SE1250325A1 - Procedures and systems for encouraging more fuel efficient vehicle performance - Google Patents

Abstract

The present invention presents a method and system for encouraging a more fuel efficient driving of a vehicle. According to the present invention, a calculation is performed of how a change of at least one parameter related to a driving of said vehicle affects at least one fuel consumption C for said vehicle. Then a presentation is made of the calculated impact on at least said fuel consumption CfUei •. Fig. 1

Description

l0 15 20 25 30 commonly found in motor vehicles. A goal with cruise control is to achieve a smooth predetermined speed, which is done either by adjusting the engine torque to avoid deceleration, or application of braking action, in the downhills where the vehicle accelerates by its own weight.

A driver of a motor vehicle with cruise control usually chooses a set speed vxi. The set speed vxü is the speed that the driver wants the motor vehicle to maintain. However, the vehicle is not always able to maintain this speed, for example on uphill or downhill slopes. A cruise control then provides an engine system in the vehicle with a reference speed web, where the reference speed vn fi is used to control the engine. The set speed vaï can thus be seen as an input signal to the cruise control, while the reference speed vm fi can be seen as an output signal from the cruise control, which is used to control the engine.

In today's traditional cruise control (CC), the reference speed vn fi is identical to the set speed vaü, which has been set by the user of the system, for example a driver of the vehicle. Today's traditional cruise control thus maintains a constant reference speed, which corresponds to the set speed wet set by the driver.

Today, there are also reference speed regulators, such as the “Look Ahead” cruise control (LACC), which are strategic cruise control that uses knowledge of the road sections ahead, ie knowledge of what the road will look like in the future, to determine the appearance of the reference speed vmf. Here, the reference speed is allowed to differ, within a speed range, from the set speed selected by the driver wet to achieve a more fuel-efficient driving. l0 15 20 25 30 The knowledge of the road section in front can, for example, consist of knowledge of prevailing topography, curvature, traffic situation, road work, traffic intensity and road conditions.

Furthermore, the knowledge can consist of a speed limit for the upcoming road section, as well as a traffic sign adjacent to the road. This knowledge can be obtained, for example, by means of positioning information, such as GPS information (Global Positioning System information), map information and / or topography map information, weather reports, information communicated between different vehicles and information communicated via radio.

For example, a LACC allows the reference speed vn fi to be raised in front of a steep uphill slope to a level which is above the level of the set speed wet, since the motor vehicle is assumed to lose speed on the steep uphill slope due to high train weight relative to the vehicle's engine performance. Similarly, the LACC allows the reference speed weave to be lowered to a level which is below the set speed wet in front of a steep downhill slope, since the motor vehicle is assumed to accelerate on the steep downhill slope due to the high train weight. The idea here is that it is more fuel efficient to take the help of the motor vehicle's acceleration caused by its own weight on the downhill slope than to first accelerate downhill and then brake downhill. In this way, the LACC can reduce fuel consumption while largely maintaining driving time.

Brief description of the invention The speed of the vehicle has a very large effect on how much fuel the vehicle consumes. How the vehicle speed affects fuel consumption depends on a large number of parameters and is essentially unique in each driving situation, as it depends, among other things, on vehicle-specific parameters, such as l0 l5 20 25 load (train weight), engine and driveline, and road-specific parameters, such as road slope and road surface, as well as prevailing circumstances, such as weather and wind conditions. It is therefore difficult for a driver of the vehicle to determine in different driving situations how speed affects fuel consumption, which can lead to decisions being made by the driver which from a fuel economy perspective are incorrect.

In general, it is more fuel efficient to maintain a lower vehicle speed. However, the driver may be reluctant to slow down for several reasons. Drivers often have times to keep, that is, they are often commissioned to deliver their cargo at a certain place and at a certain time. Therefore, it is in the driver's nature to maintain the speed in order to deliver the load on time. During longer journeys, even a higher average speed can mean that the driver can take longer breaks and still have time to deliver on time. In other words, drivers easily see the benefits of keeping up the speed, which leads to an increased average speed. This in turn leads to increased fuel consumption.

It is an object of the present invention to provide a more fuel efficient driving of the vehicle.

This object is achieved by means of the above-mentioned method, according to the characterizing part of claim 1. The object is also achieved by means of the above-mentioned system, according to the characterizing part of claim 24.

The object is also achieved by the above-mentioned computer program and computer program product, which implement the method according to the invention. By utilizing the present invention, an incentive is obtained for a driver to take measures that reduce fuel consumption.

By presenting the driver with information which shows how, for example, a reduction in a speed for the vehicle affects fuel consumption, the driver can make a fact-based decision to reduce the speed, which feels sensible and justified for the driver. In other words, it is easier to convince the driver that a speed reduction is appropriate if he is informed of what the benefit of this reduction will be.

In the past, it has been easy for the driver to estimate the disadvantages for the driver himself of lowering the speed, since experience shows that the driver can relatively easily estimate how much the driving time is extended if the speed is reduced.

However, it has been more difficult for the driver to determine if there are benefits, and if so, which ones, with slowing down.

The present invention will thus lead to reduced fuel consumption, as more drivers will be able to be persuaded to make choices which reduce fuel consumption as a reliable figure on this will be presented to the driver. Thus, the present invention also results in a reduced negative impact on the environment, since less pollutants are released into the environment overall when the present invention is applied.

According to an embodiment of the present invention, both effects on fuel consumption and on driving time are presented, which would be the result if the driver changes at least one parameter related to the driving of the vehicle. In this way, the driver is presented with information of the two parameters he is most interested in, which is why the driver here gets a lot of help in making a wise and fact-based choice. According to one embodiment, the parameter that can be changed by the driver is a speed, such as an actual vehicle speed vx or a set speed vxü, which can be easily influenced by the driver. In this way, a direct effect on fuel consumption can be easily obtained, since the driver can be convinced of the benefits of slowing down.

According to one embodiment, the parameter that can be changed by the driver is a used gear in a gearbox, which can be a manual gearbox or can be an automatic gearbox that is used in a manual mode (a manual mode). When the driver is presented with information that tells what the driver can gain by changing gears, the probability is high that the driver actually performs this shift.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further elucidated below with reference to the accompanying figures, in which like reference numerals are used for like parts, and in which: Figure 1 shows a schematic flow chart of the method of the present invention; Figure 2 shows a schematic flow chart of an embodiment of the present invention. Figure 3 shows a calculation of loss power as a function of vehicle speed, Figure 4 shows a calculation of loss energy as a function of vehicle speed, Figure 5 shows a calculation of diesel consumption as a function of vehicle speed, Figure 6 shows an enlargement of a part of Figure 5, 10 Figure 7 shows a control unit according to the present invention.

Description of Preferred Embodiments Figure 1 shows a schematic flow chart of the method of the present invention.

In a first step 101 of the procedure, it is determined how a change of one or more parameters would affect at least the fuel consumption C fi æl for the current road section.

The determination of how these one or more parameters can be based on a calculation of the fuel consumption, which can for example be calculated based on measurements or on models, which is described in more detail below.

In a second step 102 of the method, a presentation is made of the determined impact the change of the one or more parameters will have for at least the fuel consumption C fi æl for the vehicle. For example, it can be presented to the driver how much the fuel consumption C fi æl would decrease if the driver reduced the speed v by a certain number of km / h.

In this way, the driver can easily see what benefits he would get if, for example, he were to slow down v. Being able to present to the driver information which increases the probability that the driver slows down speed v will lead to an overall slightly reduced average speed, and thus also a slightly reduced fuel consumption C fi æl.

According to an embodiment of the present invention, the calculation in the first step 101 in Figure 1 also includes a calculation of how the change of the at least one parameter affects the driving time T the vehicle needs to travel a predetermined distance L. According to the embodiment, the determined effect on the driving time T for the driver in the second stage 102 together with the presentation of the effect on fuel consumption. For example, information can be presented to the driver here about how much fuel is saved and how much longer the driving time T will be if the driver lowers the speed v for the vehicle. When the driver is presented with both the gain in fuel and the loss in driving time T, the driver here will easily be able to see that there is relatively much to gain for fuel consumption C fi wl if one allows a very small extension of driving time T, which will lead to more decisions which reduces the speed v.

As mentioned above, the at least one or more parameters according to an embodiment of the invention comprise a speed v. Thus, here the determination and presentation of the influence of the fuel consumption is based on at least one speed change. This speed v can be an actual vehicle speed væï, which is the actual speed growth the vehicle is driven with on the road. For example, a profit in fuel consumption the driver could make if he were to slow down slightly, for example by releasing the accelerator pedal slightly, is calculated and presented to the driver.

The speed v can also be a set speed vxm for a cruise control in the vehicle. Here, a reduction in fuel consumption C fi æl can be calculated and presented, which is the result of a decrease in set speed vxü. Combining the already fuel-efficient speed control for a cruise control with the encouragement of speed reduction according to the present invention means that the vehicle is driven very fuel-efficiently.

According to an embodiment of the present invention, it comprises at least one parameter, for which change an impact on fuel consumption is to be calculated and presented, a gearbox for a gearbox in the vehicle. Thus, it is determined here l0 l5 20 25 30 how a change would affect fuel consumption C fi æl. For example, a shift to a higher gear, a so-called upshift, which causes the engine to run at a lower speed, can reduce fuel consumption C fi æl, which can be presented to the driver. In the same way as for changes in speed v, the system can thus determine the effect the changeover has on fuel consumption C fi æl and then present this to the driver.

According to an embodiment of the invention, the effect is presented only if a change of the at least one parameter results in a reduction of the fuel consumption C fi æl and is suitable for carrying out. Here it is determined whether the effect on the fuel consumption C fi æl, which is a result of the change of the at least one parameter, constitutes a reduction in the fuel consumption C fl æl or not. In other words, it is determined whether the impact of the speed change is positive or not from a fuel economy perspective. In addition, it is determined whether or not the changes are suitable for other systems in the vehicle. If the effect of the change on the one or more parameters is negative, or if the changes are not suitable to make, the procedure goes back to calculating how future possible changes in parameters will affect the fuel consumption C fi wl.

If the effect that the change has on the one or more parameters is positive from a fuel economy perspective and if the changes are suitable to make, the procedure proceeds to a presentation of the determined impact the change of the one or more parameters will have for at least fuel consumption C fi æl for the vehicle . In this way, the driver is only given arguments for fuel-efficient changes of parameters, which are also suitable for the vehicle to make.

This further increases the probability of achieving a reduced fuel consumption C fi æl, as the driver is specifically given incentives to make appropriate decisions which reduce the fuel consumption of the vehicle. This embodiment is applicable both to the embodiments for changing the speed v and makes changing the gear. However, it is particularly useful for the embodiment where a gain from performing a shift is to be presented, since certain shifts are not always suitable to perform, as the engine in the vehicle should preferably operate within a certain speed range. For example, a shift can be considered suitable if the vehicle after the shift is able to maintain the speed after the shift. In terms of fuel economy, it could be more efficient to drive in a far too high gear, but this would not be suitable for the engine, as a far too high gear gives a far too low speed for the engine and that the vehicle will lose speed. According to this embodiment, only gears are presented that are both fuel-efficient and suitable for the vehicle's other systems.

Figure 2 schematically shows an embodiment of the invention, by means of which the system can determine what information is to be presented to the driver of the vehicle. In a first step 201 of the method according to the embodiment, it is determined, in the manner described above, how a change of one or more parameters affects the fuel consumption C fi æl.

The second 202, third 203 and fourth 204 steps of the method have been exemplified in Figure 2 for the case that the change is a speed change. However, those skilled in the art realize that corresponding steps can also be taken if the change consists of a change, which will also be described briefly during each step.

In the second step 202 of the method, it is determined whether the change in speed v constitutes an increase in speed v or a decrease in speed v. If the change is an increase, the method proceeds to the third step 203, in which the effect of the speed increase on fuel consumption is presented to the driver. Here, therefore, the time gain the driver would achieve by means of the speed increase is not presented in order to avoid that the driver would only get eyes for this possible time gain.

If the change is a reduction, the process proceeds to the fourth step 204, in which the effect of the reduction in speed on both fuel consumption and driving time T is presented to the driver. Here the driver sees that the loss in driving time T is negligible in relation to the gain in fuel consumption C fi æl and hopefully chooses to reduce the speed v.

According to one embodiment, the third 203 and fourth 204 steps are presented simultaneously. Thus, the driver here can directly see both what an increase or decrease of the speed results in.

Figure 2 has been exemplified for the embodiment where a change of the parameter speed v is used. However, the corresponding method can also be used for other embodiments of the invention, for example for upshift and downshift, respectively. For example, then a downshift may result in a presentation according to the third step 203 of the process, while a downshift may result in a presentation according to the fourth step 204 of the process.

According to one embodiment, the fuel consumption C fi æl in the vehicle can be determined based on measurements made in the vehicle. Here, an algorithm can be developed, which is adapted to previously measured values for fuel consumption C fi æl. Using this algorithm, it can then be determined how a change in one or more parameters, for example l0 l5 20 l2 speed v and / or gear, will affect fuel consumption C fi æl.

According to one embodiment, the fuel consumption C fi æl can also be determined by using a model. This model is related to the vehicle in that it describes a number of losses and how they act on the vehicle.

According to one embodiment, the impact on fuel consumption C fi wl is calculated based on the assumption that the road section in question is substantially flat. An example of a model for vehicle losses is described below. Those skilled in the art will appreciate that the losses of the vehicle can be described in a variety of ways, of which the model set forth below is one such example which is utilized by the embodiment.

If the engine efficiency in the vehicle is assumed to be linear, the total loss power for the vehicle can be written as: Plosses I Pair + Prull + PfricPT + PfrícEng + Pbrake f (e kv ° l) where: _-C _ _vact: Add pair a 'V3 111V' 111V '2 GCI constitutes air resistance; - P¿, = P '”w¿a constitutes rolling resistance; TO V0 _ fxærzv fi ï fl wwd-wmMMd4LW | constitute driveline losses; P fi ícEng I ÄngDragLoss (0) fl ywhee}) 'coflywheel constitutes engine losses; . 1 N fwwæl = (F¿ ”+ I @, + n %% gmna) - utgor motor torque; PT VM,. . .. _ w fl ywheel -í fi l fi naldríve-lgearbax constitutes speed 'wh eel 10 15 20 13 is the force of the air resistance against the vehicle; air - v is the vehicle speed; [ICI - AW, is the vehicle acceleration; - pair is the air density; - C; is the coefficient of air resistance; - Fä 'is the force of the rolling resistance against the vehicle; - HPT is the driveline efficiency; - T e @ a% Mß are the friction losses of the engine; _ rwh ed is the wheel radius; -% mMWe is the gear ratio in the final gear; and z is the gearbox gear ratio (s). gearbox and rolling resistance P 'roll The air resistance P' air can be adapted to prevailing wind conditions and road conditions. The vehicle mass ng fl can be provided by a weight measurement system or a weight estimation system in the vehicle.

If the road section is flat, the road slope d is equal to zero, d = 0, and the braking energy is equal to zero. Figure 3 shows an example of a calculation of what the total loss power Plwsæ looks like if the vehicle is assumed to have a mass of 30 tonnes, have a rear axle gear ratio of 2.71, have a specific 13-liter engine and a Scania GRS905 gearbox. Upshifting takes place here at a speed of 1250 rpm. Figure 3 shows the loss power in kW 301 as a function of the vehicle speed wax when the road section is assumed to be substantially flat and the engine has a substantially constant efficiency.

The assumption that the road section is substantially flat simplifies the calculations considerably and provides a system with low complexity.

As shown in the figure, the total loss power Pkßæs has a curve with a substantially serrated profile. The teeth (notch) in the curve are due to shifting in the vehicle, which affects the total loss effect Plwsæ, for example by the total loss effect Pmsæs decreases immediately after a shift to a higher gear is made and then start to rise again with increasing vehicle speed. . For an automatic shifting system, shifting takes place at predetermined engine speeds and / or at predetermined speeds, giving the curve its serrated profile.

An interesting quantity when fuel consumption is analyzed is the loss energy per distance traveled, which can also be seen as consumed fuel per distance. The total loss power Phßæs can be converted to the magnitude loss energy per 100 km by: E / wøkm-P ï losses _ losses (eq. 2) GCI Figure 4 shows loss energy per 100 km 401 as a function of vehicle speed wax for the example in figure 3. As As can be seen from Figure 4, the loss energy per section is relatively large at low speeds (up to 20 km / h), relatively low at medium-high speeds (20-80 km / h) and then slowly rising at high speeds. Here, too, the curve gets notches / teeth when changing gears.

To convert the quantity of energy loss per section to fuel consumption per section, the following relationships can be used: 10 15 20 25 15 than engine '(e kv ° 3) where nm fl æ is the engine efficiency (here approximated as constant); 1H¿d is the energy content of the fuel [Y / L].

For diesel the connection applies: fà fi an ~ _šÃ¶Ln045_ _ ~ (k. 4) Hdíesel engine. 106 e V Cfuez [L] Figure 5 shows diesel consumption per 100 km 501 as a function of vehicle speed vm for the example shown in Figures 3 and 4.

The diesel consumption function per section 501 shown in Figure 5 can very easily be used to determine how a change in vehicle speed wax would affect fuel consumption, by following the curve for diesel consumption per section 501 along an increasing and decreasing vehicle speed, respectively. This is exemplified by arrows 503, 504 for increasing or decreasing the vehicle speed growing from a current speed 502. A simple reading of the curve for diesel consumption per section 501 shows here that the increase 503 of the speed will give an increase in diesel consumption by about 2 liters per 100 km. Correspondingly, it can easily be read that the 504 reduction in speed will reduce diesel consumption by about 2 liters per 100 km. According to the present invention, this information can be given to the driver when the vehicle is driven at the current speed 502. Figure 5 also shows a dotted line curve 510 for a gear A, for example a tenth gear, a dotted curve 511 for a gear B, for example an eleventh gear, and a dashed curve 512 for a gear C, for example a twelfth gear, for the gearbox.

The curves 510, 511, 512 for the tenth, eleventh and twelfth gears can be used in manual shifting to determine what effect a shift has on fuel consumption. If the vehicle has a current speed 507 on an eleventh gear, an upshift 508 to the twelfth gear in the figure can be easily read reducing fuel consumption by about 2 liters per 100 km. A downshift 509 to the tenth gear increases fuel consumption by about 3 liters per 100 km.

Thus, the function for diesel consumption per section 501 can be used to determine how a change in the vehicle speed wax and / or a change affects fuel consumption. This impact can then be presented to the driver so that the driver can make a decision that is fuel-efficient.

If the function for diesel consumption per section 501 is studied in more detail, it can be seen that curve 501 is relatively flat for medium-high speeds (30-70 km / h). Since the curve in this flat area is also serrated due to shifting, in certain situations this special curve shape can be used for an intelligent control of speed and / or shifting.

This is shown in more detail in Figure 6, in which curve 601 which is an enlargement of the curve for diesel consumption per distance 501 in Figure 5 for its relatively flat area. The horizontal line 606 has been inserted here in the figure to illustrate how the function of diesel consumption per distance 601 can be used to optimize vehicle speed wax and / or change with respect to fuel consumption. Curve 601 intersects line 606 10 15 20 25 30 17 at five locations in Figure 6. At these intersections, the vehicle has the same fuel consumption, even though the vehicle speed wax is different for the five intersections. It can therefore be understood that an increase in vehicle speed grows in some cases leads to an unchanged, or even reduced fuel consumption. For example, the vehicle speed can be increased to the last intersection point between curve 601 with line 606, whereby a speed of about 62 km / h can be maintained at the expense of the same fuel consumption as for vehicle speed væï at the first intersection point between curve 601 and line 606, i.e. about 43 km / h. Through an intelligent choice of vehicle speed, a higher vehicle speed can thus be kept "free", ie without increased fuel consumption.

In some situations, even an intelligent choice of vehicle speed can lower fuel consumption. For example, this applies to the current vehicle speed 602 in Figure 6, where a small increase 603 of the speed will reduce diesel consumption by about 2 liters per 100 km at point 605. This is because this small increase causes the engine speed to reach speed (1250 rpm) at which the gearbox shifts up from the tenth to the eleventh gear, which reduces fuel consumption as consumption goes past the top of the ignition 604, wanders 603 down along the tooth, and reaches a lower level at the bottom 605 of the ignition . A prerequisite for maintaining fuel consumption at a lower level is that the vehicle speed is then controlled so that it does not increase too much.

The knowledge of diesel consumption per distance can thus be used to find situations where both increased speed and reduced fuel consumption can be obtained at the same time, which is obviously very advantageous. When such a situation is discovered, it is presented according to the invention to the driver, so that the driver can take advantage of this very favorable opportunity.

As described in connection with Figure 5, the function for diesel consumption per distance 601 shown in magnification in Figure 6 can be used to determine how a change in vehicle speed would affect fuel consumption.

Arrows 613, 614 illustrate an increase and a decrease respectively in the vehicle speed wax from a current speed 612. A simple reading of the curve for diesel consumption per distance 601 shows here that the increase 613 of the speed will give an increase in diesel consumption by about 2 liters per 100 km . Correspondingly, it can be easily read that the reduction 614 of the speed will result in a reduction of diesel consumption by about 2 liters per 100 km. According to the present invention, this information should be presented to the driver when the vehicle is driven at the current speed 612.

According to an embodiment of the invention, the efficiency of the engine is also taken into account in the calculation of diesel consumption per distance. This provides a more accurate function for diesel consumption per distance.

According to this embodiment, a so-called engine shell can be used to determine diesel consumption per distance, which is a mapping of the engine's efficiency as a function of speed and torque. When the engine shell is used, diesel consumption per distance can be determined directly based on engine torque Thwhd and engine speed w fl wkd.

It has been described above how the road section is assumed to be flat in the calculations of fuel consumption per distance, which is often a suitable and non-complex approximation of the conditions if the system lacks information on what the road section really looks like. If there is knowledge of what the road looks like in front of the vehicle, however, this knowledge according to an embodiment of the invention can be used to make the calculations of fuel consumption per distance more accurate.

Knowledge of leading road sections may include topographic information, which may be provided to the system in a variety of ways, for example by utilizing a positioning device, such as a receiver for GPS (Global Positioning System), and by using a device including map information, such as digital maps with topographic information. Topography information can also be measured in the vehicle, for example with a device that determines a road slope d for a road section the vehicle is on.

The system can also be provided with information from a navigation system to obtain knowledge about which road the driver of the vehicle plans to take in the future.

If the system according to the invention has access to this knowledge of the road section in front, a very accurate estimate can be made of the fuel consumption per section, since up and / or downhills in the road section can then be taken into account, which affect the fuel consumption C fi æl. Especially for hilly roads, this embodiment of the invention gives very reliable calculations of the fuel consumption C fi æb The presentation of the calculated impact a parameter, such as a vehicle speed or a gear, has on the fuel consumption C fi æl can be done in a large number of ways and with a large number of illustrative types. For example, one or more of at least one character, at least one number, at least one letter, at least one symbol, at least one pattern, at least one figure, at least one stack, at least one color, at least one brightness, and at least one animation is used to present the impact to the driver of the vehicle.

The presentation can take place by means of a driver interface in the cab, which is suitably positioned so that it can be easily viewed by the driver. For example, the driver interface may be located adjacent to or in the same driver interface as a display of the actual vehicle speed wax, or of the set speed wet for the cruise control. Thus, the driver interface can be located close to, or integrated, with other instrumentation that presents different types of speed.

The presentation can also be activated and deactivated at different times, for example based on whether the possibility of reduction in fuel consumption C fl æl exceeds a fuel consumption threshold or not, so that activation takes place if there is much to be gained from urging the driver to act. The presentation can also be activated when the driver changes the actual vehicle speed wax or the set speed vxü for the cruise control, where the activation according to an embodiment may also require that the possibility of reduction in fuel consumption C fi æl exceeds a fuel consumption threshold. The presentation can also be activated if the vehicle turns into a new road.

According to an embodiment of the present invention, the presentation comprises a change in speed v, which may correspond to an actual vehicle speed wax, or a set speed wax, and which change in fuel consumption C fi æ¿pmm® would result from this change in speed v.

This is shown for a non-limiting example in Table 1. In this example, the actual speed is 80 km / h and the vehicle is running in twelfth gear. As will be appreciated, a corresponding set of wax set tables can also be made.

An increase in the actual vehicle speed growing to 85 km / h would here give an increased fuel consumption C fi æ¿pmm% of 1.5 liters per 100 km. A reduction in the actual vehicle speed growing to 75 km / h, on the other hand, would result in a reduced fuel consumption C fi æk fl wm fi of 1.7 liters per 100 km. The actual vehicle speed wax 80 km / h is already displayed in today's vehicles. According to the embodiment, one or more of the other columns in Table 1 would also be presented to the driver here. vaa = 80km / h vactwskm / h -) vacg-skm / h -) cfuelñchange = + 1. 5 i / i o okm cfuelñchange = - 1. 7 i / 1 o okm Table 1 According to an embodiment of the invention, the presentation also indicates a change in driving time, which the change of the parameter, for example the actual vehicle speed vaü, gives. Table 2 shows the example in Table 1 for this embodiment. Table 2 shows that an increase in the actual vehicle speed væï to 85 km / h here would result in an increased fuel consumption C fi æ¿; m @ W of 1.5 liters per 100 km and at the same time a reduction of the driving time T by 4 minutes per 100 km. A reduction of the actual vehicle speed wax to 75 km / h would result in a reduced fuel consumption C fi æ¿ @ wm% by 1.7 liters per 100 km and at the same time an increase in driving time T by 5 minutes per 100 km. The actual vehicle speed wax 80 km / h is already displayed in today's vehicles. According to the embodiment, one or more of the other columns in Table 2 would also be presented to the driver here. In this way, the driver l0 l5 20 25 22 receives a more complete decision basis for his decision regarding the actual vehicle speed wet.

VQCtI8Okm / h vactl + 5kmlh à Vactz-Eškm / h à C fi æ¿pmmæ = + l.5 l / lOOkm C fi æ¿pmmæ = -1.7 l / lOOkm Och Och T = -4 min / lOOkm T = + 5 min / lOO km T fl mll2 According to an embodiment of the invention, the information is presented in Tables 1 and 2, i.e. profit / loss fuel consumption C fi æl, and profit / loss fuel consumption C fi æl and profit loss in driving time T for an upshift or downshift, which is particularly useful in vehicles with manual exchange.

As mentioned above, the information concerning the impact on fuel consumption C fi wl, and where applicable also the impact on driving time T, can be presented in other ways than with figures. For example, different colors can represent different types of influence, such as green color for improvement and red color for deterioration of fuel consumption C fi æl and / or driving time T. Also different brightness can indicate the size of improvements / deteriorations, for example by a green color shining brighter and brighter the greater the profit made for fuel consumption C fi æl. These colors can be provided, for example, by means of one or more diodes, a monitor, or the like. Menu systems on a monitor can also be used to convey the effect on fuel consumption C fi æl, and also the effect on driving time T. For example, an information box on the screen here can be arranged to appear, scroll down, or the like, when the driver turns on the cruise control, when the driver changes the set speed for the cruise control, or manually changes the vehicle speed increases, if a change can yield large gains, when the vehicle turns off on a new road, and at any other suitable time when the driver should be informed of possible gains to do.

According to an embodiment of the invention, the presentation depends on a driving mode currently applied in the vehicle. For example, if an economical driving mode is applied, the presentation can focus on changes that result in reduced fuel consumption C fi æl, for example by only showing a possible reduction in fuel consumption C fi æl for a speed reduction, and not how much this reduction prolongs driving time T. In a driving mode for more powerful vehicles, so-called "power mode", the focus in the presentation can instead be on the possibility of reduced driving time T, so reduced driving time T must be clearly stated in the presentation.

Those skilled in the art will recognize that a method of encouraging a more fuel efficient vehicle performance in accordance with the present invention may additionally be implemented in a computer program, which when executed in a computer causes the computer to perform the method. The computer program usually consists of a computer program product 703 (shown in Figure 7) stored on a digital storage medium, the computer program being included in a computer program readable medium of the computer program product. Said computer readable medium consists of a suitable memory, such as for example: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc .

Figure 7 schematically shows a control unit 700. The control unit 700 comprises a calculation unit 701, which may be constituted by substantially any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or an Application Specific Integrated Circuit (ASIC).

The calculation unit 701 is connected to a memory unit 702 arranged in the control unit 700, which provides the calculation unit 701 e.g. the stored program code and / or the stored data calculation unit 701 is needed to be able to perform calculations. The calculation unit 701 is also arranged to store partial or final results of calculations in the memory unit 702.

Furthermore, the control unit 700 is provided with devices 711, 712, 713, 714 for receiving and transmitting input and output signals, respectively. These input and output signals may contain waveforms, pulses, or other attributes, which of the input signals receiving devices 711, 713 may be detected as information and may be converted into signals which may be processed by the computing unit 701. These signals are then provided to the computing unit 701. The devices 712 , 714 for transmitting output signals are arranged to convert signals obtained from the calculation unit 701 for creating output signals by e.g. modulate the signals, which can be transmitted to other parts of the system to encourage a more fuel efficient vehicle performance.

Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may consist of one or more of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Orientated Systems Transport bus), or any other bus configuration; or by a wireless connection. One skilled in the art will appreciate that the above-mentioned computer may be constituted by the computing unit 701 and that the above-mentioned memory may be constituted by the memory unit 702.

According to one aspect of the present invention, there is also provided a system for encouraging a more fuel efficient operation of a vehicle. The system comprises a calculation unit, which is arranged to calculate how a change of at least one parameter related to a driving of said vehicle affects at least one fuel consumption C fi æl for the vehicle. This calculation unit can also be set up to perform all calculations necessary to perform the above-described embodiments of the invention, for example to also calculate the effect of the change on the driving time T.

The system also comprises a presentation unit, which is arranged to present the calculated effect on at least the fuel consumption C fi æl. This presentation unit can also be set up to present the effect of the change calculated for the embodiments described above, for example how the driving time T is affected by the change.

Those skilled in the art will appreciate that the above system may be modified according to the various embodiments of the method of the invention.

In addition, the invention relates to a motor vehicle, for example a truck or a bus, comprising at least one system for encouraging a more fuel-efficient vehicle operation.

The present invention is not limited to the above-described embodiments of the invention but relates to and encompasses all embodiments within the scope of the appended independent claims.

Claims (24)

10 15 20 25 26 Patent claim A method for encouraging a fuel efficient driving of a vehicle, characterized by: - calculating how a change of at least one parameter related to a driving of said vehicle affects at least one fuel consumption C fi æl for said vehicle; and - presentation of the estimated impact on at least said fuel consumption C fi æl. A method according to claim 1, wherein said calculation comprises a calculation of how said change affects at least one driving time T for a predetermined distance L for said vehicle. A method according to claim 2, wherein said presentation comprises a presentation of the calculated effect on said driving time T. A method according to any one of claims 1-3, wherein said at least one parameter comprises a speed v. A method according to claim 4, wherein said speed v is a speed in the group of: - an actual vehicle speed Vax; and - a set speed vxm for a cruise control in said vehicle. A method according to any one of claims 1-5, wherein said at least one parameter comprises a gearbox for a gearbox. A method according to any one of claims 1-6, wherein said change is unique for each time, road section and vehicle. 10 15 20 25 27 A method according to any one of claims 1-7, wherein said influence of said fuel consumption C fi æl is calculated based on measurements of fuel consumption in said vehicle. A method according to any one of claims 1-7, wherein said influence of said fuel consumption C fi æl is calculated based on at least one model related to said vehicle. A method according to claim 8, wherein said model comprises one or more of the losses in the group of: - an air resistor Pæï; - a rolling resistor Prml; - a driveline resistor Pf fl qyf; - a motor resistor P fi¿ Q¿m; and - a brake resistor Pmam. A method according to any one of claims 1-10, wherein said influence of said fuel consumption C fi ml is calculated based on an efficiency mapping for an engine in said vehicle. A method according to any one of claims 1-11, wherein said calculation of said impact is performed based on an assumption that a road section in front of said vehicle is substantially flat. A method according to any one of claims 1-11, wherein said calculation of said impact is performed based on a knowledge of a road section in front of said vehicle. The method of claim 13, wherein said knowledge comprises topography information for said road section. A method according to claim 14, wherein said information about said topography is provided by at least 28 a device in the group of: - a positioning device; a map information device; and - a device which calculates a road slope d based on at least one measurement made in said vehicle. A method according to any one of claims 1-15, wherein said presentation utilizes at least one type of illustration in the group of: - at least at least at least one character, a number, a letter, a symbol, - at least one pattern, - at least one figure, - at least one bar, - at least one color, - at least one brightness, and - at least one animation. A method according to any one of claims 1-16, wherein said presentation is performed by a driver interface at any of the positions in the group of: - in connection with a presentation of a set speed wet for a cruise control in said vehicle; and - in connection with a presentation of an actual speed v förm for a said vehicle. A method according to any one of claims 1-17, wherein said presentation indicates: - a change in speed v, and - a change in fuel consumption C fi æl which is a result of said change. 10 15 20 25 30 29 A method according to any one of claims 1-18, wherein said presentation indicates: - a change of utilized gear for a gearbox in said vehicle, and - a change in fuel consumption C fi æl which is a result of said change. A method according to any one of claims 18-19, wherein said presentation further indicates: - a change in driving time T which is a result of said change. A method according to any one of claims 18-20, wherein said presentation depends on a selected driving mode for said vehicle. A computer program comprising program code, which when said program code is executed in a computer causes said computer to perform the method according to any one of claims 1-21. A computer program product comprising a computer readable medium and a computer program according to claim 22, wherein said computer program is included in said computer readable medium. A system for encouraging the fuel-efficient operation of a vehicle, characterized by: - a calculation unit, arranged for calculating how a change of at least one parameter related to a driving of said vehicle affects at least one fuel consumption C fi æl for said vehicle; and - a presentation unit, arranged for presentation of the calculated impact on at least said fuel consumption Cfuel -