SE534166C2 - Method and computer program for improving the drivability of a motor vehicle - Google Patents

Abstract

The invention relates to a method for improving the drivability of a motor vehicle (100,110), with a first vehicle condition regarding a starting phase, and a second vehicle condition regarding a driving phase, wherein said motor vehicle comprises an actuator (220) to be used for requesting the vehicle engine speed. The method comprises the step of determining whether the first vehicle condition exists and, on the basis of said first vehicle condition, determining whether a requested engine speed, as a result of operating an actuator (220), exceeds a preset engine speed value (G). If the requested engine speed exceeds said preset engine speed value (G), an output motor speed signal (PS_OUT *) is generated to control the engine speed to prevent said preset regulated engine speed from exceeding said engine speed value (G). The invention also relates to a computer program for improving the driveability of a vehicle, comprising machine-readable program code causing an electronic control unit (200), or another computer connected to the electronic control unit (200), to perform the steps according to the method. Figure 3b for publication.

Description

535 'H55 tendency to slip on the clutch for longer than necessary when changing gears, especially when starting from a standstill. Today, there are methods for overcoming the inconveniences indicated above, by regulating the torque delivered or requested by the driver, ie. reduce the torque delivered or requested by the driver. Nevertheless, these methods are associated with disadvantages such as not providing a fixed engine speed limit.

EP 1718883 describes a control device for avoiding clutch wear due to unnecessarily large pedal path. The device consists of a first, second and third calculation module, where the first calculation module is to be calculated arranged for the necessary engine speed value from the output load of the gearbox and the current change-over gear in accordance with which the engine speed is adjusted for a shift process.

EP 1478544 describes a method and a system for determining an engine speed to be used by a control system for centrifugal clutch when starting a vehicle.

Summary of the invention An object of the invention is to provide a new advantageous way of improving the driveability of a vehicle.

Another object of the invention is to provide a method and a computer program for improving the driveability of a vehicle. An object of the invention in accordance with an aspect of the invention is to provide a method for further improving the drivability of a vehicle. An object of the invention in accordance with an aspect of the invention is to provide an alternative method for improving the drivability of a vehicle during a starting phase.

Another object of the invention is to provide a method and a computer software product for achieving reduced wear on a vehicle coupling.

These objects are achieved by a method for improving the drivability of a vehicle, said method comprising the step according to claim 1.

By performing an engine speed reduction during a starting phase, ie. by processing a signal generated on the basis of an accelerator pedal position, an improved driveability of a vehicle is obtained. In particular, the drivability of the vehicle is increased when starting from a standstill, since a more suitable engine speed is actually requested. The engine speed requested by the driver may therefore differ from the engine speed requested by the vehicle control unit, in the event that the driver requests an engine speed that exceeds a certain permitted engine speed during the starting phase.

It should be noted that the physical pedal position is not limited, but that the method in accordance with one aspect of the invention relates to a limitation of the signal regarding the accelerator pedal position. In other words, the value p is limited if the first state exists. Accordingly, in this way, the required engine speed of the vehicle in accordance with the invention is limited.

The method is easy to implement in future vehicles. Engine speed reduction software can be installed in a control unit in the vehicle during its manufacture. The buyer of the vehicle can be offered the choice to use the stored control function regarding engine speed.

Alternatively, the engine speed reduction software can be installed in a control unit in the vehicle when upgrading the vehicle at a service workshop. In this case, the software is simply downloaded to the vehicle control unit. 10 15 20 25 534 166 the implementation of the innovative method is consequently cheap since no additional sensors or other components are required. The necessary hardware is already in today's vehicles.

The method in a more accordance with the invention provides user-friendly vehicle because less experienced drivers will be able to benefit from a well-functioning support function. An inexperienced driver can be persuaded to select a sufficiently low gear when starting from a standstill.

The method in accordance with the invention advantageously achieves the ability to provide the maximum output torque of the engine. The output torque of the engine may be provided within a range between a suitable minimum value and a suitable maximum torque value for a given engine speed in the vehicle.

The term "start" refers to an initial phase. The term "start" may refer to a phase which includes a period of time from the time when the vehicle is essentially stationary until a certain speed has been reached. The term "start" may refer to a phase including disconnection of the coupling device, loading of gear and renewed engagement of the coupling device. The term “start phase” and the term “start” refer to a phase that begins when a first condition exists and ends when a second condition exists.

Said preset engine speed value may be in the range of 500-1500 rpm. It advantageously covers the möjest possible scenarios.

Said preset engine speed value may be in the range of 650-850 rpm. A relatively low engine speed advantageously reduces wear on the clutch.

Said preset engine speed value may be in the range of 1000-1200 revolutions per minute. This advantageously provides a higher maximum output torque in the event of a high drive resistance. The maximum output torque is significantly higher than in the case of a lower engine speed in the vehicle.

Said first vehicle permit may include: a) The vehicle is stationary and the engine is running at idle speed; b) The vehicle is essentially stationary; c) The vehicle starts moving, in either direction, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h; d) The vehicle is in motion, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h, with the clutch disengaged; or e) The vehicle starts moving, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h, with the clutch disengaged for a predetermined period of time, e.g. 2 seconds.

The method can, in the step of determining in case a requested engine speed / number exceeds a preset engine speed value, generate a request regarding engine speed on the basis of the relative position of the actuator.

This provides a simplified way of maintaining the desired engine speed. At the request of a certain engine speed, which correlates with a certain accelerator pedal position, the engine's output torque can be automatically regulated by means of a regulator.

The actuator may include an accelerator pedal. This provides a simplified way of maintaining the desired engine speed.

The method may further comprise the steps of: - determining whether the second vehicle condition exists; 10 15 20 25 534 166 - on the basis that said other vehicle condition exists, generating an output signal regarding engine speed for regulating the engine speed on the basis of said requested engine speed.

Said other vehicle condition may include: a) The accelerator pedal is in a predetermined position, e.g. in its top position; b) The vehicle's clutch is engaged, ie. engine speed and input rotational frequency are essentially equivalent; c) The vehicle's clutch has been engaged, after a gear change has been made; d) The vehicle is in motion, in either direction, at a speed exceeding a predetermined speed, e.g. exceeding 7 km / h; e) The vehicle is in motion at a speed exceeding a predetermined speed, e.g. exceeding 7 km / h, with the clutch engaged; f) The vehicle starts moving, at a speed exceeding a predetermined speed, e.g. exceeding 7 km / h, with the clutch engaged since a predetermined time period, e.g. 1 second; or g) The clutch pedal is in its uppermost position.

A control unit in the vehicle may include routines for handling different types of gearboxes, and may also include routines for stepwise application of torque after the starting position phase has been deactivated. Consequently, a control unit in the vehicle can be prepared to fit different vehicles equipped with different gearboxes and control systems applicable thereto, e.g. Scania "Opticruise".

The present objects are also achieved with a computer program for improving the driveability of a vehicle, comprising machine readable program code causing an electronic control unit, or another computer connected to the electronic control unit, to perform the step according to claim 10. The preset engine speed value may be in the range 500-1500 rpm. Said preset engine speed value may be in the range of 650-10 15 20 25 534 166 850 rpm. Said preset engine speed value may be in the range of 1000-1200 revolutions per minute.

The computer program may, in the step of determining if a requested engine speed exceeds a preset engine speed value, generate a request for engine speed based on the relative position of the actuator.

The actuator may include an accelerator pedal.

The computer program may further comprise the steps of: - determining whether the second vehicle path condition exists; - on the basis of the existence of said other vehicle permit, generation of an output signal regarding engine speed for regulating the engine speed on the basis of said requested engine speed.

Said first vehicle condition may include: a) The vehicle is stationary relative to a fixed reference point, where the engine is running at idle speed; b) The vehicle is essentially stationary relative to a fixed reference point; c) The vehicle starts moving, in either direction, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h; d) The vehicle is in motion, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h, with the clutch disengaged; or e) The vehicle starts moving, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h, with the clutch disengaged for a predetermined period of time, e.g. 2 seconds.

The objectives are also achieved with a computer, e.g. an embedded electronic control unit or a vehicle external computer, which comprises a storage medium ISS and a computer program for improving the drivability of a motor vehicle in accordance with the invention, and which is stored on the storage medium.

The invention also refers to a vehicle that includes the computer. The vehicle can be a truck or a bus.

An advantageous value of the invention is that a cost-effective solution to the above problems is achieved. The method is simple to implement in dangerous vehicles and it is also easy to modify and upgrade a computer program which includes program code for carrying out the innovative method by means of a communication terminal arranged for communication with a control unit comprising said program code. Yet another advantageous value of the invention is that the method for improving driveability is robust.

The procedure of starting a vehicle from a standstill is improved, especially if the driving resistance is high. The vehicle driver is likely to perceive the engine as being stronger as the engine will have an increased ability to maintain the desired engine speed without the driver having to provide more gas during the clutch activity. The extension will therefore give the vehicle driver increased comfort. As the engine achieves a better ability to maintain the desired engine speed at vehicle starting from a standstill, fewer transients will occur in the driveline.

By using the innovative method, the wear on the coupling device in the driveline will be reduced as a result of the time required for the coupling activity being shortened.

A vehicle driver will probably find it easier to engage the clutch at vehicle start-up, in particular a driver may find it easier to start when the vehicle is heavily loaded when starting uphill, or when starting on loose ground e.g. a gravel road. Additional objects, advantages and innovative features of the present invention will become apparent to those skilled in the art from the following detailed description, as well as from the practice of the invention. Although the inventory is described below, it should be noted that the inventory is not limited to the reported information. Those skilled in the art with access to the knowledge herein will gain insight into further applications, modifications, and embodiments in other areas which fall within the scope of the invention.

Brief Description of the Drawings In order to provide a more complete understanding of the present invention further objects and advantages continue to the examples shown in the accompanying figures: and with this, Figure 1 schematically shows a vehicle in accordance with one aspect of the present invention; Figure 2 schematically shows a subsystem of a vehicle in accordance with an aspect of the present invention; Figure 3a schematically shows a signal processing process in accordance with an aspect of the present invention; Figure 3b schematically shows a signal processing process in accordance with an aspect of the present invention; Figure 3c schematically shows a diagram in accordance with an aspect of the present invention; Figure 4 schematically shows a fate diagram depicting a method for improving the driveability of a motor vehicle in accordance with an aspect of the present invention; and Figure 5 schematically shows an electronic control unit in accordance with an aspect of the present invention. Detailed Description of the Drawings Referring to Figure 1, a side view of a vehicle 100 is shown. The vehicle 100 includes a tractor 110 and a trailer 112. The vehicle 100 may be a heavy vehicle, e.g. a truck or a bus. Alternatively, the vehicle 100 may be a passenger car.

Furthermore, the term "link" refers to a communication link which can be a physical contact, communication line, or a non-physical contact or wireless connection, consisting of a e.g. an optoelectronic e.g. a radio or microwave link.

Referring to Figure 2, a subsystem 299 of the vehicle 100 is shown.

The subsystem 299 includes a driveline arrangement in the vehicle 100.

The motor vehicle 100 depicted in Figure 1 has a schematically illustrated driveline. The driveline has an internal combustion engine 230 which is controlled by an electronic control unit 200. For this purpose, the control unit 200 is depicted), various sensors, signal connected to various actuators (not eg a throttle valve adjusting device, and to eg rotational speed sensor. is connected via a shaft 231, a clutch 235 and a shaft 236 to a gearbox 240. The gearbox 240 is arranged to drive in a well-known manner a number of wheels 245 belonging to the vehicle 100.

The control unit 200 is signal connected to an actuator 220, e.g. and accelerator pedal. In particular, a vehicle driver can set a desired engine speed value for the internal combustion engine 230 by means of the actuator 220. In particular, this invention relates to situations where the vehicle 100 is substantially stationary and where the driver is about to start by accelerating the vehicle by shifting into a first gear. , e.g. the first lowest gear. In accordance with this example, the electronic control unit 200 is arranged to control the internal combustion engine 230, the clutch 235 and the gearbox 240. Nevertheless, a gearbox control unit (not shown) can be provided for communication with the electronic control unit 200 and / or for direct communication with the clutch 235 and the gearbox 240 so as to control the clutch 235 and the gearbox 240.

Here, according to an example, the innovative method is initiated and regulated by means of the electronic control unit 200. According to an example, the electronic control unit 200 is an electronic motor control unit. Alternatively, the innovative method is initiated and controlled by an external computer 210. The external computer 210 can be connected directly to the electronic control unit 200 via a link 215, but can also be connected indirectly to the electronic control unit 200 in a suitable manner, e.g. via the vehicle's internal date measurement. The communication between the external computer and the electronic controller 200 may be partially or completely wireless.

The innovative method can also be initiated and controlled by means of the electronic control unit 200 or with another electronic control unit, e.g. an electronic control unit for the gearbox.

The electronic control unit 200 is arranged for communication with a communication terminal 280 via a link 285. In addition, the external computer 210 is arranged for communication with a communication terminal 280 via a link 286. The communication terminal 280 may be provided with a display and a user interface to provide the user possibility 200.

The communication terminal 280 is arranged for displaying information which is to interact with the electronic control unit relevant to the method of invention, engine speed, e.g. 750 or 1100 rpm. for example maximum With reference to Figure 3a, a schematic representation of a signal processing process is shown. The signal processing process is not provided with a control function regarding engine speed reduction. More specifically, IBS 12 specifically depicts a schematic representation of an engine speed control diagram. It appears from the clock that an input signal regarding motor speed PS__ | N is supplied to a logic unit 310. The logic unit 310 can advantageously be implemented in an electronic control unit in the vehicle or in a computer arranged for regulating functionality in the vehicle. The motor speed signal PS_lN includes information about a desired motor habit / speech value. This desired engine speed value can be generated by using the actuator 220 (shown in Fig. 2). The motor speed signal PS_lN is generated in accordance with an embodiment based on an operating process. The maneuvering process can be performed manually by the vehicle driver. An example of the actuating process may be the use of the actuator 220. In accordance with an embodiment of the present invention, the desired engine speed value is generated based on the position of the accelerator pedal 220.

The position of the accelerator pedal 220 in the vehicle can be defined by an angle α, where the angle α corresponds to an engine speed factor p. The engine speed factor p extends between 0 and 100, i.e. Os p 5100. The highest position of the accelerator pedal 220 corresponds to the engine speed factor value 0. This corresponds to an initial accelerator pedal position, where no accelerator is applied, ie. the driver does not request any torque or additional engine speed beyond idle speed.

The lowest position of the accelerator pedal 220 corresponds to the maximum accelerator pedal position, ie. a situation where the driver requests full power. The input signal regarding engine speed may depend on the angle α or the engine speed factor p.

It can be seen from the figure that an output signal for motor speed PS_OUT is supplied from the logic unit 310. The output signal for motor speed PS_OUT includes information on a desired motor speed value.

Figure 3a depicts a case where no engine speed reduction is performed.

Consequently, the output signal for motor speed PS_OUT is substantially equal to the input signal for motor speed PS_1N, i.e. PS_OUT = PS_lN. Referring to Figure 3b, there is schematically shown a signal processing process provided with a control function for engine speed reduction in accordance with one aspect of the invention. More specifically, a schematic representation of a control diagram regarding engine speed, similar to that depicted with reference to Fig. 3a, is depicted. It can be seen from the figure that an input signal regarding motor speed PS_1N is supplied to a logic unit 320. The logic unit 320 can advantageously be implemented in an electronic control unit in the vehicle or in a computer arranged for regulating functionality in the vehicle. The motor speed signal PS_lN includes information about a desired motor speed value. This desired engine speed value can be generated by using the actuator 220 (shown in Fig. 2). The motor speed signal PS_lN is generated in accordance with an embodiment based on an operating process. The maneuvering process can be performed manually by the vehicle driver. An example of the actuating process may be the use of the actuator 220. In accordance with an embodiment of the present invention, the desired engine speed value is generated on the basis of the position of the accelerator pedal 220.

The position of the accelerator pedal 220 in the vehicle can be denoted by an angle α, where the angle α corresponds to an engine speed factor p. The engine speed factor p extends between 0 and 100, i.e. 0 s p s 100. The highest position of the accelerator pedal 220 corresponds to the engine speed factor value O. This corresponds to the idle or idle speed of an initial vehicle. The lowest position of the accelerator pedal 220 corresponds to the maximum accelerator pedal position, ie. control device does not request torque additional engine speed in addition to accelerator pedal position, ie. a situation where the driver requests full power. The motor signal input signal may depend on the angle α or the motor speed factor p.

Figure 3b depicts a case where engine speed reduction is performed, in accordance with one aspect of the invention. Consequently, the output signal for motor speed PS_OUT * may in some cases differ from the input signal for motor speed PS_1N1, i.e. PS_OUT1 *: PS_IN1, see further detailed description below.

It should be noted that the input signal regarding motor speed PS_IN is substantially equivalent in the cases depicted with reference to Fig. 3a and Fig. 3b.

Here below, an engine speed function N (p) is denoted, which is a function which returns an engine speed value N, based on the accelerator pedal position, i.e. N (P) = SEK> + m Where: p: is a variable indicating a position regarding the accelerator pedal 220 as depicted with reference to Figs. 2, 3a and 3b. The variable p has a value in the range [0, 100] depending on the position of the pedal; k: is a first predetermined constant; m: is a second predetermined constant.

In accordance with this example, N (p) is a linear function. However, one skilled in the art will recognize that other types of functions may be applied, e.g. logarithmic, exponential or multi-polynomial functions.

In accordance with this example, k is given a value in the range [400, 5001, e.g. 430 or 430.9. IBS 15 In accordance with this example, m is given a value in the range [18, 23], e.g. 20 or 20.7.

It should be noted that the constants k and m can be given arbitrary values, ie. any suitable value can be used for k and m, even values outside the above range. For example, k can be given a value in the range [300, 6001, and m can be given a value in the range [15, 25]. Constant themes k and m can be given values in accordance with the characteristics of the vehicle in question, e.g. engine type or engine size. In accordance with one aspect of the invention, the logic unit 320 is arranged to reduce the engine speed in the starting phase of the vehicle. l according to an example N (p) = 430 + 20.7p, 0 s p s X, where X is a preset value.

N (p) = G, p> X, where G is a preset value.

According to this embodiment, X is a constant in the range [10, 201, e.g. 15.8. In accordance with this embodiment, G is a constant in the range [700, 800], e.g. 750.

It should be noted that the constants X and G can be given arbitrary values, ie. any suitable value can be used for X and G, even values outside the above range. For example, X can be given a value in the range [15, 25] or [14, 17], and G can be given a value in the range [650, 850] or [730, 7801. The constants X and G can be given values according to the characteristics of the vehicle in question, e.g. engine type or engine size.

That is, if the requested engine speed (as indicated by the PS_lN engine speed input signal) is higher than the preset value during the vehicle's start phase, the maximum permissible engine speed is provided. Consequently, a driver can not achieve a higher engine speed than the maximum permitted engine speed (G) during a phase where a first condition exists (eg when the vehicle is stationary). However, the driver can achieve the required engine speed during a phase where a second condition exists (eg when the vehicle has reached a predetermined speed or when the clutch has been engaged). The engine speed can consequently be regulated in an innovative way during vehicle start-up, so that wear on the vehicle clutch is reduced.

The logic unit 310 and the logic unit 320 may be implemented in the form of software in the control unit 200. Alternatively, the logic unit 310 and the logic unit 320 may be implemented in the control unit 200 in the form of a hardware circuit.

As a comparative example, according to one aspect of the invention, the logic unit 310, which is not arranged to reduce the motor speed in the starting phase, is arranged to output an output signal for motor speed PS_OUT on the basis of an input input signal for motor speed PS_IN. In accordance with an example, the engine speed function N (p), which is stored in the logic unit 310, and which is a function which returns an engine speed value N, based on the accelerator pedal position, can be expressed: N (p) = 430 + 20.7p, 0 _ <. P S100 Both outputs regarding engine speed PS_OUT and PS_OUT * include information determined by the engine speed function N (p), namely a calculated engine speed value, which is used to control the vehicle's engine.

Referring to Figure 3c, a diagram is shown in which the stored values of the engine torque and speed are schematically depicted. Maximum engine torque T is plotted against the EGR engine speed, and the curve is denoted C. 10 15 20 25 534 156 17 Operating areas are plotted where a first motor speed control function for a first setting A and a second setting B are valid.

With the first setting, the engine speed is regulated in accordance with the innovative method, where N (p) = 430 + 20.7p, Os p s X, where X is 15.8.

N (p) = G, p z X, where G is 750 rpm.

The first working area of the first setting is designated A in Fig. 3c.

Here, G corresponds to the engine speed value EGR1, which can provide a maximum output engine torque T1.

With the second setting, the engine speed is regulated in accordance with the innovative method, where N (p) = 430 + 20.7p, Osp SX, where X is 30.7.

N (p) = G, p 2 X, where G is 1100 rpm.

The second working area of the second setting is designated B in Fig. 3c.

The second range B comprises the first operating range A. Here, G corresponds to the engine speed value EGR2, which can provide a maximum output engine torque T2.

This case may correspond to a case where the vehicle has a locked differential gear.

It should be noted that if a differential gear is locked, a certain time delay of the start position activation should be considered, as the locking procedure may require a certain time before full engagement has been achieved. In accordance with an embodiment of the invention, a temporary increase in the maximum engine speed of the vehicle is handled. 10 15 20 25 534 1GB 18 If the first vehicle condition is present and the accelerator pedal is depressed to a so-called "kickdown" position and the clutch pedal are depressed more than eg 80% of the potential pedal path, maximum engine speed is increased, corresponding to a fully depressed accelerator pedal, stepwise to a second pedal limit, eg 31% of the potential pedal path. the stepwise increase can be in the range [10-40] revolutions per minute / second.

When the other vehicle condition is present and the vehicle's speed exceeds e.g. At 10 km / h, the vehicle's normal driving program is activated. This function enables a temporary increase of the maximum engine speed when needed. This advantageously improves the drivability of a vehicle in a situation where high driving resistance occurs. In addition, it is not too easy to temporarily increase the maximum engine speed, which reduces the risk of aggressive driving behavior. Furthermore, the kickdown functionality becomes available for a variety of vehicles.

It should be noted that the physical pedal position is not limited, but that the method in accordance with one aspect of the invention relates to a limitation of the signal regarding the accelerator pedal position. In other words, the value p is limited if the first state exists. Consequently, in this way, the required engine speed of the vehicle is limited in accordance with the invention.

Figure 4 schematically shows a method for improving the drivability of a motor vehicle in accordance with an aspect of the invention.

The method comprises a first method step s410. The method step s410 comprises the step of receiving at least one input signal 1DS in a control unit 200 in the vehicle, e.g. an electronic motor control unit. The received input signal lDS includes information about a desired motor speed value. The signal PS__1N, which is imaged with reference to e.g. Figs. 3a and 3b, can be embedded in the input signal IDS. In addition, the IDS includes information on the current engine speed, which gear is engaged, etc., and which can be used to determine whether a first vehicle permit exists or not. Received lDS 10 15 20 25 30 534 'IBS 19 will be processed in the control unit 200. After method step s410, subsequent method step s415 is performed.

The method step s415 comprises the step of receiving input data in a control unit in the vehicle, e.g. an electronic engine control unit, and determining whether a first vehicle condition exists. A first vehicle condition includes, in accordance with an example, at least one of the following: a) The vehicle is stationary and the engine is idling; b) The vehicle is essentially stationary; c) The vehicle starts moving, in either direction, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h; d) The vehicle is in motion, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h, with the clutch disengaged; or e) The vehicle is in motion, at a speed below a predetermined relatively low speed, e.g. less than 5 km / h or 7 km / h, with the clutch disengaged for a predetermined period of time, e.g. 2 seconds.

If one or more of the above vehicle conditions a-e exist, it is determined that the first vehicle condition exists.

If it is determined that the first vehicle condition exists in accordance with the above, a subsequent method step s420 is performed.

If it is determined that the first vehicle permit in accordance with the above does not exist, method step s410 is performed again, i.e. an updated lDS is received.

Method step s42O includes the step of activating the starting position of the vehicle. More specifically, if it has been determined that the first vehicle condition exists, the controller 200 activates a routine for handling engine speed data in accordance with the present invention. In accordance with an example, the logic unit 320 is activated and the logic unit 310 is deactivated, which means that the control function regarding engine speed in accordance with the invention is activated. This is described in more detail with reference to e.g. Fig. 3b. After method step s420, subsequent method step s423 is performed.

Method step s423 includes the step of processing data regarding the currently requested engine speed. The driver uses the actuator 220, e.g. an accelerator pedal, to request a certain engine speed. The requested motor speed is processed in the logic unit 320. As described above, the motor in this phase is regulated in such a way that an actual motor speed in excess of the preset value G is not provided. It should be noted that the first input signal regarding motor speed PS_1N is supplied to the control unit 200, where the last received first input signal regarding motor speed PS_1N is processed. After method step s423, subsequent method step s425 is performed.

During method step s423, a first output signal regarding motor speed PS_OUT * is output. It is this signal that is used to regulate the vehicle's engine in accordance with the above illustration with reference to e.g. Fig. 3b.

The method step s425 comprises the step of receiving input data in a control unit in the vehicle, e.g. an electronic engine control unit, and determining whether a second vehicle permit exists. A second vehicle condition comprises, in accordance with an example, at least one of the following: a) The accelerator pedal is in a predetermined position, e.g. in its top position; b) The vehicle's clutch is engaged, ie. engine speed and input rotational frequency are essentially equivalent; 10 15 20 25 30 534 166 21 c) The vehicle's clutch has been engaged, after a gear change has been made; d) The vehicle starts moving, in either direction, at a speed exceeding a predetermined speed, e.g. exceeding 7 km / h; e) The vehicle begins to move at a speed exceeding a predetermined speed, e.g. exceeding 7 km / h, with the clutch engaged; f) The vehicle starts moving, at a speed exceeding a predetermined speed, e.g. exceeding 7 km / h, with the clutch engaged since a predetermined time period, e.g. 1 second; or g) The clutch pedal is in its uppermost position.

If one or more of the above vehicle conditions a-g exist, it is determined that the other vehicle condition exists.

If it is determined that the second vehicle condition in the above exists, a subsequent method step s430 is performed. in accordance with If it is determined that the second vehicle permit in accordance with the above does not exist, method step s423 is performed again, i.e. an updated first input signal regarding motor speed PS_lN is received.

After method step s425, subsequent method step s430 is performed. Method step s430 includes the step of deactivating the vehicle's start position. More specifically, if it has been determined that the second vehicle condition exists, the controller 200 deactivates the routine for handling engine speed data in accordance with the present invention. According to an example, the logic unit 310 is activated and the logic unit 320 is deactivated, which means that the motor speed control function in accordance with the invention is deactivated. This is described in more detail with reference to e.g. Fig. 3a. Here, the output motor torque can be regulated step by step if the actual output motor torque is less than the maximum motor torque. This provides a smooth procedure for deactivating the engine speed control function in accordance with the invention.

After method step s430, the method ends.

Figure 5 shows an embodiment of the electronic control unit 200. The electronic control unit 200 is also called an apparatus. The apparatus includes a useless memory 520, a data processing unit 510 and a read and write memory 550. The useless memory 520 has a first memory portion 530 where a computer program, e.g. an operating system, is stored to control the operation of the device. In addition, the apparatus includes a bus controller, a serial communication port, an I / O facility, an AID converter, a time and date input and transmission unit, an event counter and an interrupt unit (not shown). The non-volatile memory 520 also has a second memory portion 540.

A computer program P, including routines for improving the driveability of a vehicle in accordance with the invention, may be stored in an executable manner or in a compressed state in a separate memory 560 and / or in the read and write memory 550. The memory 560 is a useless memory , e.g. an hm memory, EPROM, EEPROM or ROM. Memory 550 and 560 are computer software products.

When it is stated that the data processing unit 510 performs a certain function, it is to be understood that the data processing unit 510 performs a certain part of the program stored in the separate memory 560, or a certain part of the program stored in the read and write memory 550. 510 may the data communication port 599 via the data bus 515. The incompetent memory The data processing unit communicating with a 520 is adapted for communication with the data processing unit 510 via a data bus 512. The separate memory 560 is adapted for communication with the data processing unit 510 via a data bus 511. Lock and 10 15 20 25 534 166 23 550 is the data processing unit 510 via a data bus 514. the write memory with adapted for communication Data relevant to the control program regarding engine speed in accordance with the invention are stored in the electronic control unit memory 550 or 560. The data is also stored in the electronic control unit memory 550 or 560. where this data can be used for e.g. determining the first and second vehicle condition, processing an initial motor speed input signal, generating an engine speed output signal, to enable motor speed control. The logic units 310 and 320 may be software stored in memory 550 or 560.

When data, e.g. the information in the first input signal regarding engine speed is received at the data port 599 from e.g. an accelerator pedal or from the gearbox control unit, this information is temporarily stored in the second memory part 540. After receiving received data is temporarily stored, the data processing unit 510 is initiated for code execution as described above.

The data processing unit 510 is arranged to regulate the engine speed in the starting phase of the vehicle.

Parts of the method described herein may be performed by the apparatus by means of the data processing unit 510 running the program stored in the separate memory 560 or the read and write memory 550. When the apparatus runs the program, parts of the method described herein are executed.

In accordance with one aspect of the invention, the apparatus is arranged to run a computer program comprising machine readable facilities causing the electronic control unit or another computer connected to the electronic control unit to perform the following steps: - determining if a first vehicle condition exists; - on the basis of the existence of said first vehicle permit, determine whether a requested engine speed / number, as a result of operating an actuator, exceeds a preset engine speed value; IBS 24 - if the requested engine speed exceeds said preset engine speed value, generate an engine speed speed output signal to control said engine speed to prevent said ragged engine speed value from exceeding said preset engine speed value.

The invention also relates to a computer program product which comprises a computer program for improving the drivability of a vehicle and a machine-readable medium on which the computer program is stored. The invention also relates to a computer, e.g. an embedded electronic control unit or a vehicle external computer, which comprises a storage medium and a computer program for improving the drivability of a vehicle, and which is stored on the storage medium.

Claims (21)

Claims

1. Method for improving driveability of a motor vehicle (100, 110) having afirst vehicle state of condition relating to the starting-off phase, and asecond vehicle state of condition relating to the driving phase, said motorvehicle comprising a power actuating member (220) for requesting engine speed of said vehicle, said method comprising the steps of:- determining whether the first vehicle state of condition is fulfilled;characterized by - on the basis of said first condition being fulfilled, determining whether anengine speed requested by means of actuating said power actuating member exceeds a preset engine speed value; - if the requested engine speed exceeds said preset value (G), generatingan engine speed output signal (PS_OUT*) for controlling the engine speedso as to prevent said controlled engine speed from exceeding said preset engine speed value (G).

2. Method according to claim 1, wherein said preset engine speed value(G) is within the range of 500-1500 rpm.

3. Method according to claim 2, wherein said preset engine speed value(G) is within the range of 650-850 rpm.

4. Method according to claim 2, wherein said preset engine speed value(G) is within the range of 1000-1200 rpm.

5. Method according to any of claims 1-4, wherein said first vehicle state ofcondition comprises at least one of:a) The vehicle is standing still, and the engine is running at idle speed; b) The vehicle is standing substantially still; 26 c) The vehicle is moving, in either direction, at a speed less than apredetermined relatively low speed, e.g. less than 5 km/h, or 7km/h; d) The vehicle is moving at a speed less than a predetermined relativelylow speed, e.g. less than 5 km/h, or 7km/h, having the clutch disengaged;or e) The vehicle is moving at a speed less than a predetermined relativelylow speed, e.g. less than 5 km/h, or 7km/h, having the clutch disengaged during a predetermined time period, e.g. 2 seconds.

6. Method according to any of claims 1-5, wherein, in the step ofdetermining whether a request of engine speed exceeds a preset enginespeed value, the request is generated on the basis of a relative position of the power actuating member.

7. Method according to any of claims 1-6, wherein the power actuating member (220) comprises an accelerator pedal (220).

8. Method according to any of claims 1-7, further comprising the steps of:- determining whether the second vehicle state of condition is fulfilled;characterized by - on the basis of said second condition being fulfilled, generating anengine speed output signal (PS_OUT) for controlling the engine speed on the basis of said requested engine speed.

9. Method according to any of claims 1-8, wherein said second vehicle state of condition comprises at least one of: a) The accelerator pedal is in a predetermined position, e.g. in anuppermost position;b) The clutch of the vehicle has been engaged, i.e. engine speed and input shaft speed is substantially the same; 27 c) The clutch of the vehicle has been engaged, after a gear change hasoccurred; d) The vehicle is moving, in either direction, at a speed higher than apredetermined speed, e.g. more than 7km/h; d) The vehicle is moving at a speed higher than a predetermined speed,e.g. above 7km/h, having the clutch engaged; e) The vehicle is moving at a speed higher than a predetermined speed,e.g. more than 7km/h, having the clutch engaged since a predeterminedtime period, e.g. 1 second; or f) The clutch pedal is in an uppermost pedal position.

10. Computer program for improving driveability of a motor vehicle (100,110) having a first vehicle state of condition relating to the starting-offphase, and a second vehicle state of condition relating to the drivingphase, said motor vehicle comprising a power actuating member (220) forrequesting engine speed of said vehicle, comprising computer readableprogram code means for causing an electronic control unit (200) oranother computer connected to the electronic control unit (200) to performthe steps of: - determining whether the first vehicle state of condition is fulfilled; characterized by - on the basis of said first condition being fulfilled, determining whether anengine speed requested by means of actuating said power actuating member (220) exceeds a preset engine speed value (G); - if the requested engine speed exceeds said preset value (G), generatingan engine speed output signal (PS_OUT*) for controlling the engine speedso as to prevent said controlled engine speed from exceeding said preset engine speed value (G). 28

11. Computer program according to claim 10, comprising computerreadable means, wherein said preset engine speed value (G) is within therange of 500-1500 rpm.

12. Computer program according to claim 11, wherein said preset engine speed value (G) is within the range of 650-850 rpm.

13. Computer program according to claim 11, wherein said preset engine speed value (G) is within the range of 1000-1200 rpm.

14. Computer program according to any of claims 10-13, wherein said first vehicle state of condition comprises at least one of: a) The vehicle is standing still, and the engine is running at idle speed; b) The vehicle is standing substantially still; c) The vehicle is moving, in either direction, at a speed less than apredetermined relatively low speed, e.g. less than 5 km/h, or 7km/h; d) The vehicle is moving at a speed less than a predetermined relativelylow speed, e.g. less than 5 km/h, or 7km/h, having the clutch disengaged;or e) The vehicle is moving at a speed less than a predetermined relativelylow speed, e.g. less than 5 km/h, or 7km/h, having the clutch disengaged during a predetermined time period, e.g. 2 seconds.

15. Computer program according to any of claims 10-14, wherein, in thestep of determining whether a requested engine speed exceeds a presetengine speed value (G), the requested engine speed is generated on the basis of a relative position of the power actuating member.

16. Computer program according to any of claims 10-15, wherein the power actuating member (220) comprises an accelerator pedal (220).

17. Computer program according to any of claims 10-16, further comprising the steps of: 29 - determining whether the second vehicle state of condition is fulfilled;characterized by - on the basis of said second condition being fulfilled, generating anengine speed output signal (PS_OUT) for controlling the engine speed the basis of said requested engine speed.

18. Computer program according to any of claims 10-16, wherein saidsecond vehicle state of condition comprises at least one of: a) The accelerator pedal is in a predetermined position, e.g. in anuppermost position; b) The clutch of the vehicle has been engaged, i.e. engine speed andinput shaft speed is substantially the same; c) The clutch of the vehicle has been engaged, after a gear change hasoccurred; d) The vehicle is moving, in either direction, at a speed higher than apredetermined speed, e.g. more than 7km/h; d) The vehicle is moving at a speed higher than a predetermined speed,e.g. above 7km/h, having the clutch engaged; e) The vehicle is moving at a speed higher than a predetermined speed,e.g. more than 7km/h, having the clutch engaged since a predeterminedtime period, e.g. 1 second; or f) The clutch pedal is in an uppermost pedal position.

19. Computer, such as an embedded electronic control unit (200) or avehicle external computer comprising a storing means and a computerprogram according to any of claims 10-18 stored in the storing means.

20. Vehicle comprising a computer according to claim 19.

21. Vehicle according to claim 20, wherein said vehicle is heavy vehicle, such as a truck or bus.