FIELD OF THE INVENTION The present invention relates to a method, operator guiding device and computer program product for guiding a vessel operator among obstacles.

BACKGROUND

Vessels such as airplanes and ships have become more and more sophisticated with a lot of different computer systems for handling various functions. Ships are furthermore often controlled via a bridge, from where the navigation takes place.

The bridge of the ship may be surrounded by windows for the crew of the ship to be able to visually observe the environment.

The ships of today are furthermore provided with control computers and user interface screens for visualizing information related to navigation, voyage and ship management systems, where it is possible to provide control of the ship during navigation.

Ship operations on bridges today also require a high degree of attention from the personnel when entering or leaving a harbour as well as at certain operations out at sea such as docking at platforms. In these situations requiring a high degree of

attention, the ship operators may need to visually focus on the operation at hand, such as docking at an object, while at the same time keeping track of

obstacles.

A few techniques have been proposed that are used for assisting ship operators for solving such a problem. WO 2011/151464 does for instance disclose a control system and a joystick that is used for controlling a rudder of a submarine. The control system provides mechanical resistance to the joystick that is used for giving haptic feedback. The control system determines a safety zone and gives haptic feedback if the submarine deviates from the safety zone or is on a collision course with an object. The document more particularly describes that the control system has information about obstacles. The document also describes how the control system determines which rudder positions lead to mechanical damages on the vessel, where these positions are determined based on distances to other vessels and obstacles as well as on winds and currents. JP 56-18713 describes the use of the pitch of a sound to indicate a change in direction of a ship. KR 10- 0621221 describes a system that determines the position of an obstacle based on the sounds of the obstacle. However, there is still need for improvement,

especially when assisting a ship operator when high concentration on an activity is important. SUMMARY OF THE INVENTION

The present invention addresses this situation. The invention is therefore directed towards solving the problem of providing an improvement in relation to informing vessel operators about obstacles when high concentration on an activity is important.

This object is according to a first aspect of the invention solved through a method of guiding a vessel operator among obstacles, where a manoeuvring position is provided on a bridge of a vessel, the vessel comprising a vessel steering unit and having a vessel position and a reference manoeuvring direction, the method being performed by an operator guiding device and comprising the steps of: obtaining obstacle proximity data of at least one obstacle at an obstacle position relating to the vessel position, the obstacle proximity data at least comprising the angle between the obstacle position and the reference manoeuvring direction, determining a presentation position based on the obstacle proximity data, the presentation position being provided at an angle to the reference

manoeuvring direction in relation to the manoeuvring position, which angle corresponds to the angle between the reference manoeuvring direction and the obstacle position, and presenting the obstacle through generating sound appearing to come from the presentation position. This object is according to a second aspect of the invention solved through an operator guiding device for guiding a vessel operator among obstacles, the operator guiding device being provided for a bridge of a vessel, the bridge having a manoeuvring position and the vessel having a reference manoeuvring direction and a vessel position, the operator guiding device comprising a vessel steering unit, a group of loudspeakers on the bridge and a navigation control computer, the

navigation control computer being configured to: obtain obstacle proximity data of at least one obstacle at an obstacle position relating to the vessel position, the obstacle proximity data at least comprising the angle between the obstacle position and the reference manoeuvring direction, determine a presentation position based on the obstacle proximity data, the presentation position being provided at an angle to the reference

manoeuvring direction in relation to the manoeuvring position, which angle corresponds to the angle between the reference manoeuvring direction and the obstacle position, and present the obstacle through generating sound and controlling the group of loudspeakers to make the sound appear to come from the presentation position.

This object is according to a third aspect of the invention achieved through a computer program product for guiding a vessel operator among obstacles, where a manoeuvring position is provided on a bridge of a vessel, the vessel comprising a vessel steering unit and having a vessel position and a reference

manoeuvring direction, the computer program product being provided on a data carrier comprising computer program code configured to cause a navigation control computer to, when the computer program code is loaded into the navigation control computer obtain obstacle proximity data of at least one obstacle at an obstacle position relating to the vessel position, the obstacle proximity data at least comprising the angle between the obstacle position and the reference manoeuvring direction, determine a presentation position based on the obstacle proximity data, the presentation position being provided at an angle to the reference

manoeuvring direction in relation to the manoeuvring position, which angle corresponds to the angle between the reference manoeuvring direction and the obstacle position, and present the obstacle through generating sound and control a group of loudspeakers to make the sound appear to come from the presentation position.

The present invention has a number of advantages. It allows a vessel operator to know the location of obstacles without having to look at them, which simplifies operator concentration on important tasks. This increases safety as a vessel operator is better informed where the vessel is allowed to move in order to avoid obstacles. It also allows the operator to receive feedback on his or her activities, which improves the situation awareness of the operator. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will in the following be

described with reference being made to the accompanying drawings, where

Fig. 1 schematically shows a vessel in the form of a ship having a bridge,

Fig. 2 schematically shows the bridge comprising an operator station from which the vessel may be

navigated,

Fig. 3 schematically shows a computerized control system controlling various operations of the ship, Fig. 4 shows a block schematic of an operator guiding device according to the invention,

Fig. 5 shows a flow chart of a number of method steps being performed in a method of guiding a ship operator, Fig. 6 shows an exemplifying obstacle provided at an obstacle position in relation to a vessel position, Fig. 7 shows a first exemplifying way of determining a presentation position for the obstacle position in fig. 6,

Fig. 8 shows a second exemplifying way of determining a presentation position for the obstacle position in fig. 6,

Fig. 9 shows two exemplifying obstacles provided at corresponding obstacle positions in relation to a vessel position,

Fig. 10 shows an example of two obstacle presentation positions that can be presented as one combined

obstacle presentation position, and

Fig. 11 schematically shows a data carrier with

computer program code, in the form of a CD-ROM disc, for performing the activities of the navigation control computer .

DETAILED DESCRIPTION OF THE INVENTION

In the following, a detailed description of preferred embodiments of a method, operator guiding device and computer program product for guiding a vessel operator among obstacles will be given.

Fig. 1 schematically shows a vessel exemplified by a ship 10. The exemplifying ship 10 shown in fig. 1 comprises a rudder 11, a propeller 12 and a radar 15. The propeller 12 is connected to motor (not shown) in order to propel the ship forward or backward. On the exemplifying ship there may also be azimuth and tunnel thrusters 14 and 16 in order to provide further control of movement of the vessel. These thrusters may be connected to corresponding thruster motors (not shown) . It should be realized that the above mentioned means of propulsion are mere examples and that other types and/or combinations may be used. In order to handle these entities, the ship 10 is also provided with a bridge 13, where various aspects of the ship 10 can be controlled. The rudder 11, propeller 12, thrusters 14 and 16, engines and radar 15 are examples of entities used in relation to the navigation or steering of the ship 10. On the ship there are furthermore a number of sensors. There is a wind speed sensor 17 and an

obstacle position sensor 18. Radar is furthermore one type of position obtaining unit that may be used, while the obstacle position sensor 18 is another type of position obtaining unit. Fig. 2 schematically shows the bridge 13. The bridge 13 comprises three windows 20, 21 and 22, a first front window 20 facing the bow, a second starboard side window 21 and a third port side window 22. The windows are thus placed on the bridge 13. On the bridge there is also at least one steering unit such as a joystick 26, which is provided at an operator station 24. The operator station, which is provided at a manoeuvring position on the bridge may furthermore be a Dynamic Positioning (DP) station 24. The steering unit may be connected to a navigation control computer (not shown) , which handles the navigation aspects. It should here be realized that the operator station 24 may comprise more units such as displays and keyboards or keypads. It may also comprise a chair in which an operator may sit.

However, these have been omitted in order not to cloud the description of the invention with unnecessary detail. On the bridge 13 there is also a group of at least three loudspeakers, in this case four

loudspeakers 28, 30, 32 and 34. These loudspeakers are placed spaced evenly around the bridge around the manoeuvring position. They may be placed at a height that corresponds to the location of the ears of an operator sitting in above-mentioned chair of the DP station 24. In the example given in fig. 2 the

loudspeakers are provided in four corners of the bridge .

The joystick 26 may be a force feedback joystick provided with an electric motor, which motor may be controlled to provide a resistance to the movement of the joystick in various directions. Fig. 3 shows a block schematic of a simplified control system 36 for controlling the ship. The control system 36 is a computerized control system. The control system 36 includes a number of work stations. In the example given in fig. 3 only one is shown, which is the above-mentioned navigation control computer 50. It should however be realized that there may be several work stations for instance in other areas of the ship as well as bridge computers for other types of purposes.

The navigation control computer 50 is connected to a data bus Bl .

There are furthermore a group of vessel handling computers connected to the bus Bl, which computers are provided for handling various aspects of the vessel, such as navigation and security aspects. These

computers more particularly provide data of different types employed in the navigation of the vessel.

There is here a first control computer 38, a

forecasting computer 40, a tracking computer 42, a chart computer 44, a sensor handling computer 46 and an external indications computer 48. These computers are involved in handling various aspects of the vessel. It should be realized that this is just an example. It is for instance possible that there is only one computer implementing the above described functionality.

The first control computer 38 may be involved with controlling steering of the vessel, for example using the rudder 11, thrusters and the propeller. For this reason this computer 38 is connected to an engine 51 for the propeller, to thruster motors 52 and 53 for the thrusters and to the rudder 11.

The forecasting computer 40 is a computer used for keeping track of the weather. It therefore receives weather forecast data from weather forecast services. The forecast data may comprise weather forecasts such as forecasts of low pressure areas, their movements and their wind speeds. This computer 40 is therefore used for keeping track of weather changes and the movement of weather systems such as the movement of storms. It may also forecast or estimate water currents.

The tracking computer 42 is used for tracking other vessels and is therefore connected to the radar 15 as well as possibly to other position sensors such as the obstacle position sensor 18. This computer 42, which may be part of an Automatic Identification (AIS) system, is thus used for keeping track of mobile objects in the environment.

The chart computer 44 comprises navigation charts of the waters through which the ship is to move. The chart computer 44 therefore keeps track of stationary objects or obstacles in the environment. The chart computer 44 may also comprise route data, i.e. data defining a route that the ship is to take.

The sensor control computer 46 is provided for

receiving sensor data such as position data, speed data and draft data for the vessel. It may also receive sensor measurements like wind strength measurements from the wind strength sensor 17. For this reason the sensor control computer 46 is also connected to the sensors 17. However, also other sensors may be provided such a sensors sensing the condition or health of vital elements of the ship.

Finally the external indications computer 48 is

provided for receiving external indications such as piracy indications and/or International Ship and Port Facility Security (ISPS) security indications.

There may also be a control computer involved in ship management, such as controlling ventilation and lights.

It should be realized that the computers mentioned above are examples of computers that may be provided in the system 36. The invention is in no way limited to the specific computers mentioned above.

Fig 4 schematically shows an operating guiding device 54 according to one version of the invention. The operation guiding device 54 comprises the steering unit 26, the navigation control computer 50 and the group of loudspeakers 28, 30, 32 and 34. The steering unit 26 is connected to the navigation control computer 50 and the speakers 28, 30, 32 and 34 are also connected to the navigation control computer 50. The navigation control computer 50 also implements a DP system which in turn employs the first control computer 38.

The bridge 13 of the ship is surrounded by the windows 20, 21 and 22 for the crew of the ship to be able to visually observe the environment of the ship. The bridge may comprise a main bridge and possibly two wing bridges on the port and starboard sides in order to enable support to be given to the captain or navigator as he or she manoeuvres the ship in a harbour.

User interface screens for visualizing information related to navigation, voyage and ship management systems may also be located around the bridge so that they are visible when a crew member is seated or standing next to a pilot chair/station. A crew member standing at the main bridge, can then also look at the meters to see different values related to velocity, pitch, etc.

Ship operations on bridges today require more attention from the personnel when entering or leaving a harbour compared to when out on the sea. Another situation that may require special attention is when placing a ship close to an object at sea, such as at an oil rig. In this case a ship operator may need to be fully alert and attentive in the navigation of the ship. In all the above-mentioned examples the ship operator may need to operate the ship from the DP station 24.

If for instance the ship 10 is a platform support vessel which approaches or is attached to a platform, like an oil platform, it may need to use the DP system to move or keep the vessel to the right position or change the position. The DP system, which is provided through the navigation control computer 50 with the aid of the first control computer 38, is controlled by the joystick 26 that moves the vessel to correction positions by the help of propulsion and steering means such as thrusters, propellers and rudders.

When the DP operator is using the DP system via the DP station 24, to move the vessel, he or she needs to be aware of different obstacles in the surrounding

environment. Such obstacles can be, for example, other vessels, different kind of lines and gears. If not, he or she might steer the vessel towards the obstacles and in the worst case damage the vessel and the platform. At the same time the operator may need to visually focus on relevant objects, such as the platform in order to perform a docking operation. In that case it may be undesirable to use displays of obstacles, because visual attention is needed elsewhere. The operator may thus only get feedback about the

environment through displays or by looking through windows. Therefore, other feedback methods such as tactile or audio are needed.

There exist several reasons for the need of other ways of informing about obstacles. There may for instance exist a risk of hitting different obstacles during the DP operation as visual contact may be blocked. The situation around the vessel may also change quickly due to the weather or the platform conditions and the DP operator may not be able to form an overall picture of obstacles near-by. The invention is provided for addressing at least some of these issues. A method according to a first embodiment of the

invention will now be described with reference being made also to fig. 5, 6, 7 and 8, where fig. 5 shows a flow chart of a number of method steps being performed in a method of guiding a vessel operator, fig. 6 shows an exemplifying obstacle 72 provided at an obstacle position OP in relation to a vessel position VP, fig. 7 shows a first exemplifying way of determining a

presentation position PP for the obstacle position OP in fig. 6 and fig. 8 shows a second exemplifying way of determining a presentation position PP for the obstacle position OP in fig. 6.

The invention operates on position data about

obstacles. Position data about an obstacle 72 may be obtained via a number of different sensors, such as the radar 15 and obstacle position sensor 18. At the same time the position of the vessel 10 may be considered. This may be done through the position data being related to the vessel position from the start. A radar may for instance provide data of the position of an obstacle 72 in relation to the vessel position. This may also be the case if distance data is obtained from the obstacle position sensor 18. As an alternative it is possible that independent obstacle position data is obtained, i.e. obstacle position data that is not related to the vessel position, and thereafter the distance between the vessel position and obstacle position may be determined. This may be the case when satellite based position systems are used. Such

determinations may be performed in the tracking

computer 42, which may therefore be considered to be a position handling computer. As an alternative it is possible that position data is handled in the sensor control computer 46. The determinations may also be performed in the navigation control computer 50. These latter computers may therefore also be considered to be position handling computers. The navigation control computer 50 therefore receives or obtains position data that relates to the positions of obstacles and when related to the vessel position this data also gives information about the distance between the vessel and the obstacle. Such data is in this case also obstacle proximity data. It can in this way be seen that the navigation control computer 50 obtains obstacle

proximity data of at least one obstacle 72 at an obstacle position OP, which obstacle position OP relates to the vessel position VP, step 56.

The vessel 10 may have a reference manoeuvring

direction RMD, which direction may be a forward

direction of the vessel 10, i.e. in the direction from the centre to the stern of the ship. If the position of the vessel is the vessel position VP, which may be the centre of the ship, and the position of the obstacle is an obstacle position OP, then the distance to the obstacle may be considered to be a vector stretching from the vessel position VP to the obstacle position OP. In this case the obstacle proximity data may comprise the angle a between the distance vector D and the reference manoeuvring direction RMD. This is in one variation of the invention the only obstacle proximity data used. The obstacle proximity data may thus only comprise the angle to the reference manoeuvring

position NMP . However, the distance data may also comprise the length of the distance vector D. Thus, the distance data may also comprise the distance between the obstacle and the vessel position.

Furthermore, the navigation control computer 50 also obtains meteorological data, step 58, which

meteorological data may be weather condition data such as wind strength. It may also or as an alternative comprise water current strength. The wind strength data may be obtained from the wind speed sensor 17 via the sensor handling computer 46. The water current strength may be obtained as water current strength estimations from the forecasting computer 40. The navigation control computer 50 may also obtain health data

concerning the health of vital elements of the ship from the sensor control computer 46

Thereafter the navigation control computer 50 compares the distance D with a distance threshold DTH. It thus compares the distance between the obstacle and the vessel position VP. This comparison may involve

comparing the magnitude of the distance vector D with a distance threshold value. In case the distance is below the threshold, step 60, which may indicate that the vessel is within a critical distance of the obstacle 72, then a first obstacle presentation mode is used to present the obstacle using sound, while if the distance is above the threshold, step 60, which may indicate a mildly critical distance, a second obstacle

presentation mode is used to present the obstacle using tactile means.

In the first obstacle presentation mode, the navigation control computer 50 determines a presentation position PP, step 62. Furthermore, this presentation position PP may be related to the manoeuvring position MP used in the DP station 24. The presentation position PP may be determined via a vector d stretching from the

manoeuvring position MP at an angle that at least is related to the angle of the distance vector D and more particularly the angles can be equal. The navigation control computer thus determines the presentation position PP based on the obstacle proximity data, where the presentation position PP is provided at an angle to the reference manoeuvring direction RMD in relation to the manoeuvring position MP, which angle corresponds to the angle between the reference manoeuvring direction and the obstacle position. The angle of the

presentation position may thereby be obtained as an angle between the reference manoeuvring direction and a line drawn from the manoeuvring position in the

direction towards the presentation position. The presentation distance d may be determined in different ways. In one variation, which is depicted in fig. 7, the presentation distance d is fixed. This means that the presentation position PP is provided on the

perimeter of a circle encircling the manoeuvring position MP, which position is then determined by the angle a between the presentation distance vector d and the reference manoeuvring direction RMD. There may thus be a presentation distance vector d having the angle a and a magnitude of fixed value, where the fixed value magnitude is the radius r of a circle.

In another variation depicted in fig. 8, the magnitude of the presentation vector d is related to the

magnitude of the distance vector D. The magnitude of the presentation vector d may furthermore be

proportional to the magnitude of the distance vector D. This may be obtained through a scaling down of the actual distance to fit in the location of the bridge. The threshold may be used to set an outer perimeter of the presentation distance. Thus, in this case the distance to the obstacle is presented through the distance d between the presentation position PP and the manoeuvring position MP corresponding to the distance D between the vessel position VP and the obstacle

position OP.

When the presentation position PP has been determined in this way, the distance to the obstacle is presented using sound or audio. The navigation control computer then generates audio, step 64, and controls the

loudspeakers 28, 30, 32 and 34 to emit sound that interact for seeming to appear at the presentation position PP. The navigation control computer thus presents the obstacle 72 through generating sound and controlling the group of loudspeakers 28, 30, 32, 34 to make the sound appear at the presentation position PP. In other words, the navigation control computer

controls the group of loudspeakers 28, 30, 32, 34 so that for a person sitting in the operator chair the sound seems to have come from the position PP. The presentation may comprise presenting also the distance to the obstacle using the generated sound. In the situation in fig. 7, it is possible that the audio is also processed for presenting the magnitude of the distance vector. The distance may be presented through variations of the sound. This could for instance be done through presenting the sound as pulses of a sound having a certain frequency. The pulse rate may then increase when the magnitude of the distance vector D decreases. The feedback will thereby indicate the direction of and in some cases also the distance to the possible obstacle to prevent the operator from causing any damage .

When making the sound appear at the presentation position, it is possible that the generated audio waveform is mapped to the presentation position through a transformation employing an impulse response filter. The audio waveform may be sampled and subjected to the filter, which may be a finite impulse response filter ("FIR"), which approximates a head related transfer function (HRTF) . The HRTF may mathematically model the variance in phase and amplitude over frequency for each ear of a user for a sound emanating from the

presentation position. This type of processing, may thus be used for making the sound appear to be coming from the presentation position. The sound may thus seem to an observer or operator at the DP station to come from the presentation position. More details of such processing can for instance be found in WO 2008/106680. It is possible to also present other data via sound. The sound may for instance vary depending on a risk level (e.g. concerning the size and the position) of the obstacle. At the same time the navigation control computer 50 may use the meteorological data in the joystick 26 in the first obstacle presenting mode. It may more

particularly present the meteorological data using haptic feedback in the joystick 26, step 68. The navigation control computer 50 may thus present the meteorological data to the operator through making the joystick 26 give haptic feedback corresponding to this data. This may be made so that steering in the

direction that is opposed to the water current

direction is harder or steering against the wind is harder than steering in these directions. The haptic feedback can thus indicate the weather conditions like water current and wind, i.e. going against the current or wind will provide force feedback on the joystick 26. It may also use the health data so that also problems with the ship, such as a failing thruster will be fed back to the user via the joystick 26. It can also be seen that in this way it is possible to use haptic feedback in order to give the operator information of how hard it is to move the vessel in a certain

direction . At the same time the user inputs via the joystick 26 are collected and provided to the first control

computer 38 for use in controlling the steering of the ship 10. After this has been done the navigation control

computer 50 returns and obtains distance data, step 56, meteorological data, step 58, possibly also health data and compares the distance with the distance threshold, step 60.

In the case of the second obstacle presentation scheme, step 60, the work station presents the distance to the obstacle using haptic feedback in the joystick, step 70. For haptic feedback, the joystick 26 of the

operator station 24 can be programmed to give force feedback to indicate a risky direction. If, for

instance, the vessel 10 is moving towards an obstacle, the joystick may not allow the operator to move in that direction or will give him or her haptic feedback that it is a less desirable direction from a risk

perspective . It is in this way possible to provide two different non-visual obstacle feedback modes. Haptic feedback may be desirable at slightly higher distances, while it may be considered limiting for the operator at close distances .

The invention has a number of further advantages. It introduces a range of ways of giving feedback for the DP operator: It employs haptic information, for instance, by using a force feedback joystick. It uses audio feedback with sounds to indicate the proximity of risky obstacles. It provides weather information with the help of haptic feedback to indicate wind and/or current as well as possibly also ship health.

In this way the invention furthermore increases safety. The DP operator is better informed where the ship is allowed to move in order to avoid obstacles. It also provides the operator with situation awareness. The DP operator is better aware of the risk factors in the environment as he will get appropriate feedback

according to his actions. In some situations there may exist more than one obstacle, such as for instance two obstacles. It is possible that such obstacles are presented using different sounds, for instance sound with different frequencies. However, it is possible that the use of different sounds in this way will only confuse the DP operator. It is because of this possible to provide a sound that represents a combination of the two

obstacles. The principle of this will be described with reference being made to fig. 9 and 10, where fig. 9 shows two exemplifying obstacles provided at

corresponding obstacle positions OPi and OP ₂ in

relation to the vessel position VP and fig. 10 shows an example of how two corresponding presentation positions PPi and PP ₂ can be combined and presented as one combined presentation position PPc-

For a first obstacle 72, the distance Di associated with the obstacle position OPi may be considered to be a vector stretching from the vessel position VP to the obstacle position OPi . The distance data may then comprise the angle a between the distance vector and the reference manoeuvring direction RMD and optionally the magnitude of the distance vector Di . In an

analogous manner, the distance D ₂ between the second object 74 and the vessel position VP associated with the obstacle position OP ₂ may be considered to be a vector stretching from the vessel position VP to the obstacle position OP ₂ . The distance data may then comprise the angle β between the distance vector D ₂ and the reference manoeuvring direction RMD optionally together with the magnitude of the distance vector D ₂ . When determining the presentation position of the obstacles 72 and 74, the navigation control computer 50 therefore combines the distance data of the obstacles for forming a combined presentation position PPc- When determining the presentation position PP _C it is

possible to perform a vector combination. This may be a mean value formation of the vectors. The angles may because of this be combined and in this example the mean value ( + β)/2 of the angles may be obtained. In this way a presentation angle may be obtained which is then used for determining the presentation position PP _C of the combined obstacles. It is possible that only this angle is used together with the above-mentioned fixed distance. However, it is possible to use also the magnitude of a vector that is the result of such processing. If a mean value is used, the magnitude of the resulting vector may be divided by two in order to obtain a presentation magnitude. As an alternative it is possible that the magnitude of the combined vector is obtained as:

1/Dc ² = 1/(D!) ² + 1/(D ₂ ) ² . where D _c is the magnitude of the combined vector, while Di and D2 are the magnitudes of the first and second obstacle vectors, respectively.

The navigation control computer thereafter controls the group of loudspeakers 28, 30, 32, 34 to present a sound representing these combined obstacles at the combined presentation position PPc- It can in this way be seen that it is possible to obtain a combination of obstacles, which combination is presented to the DP operator. Several obstacles can in this way be presented without confusing the DP

operator.

The invention was above described in relation to DP operations. It should be realized that the invention is in no way limited to this type of operation, but can be employed also in other situations. The invention is in a similar manner in no way limited to using two

obstacle presentation modes. It may in fact only comprise the first obstacle presentation mode. The second obstacle presentation mode may thus be omitted. The first obstacle presentation mode can furthermore be provided without using haptic feedback of weather data.

The functionality of the navigation control computer may be provided in the form of computer program code in a program memory. This computer program code performs the functionality of the navigation control computer when being run by a processor of the navigation control computer. This computer program code may also be provided on a data carrier which performs the

functionality of the navigation control computer when being loaded into such a program memory. Fig. 11 schematically shows one such data carrier 76, in the form of a CD-ROM disc, which data carrier carries computer program code 78 for performing the activities of the navigation control computer. It is of course possible with other types of data carriers, such as memory sticks.