicle display  1020 ,  1500  in a generally well-known manner. 
         [0059]      FIG. 9  shows a representation of a vehicle  10 , a dotted line  11  indicating maximum wading depth; in the illustrated embodiment the maximum wading depth of the vehicle  10  is 0.7 m, and a text display  12  of maximum wading depth. 
         [0060]      FIG. 10  corresponds to  FIG. 9  and also illustrates an icon  13  indicating raised suspension, and a band  14  indicative of actual wading depth. The band  14  may comprise a colour wash. An icon  15 , which may be of any desired form, intuitively demonstrates water level by appearing to float at the indicated level of water. 
         [0061]      FIG. 11  shows a lower wading depth  14  corresponding with a normal height suspension setting, indicated by the icon  16 . 
         [0062]      FIG. 12  shows a vehicle wading at a level indicated by the dotted line  17  with a colour wash below, for example a blue colour wash, and the icon  15 . The line  17  raises and falls in real time according to actual water level. A caution icon  18  is also displayed. 
         [0063]      FIG. 13  illustrates a text indicator showing in text the percentage of maximum permissible depth of wading, in this case 80%, a dotted line at the 80% level, and a dotted line at the level of maximum permissible immersion. 
         [0064]      FIG. 14  shows a vehicle at maximum wading depth with the colour wash and dotted line  17  coinciding with the dotted line  11 . 
         [0065]      FIG. 15  corresponds to  FIG. 13  and shows a vehicle at 90% of maximum wading depth. 
         [0066]      FIG. 16  illustrates a display for the vehicle driver upon detection of water at wading depth, and listing the following: 
         [0067]      FIG. 17  illustrates a driver display with input from a vehicle inclination sensor, again showing actual depth  21 , and maximum permissible depth  22 . A colour wash  23  indicates water. The vehicle representation is shown at the detected inclination. 
         [0068]      FIG. 18  shows a vehicle at a lesser slope than in  FIG. 17 . 
         [0069]      FIG. 19  shows a vehicle reversing into water, for example on a slip way, and utilizing rear facing parking sensors. 
         [0070]      FIG. 20  shows a driver display having the usual speedometer  31  and rev counter  32 . A vehicle representation  33 , corresponding to  FIGS. 1 to 11 , is shown in the centre with a text indication of ‘Wade Aid’  34 . 
         [0071]    Four different terrain response icons  35  are shown below the vehicle representation; the mode which is engaged (left most) being illuminated. 
         [0072]      FIG. 21  shows the terrain response icons also in a separate panel  36 . 
         [0073]      FIG. 22  shows an enlarged portion of the speedometer, an icon  37  indicating descent, and a restricted speed range  38  as an arc around the outside of the speed graduations (in this case extending from 5-35 kph). 
         [0074]      FIG. 23  shows vehicle representations from the side  41  and from one end  42 , indicating water level corresponding to vehicle inclination fore and aft, and side to side. An arrow above the vehicle shows nominal deviation from vertical. The vehicle has greater immersion at the rear, and accordingly a rear vehicle view is illustrated. A front view is shown when the front has greater immersion. A lower strip of icons indicate the state of vehicle functions, and include raised suspension  43  and wading  44 . 
         [0075]      FIG. 24  shows a standard no-wading vehicle driver display, and  FIG. 25  is a variation of  FIG. 20 . 
         [0076]    The present application claims priority to UK patent application numbers filed by the present applicant on 15 Dec. 2010 having the application numbers GB1021268.6, GB1021278.5, GB1021272.8, GB1021297.5, GB1021295.9 and GB1027296.7, the contents of each of which are expressly incorporated by reference in their entirety. 
         [0077]    The present application is related to the PCT applications, and to UK Patent Applications, filed concurrently with the present application, by the applicant of the present application, which are listed below:
       1. PCT application ______ to Thuy-Yung TRAN and Edward HOARE filed 15 Dec. 2011, entitled “System for a Vehicle 1” (agent Ref PWO1110716/JLR10-042WO1);   2. PCT application ______ to Thuy-Yung TRAN and Edward HOARE, filed 15 Dec. 2011, entitled “System for a Vehicle 2” (agent Ref PWO1110717/JLR10-042WO2);   3. PCT application ______ to Thuy-Yung TRAN, Edward HOARE and Nigel CLARKE, filed 15 Dec. 2011, entitled “Vehicle Control System” (agent Ref PWO1110718/JLR10-043WO);   4. PCT application ______ to Thuy-Yung TRAN, Edward HOARE and Nigel CLARKE, filed 15 Dec. 2011, entitled “Wading Depth Estimation” (agent Ref PWO1110719/JLR10-044WO);   5. PCT application ______ to “Thuy-Yung TRAN, Edward HOARE and Nigel CLARKE”, filed 15 Dec. 2011, entitled “Wading Vehicle Depth Measurement Apparatus 1” (agent Ref PWO1110720/JLR10-045WO1”);   6. PCT application ______ to Thuy-Yung IRAN, Edward HOARE and Nigel CLARKE, filed 15 Dec. 2011, entitled “Vehicle Orientation Device and Method” (agent Ref PWO1110721/JLR10-045WO2);   7. PCT application ______ to Thuy-Yung IRAN, Edward HOARE and Nigel CLARKE, filed 15 Dec. 2011, entitled “Wading Vehicle Depth Measurement Apparatus 2” (agent Ref PWO1110722/JLR10-046WO);   8. PCT application ______ to Thuy-Yung IRAN, Edward HOARE, Anthony JONES, Simon THOMSON and Ashutosh TOMAR, filed 15 Dec. 2011, entitled “Wading Vehicle Display 2” (agent Ref PWO1110724/JLR10-047WO2);   9. PCT application ______ to Thuy-Yung IRAN, Edward HOARE, Anthony JONES, Simon THOMSON and Ashutosh TOMAR, filed 15 Dec. 2011, entitled “Wading Vehicle Display 3” (agent Ref PWO1110725/JLR10-047WO3);
 
The contents of the above referenced PCT applications (and corresponding UK applications, filed concurrently and having the same ownership, inventorship and Title as the above listed PCT applications) are hereby expressly incorporated by reference in their entirety into the present application.