• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a method of driving a vehicle (100), said vehicle (100) comprising an internal combustion engine (101) having at least one combustion chamber, said vehicle (100) further comprising means for pressurizing air for supply to said combustion chamber, and wherein said vehicle (100) further comprises at least a first braking system. The method comprises: - in reducing a torque request from a second level to a first, compared to said second level lower, level, determining whether said first braking system is activated, and - if said first braking system is activated, maintaining the pressure of said to said combustion supplied air at a higher second pressure (P1), compared to a first pressure (P1) required at said first level. 2
    公开号:SE1250777A1
    申请号:SE1250777
    申请日:2012-07-05
    公开日:2014-01-06
    发明作者:Martin Evaldsson
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    lO l5 typical cruising speed for the internal combustion engine, where the cruising speed is adapted for a certain cruising speed. Typical cruising speeds, depending on the region and / or type of road, can e.g. be 80 km / h, 85 km / h or 89 km / h.
    In addition to fuel economy, it is becoming increasingly important for heavy vehicles that the vehicle's driving is experienced as comfortable and intuitive for the vehicle's driver. For example. For example, the use of automatic gearboxes, where gearing is controlled, in whole or in part, by the control system normally present in the vehicle can facilitate the operation of the vehicle.
    Automatic shifting also enables additional degrees of freedom in controlling the vehicle's progress from a fuel economy perspective, e.g. by using the vehicle's control system to ensure that the vehicle is driven in a gearbox that is advantageous from a fuel consumption point of view.
    However, good driver comfort also means other aspects, such as e.g. to ensure good driveability, ie. that the vehicle from a performance point of view at e.g. a torque request responds in a manner expected by the driver, and moreover without undesired delay.
    SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of driving a vehicle which can further reduce the fuel consumption of vehicles powered by an internal combustion engine, while the method provides good drivability when driving the vehicle. This object is achieved with a method according to claim 1.
    The present invention relates to a method of driving a vehicle, said vehicle comprising an internal combustion engine, such as e.g. a diesel engine, having at least one combustion chamber, said vehicle further comprising means for pressurizing air for supply to said combustion chamber, and said vehicle further comprising at least a first braking system. The method comprises: - in reducing a torque request from a second level to a first, compared to said second level lower, level, determining whether said first braking system is activated, and - if said first braking system is activated, maintaining the pressure of said to said combustion supplied air at a higher second pressure, compared with a first pressure required at said first level.
    As mentioned above, it is desirable that a vehicle can be driven as fuel efficiently as possible, and as long as the vehicle is driven at a constant speed along a horizontal road, the vehicle's fuel efficiency will be controlled by, among other things, how close the optimum efficiency of the internal combustion engine operates.
    At the same time, it is often important that the vehicle shows good drivability, and in e.g. a torque request from the driver of the vehicle can respond quickly with an expected increase in torque delivered.
    Internal combustion engines, such as e.g. diesel engines, may depend on a compression of the combustion air supplied to the combustion in order to emit a high torque / high power, and in order to obtain good drivability a control is applied in many situations where the pressure of the air supplied to the combustion is maintained at a higher pressure than what is actually required from the combustion point of view. With the aid of the higher pressure, an air margin is created, which means that a certain increase of a supplied amount of fuel can be carried out without the air 10 l5 / fuel ratio during combustion falling to too low a value, whereby the power of the internal combustion engine can be made available more quickly. The air margin thus improves the vehicle's performance, and thus driveability, from a driver's perspective.
    A disadvantage of applying such an air margin, i.e. maintaining the air supplied to the combustion at a higher pressure, compared with a required pressure, is that a larger gas exchange work is carried out by the combustion engine, with associated losses as a result.
    By determining according to the present invention whether a braking system is activated, i.e. whether a braking force is applied to counteract the travel of the vehicle in the direction of travel, and, in the case said braking system is activated, maintaining the pressure of the air supplied to the combustion at a higher pressure, the combustion air pressure can be maintained without any increase in losses.
    Since a braking system is activated, losses will still occur in the form of the energy converted by the braking system, such as e.g. in the form of heat. By maintaining according to the present invention a high pressure for the air supplied to the combustion, with increased gas exchange work, and thus engine braking force, as a result, applied braking force can instead be reduced to a level corresponding to the losses caused by increased gas exchange work.
    Since decelerated energy is often decelerated in a way where the energy is not used for later use, the present invention has the advantage that even if the losses during braking are essentially the same, the higher combustion air pressure will lead to better drivability, ie. the vehicle will be able to be driven with a better response, ie. is experienced more vigorously by the driver of the vehicle because a greater IO force will be immediately available when needed, e.g. if a deceleration is immediately followed by an acceleration with a high torque requirement. The invention thus has as a result that the vehicle can often be driven with high available power when needed without adversely affecting fuel consumption.
    According to one embodiment of the invention, it is determined only whether a braking system is activated as above, while according to another embodiment of the present invention it is also determined whether an applied braking force exceeds any applicable first braking force. This first braking force can e.g. consists of a braking force corresponding to the braking force obtained by increased gas exchange work according to the present invention.
    According to one embodiment, it is determined whether a service braking system is activated, while according to another embodiment, it is determined whether any other braking system present at the vehicle is activated.
    According to an embodiment of the present invention, it is determined whether any braking system is activated, and as long as no braking system is activated, the pressure of the air supplied to the combustion is maintained at a higher pressure compared to a required pressure for a first time as long as no braking system is activated. while if at least one braking system is activated, the pressure of the air supplied to the combustion is maintained for a second time compared with the said first time for a longer time. Since the increase in losses caused by higher air pressure is offset by losses caused by the braking system, the period of time during which the combustion air pressure is maintained can be allowed to be longer than is normally the case.
    According to one embodiment, the combustion air pressure is maintained, provided that a braking system is activated, as long as possible, ie. the combustion air pressure is maintained for as long as 10 as long as a braking force is applied. Since the combustion air pressure is usually produced by means of a turbocharger driven by exhaust gases from the combustion, and since the internal combustion engine during braking is usually driven with little or no fuel supply, the resulting low exhaust gas flow will result in the combustion air pressure dropping after a while. the entire deceleration.
    Additional features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments and the accompanying drawings.
    Brief Description of the Drawings Fig. 1A shows a driveline of a vehicle to which the present invention can be applied; Fig. 1B shows a control unit in a vehicle control system; Fig. 2 shows an exemplary method according to the present invention; Fig. 3 shows an example of driving a vehicle with retention of a combustion air pressure; Fig. 4 shows an example of driving a vehicle with a combustion air pressure retention according to an embodiment of the present invention; Fig. 5 shows a further exemplary method according to the present invention; Fig. 6 shows yet another exemplary method according to the present invention; Detailed Description of Embodiments Fig. 1A schematically shows a driveline in a vehicle 100 according to an embodiment of the present invention. The vehicle 100 schematically shown in Fig. 1A comprises only one axle 104, 105 with drive wheels 113, 114, but the invention is also applicable to vehicles where more than one axle is provided with drive wheels, as well as to vehicles with one or more additional axles, such as one or more support shafts. The driveline comprises an internal combustion engine 101, which in a conventional manner, via a shaft outgoing on the internal combustion engine 101, usually via a flywheel 102, is connected to a gearbox 103 via a clutch 106. The clutch 106 may be a manually or automatically controlled clutch of known and the gearbox 103 may be arranged to be shifted by the driver of the vehicle 100 or automatically by the control system of the vehicle. According to an alternative embodiment, the vehicle 100 is provided with a clutch-free driveline.
    A shaft 107 emanating from the gearbox 103 then drives the drive wheels 113, 114 via an end gear 108, such as e.g. a conventional differential, and drive shafts 104, 105 connected to said final gear 108.
    The present invention relates to internal combustion engines, in particular diesel engines, in which the amount of air supplied to an internal combustion chamber, such as e.g. a cylinder, can be actively regulated.
    In the case of a diesel engine without the possibility of actively regulating the air supplied to the combustion, the combustion air available during combustion will consist of the air sucked in during the downward movement of the piston, where this intake air consists of air sucked in from the vehicle's surroundings. The amount of air during combustion thus becomes essentially the same for each combustion cycle (where variations may occur, for example, depending on external factors, such as prevailing air pressure, temperature, etc.).
    This means that only a certain amount of fuel can be injected before the combustion's air-fuel ratio (AFP) becomes undesirably low. The ratio of a stoichiometric ratio AFPSwk to the actual ratio of air to fuel supplied to the combustion (the ratio of the mass of air (kg) to petrol (kg) supplied to the combustion is generally called the lambda value, Ä, where the APR lambda value is defined as Än = --- As is well known, and AFR noise as appears from the equation means a lambda value = l a fuel / air ratio where stoichiometric combustion is obtained, ie. AFP = AFRm fi h and where larger and smaller lambda values mean excess air and air deficit during combustion. As is known, however, there are methods for increasing the effect of e.g. diesel engines by, by means of compression of the air supplied to the combustion, supplying a larger air mass to the combustion, whereby the larger air mass means that a correspondingly larger amount of fuel can be supplied while maintaining the air / fuel ratio, and thus higher power development, as a result.
    The compression of supplied air can, as is known, be accomplished in various ways. For example. the compression can be effected by means of a turbocharger 119, such as e.g. a VGT (Variable geometry turbocharger) unit or a turbo unit with dump valve (waste gate).
    With the help of e.g. such, or other applicable, turbochargers can thus be compressed by the air supplied to the combustion, whereby thus also lambda values can be regulated since different amounts of air can be supplied for any given amount of supplied fuel.
    However, an increase in the lambda value Ä for a given operating point usually also requires a certain increase in the amount of fuel supplied.
    This is because the supply of a larger amount of air will result in a larger gas exchange work, with associated losses, which may mean that an increase in the amount of fuel supplied is required to overcome losses caused by increased gas exchange work so that a desired flywheel torque can still be maintained.
    As has been mentioned above, however, a certain amount of compression is often required in order for the vehicle to show good drivability from a driver's perspective, even though this leads to increased fuel consumption. The present invention relates to a method for utilizing and maintaining compression in situations when this does not entail any increased cost in driving the vehicle.
    An exemplary method 200 according to the present invention is shown in Fig. 2, and the invention may be implemented in any applicable control unit, such as e.g. the control unit 117 shown in Fig. 1A.
    In general, control systems in modern vehicles usually consist of a communication bus system consisting of one or more communication buses for interconnecting a number of electronic control units (ECUs), or controllers, and various components arranged on the vehicle. Such a control system can comprise a large number of control units, and the responsibility for a specific function can be divided into more than one control unit.
    For the sake of simplicity, Fig. 1A shows only the control units 116, 117, 118, but vehicles 100 of the type shown often comprise considerably more control units, which is well known to those skilled in the art.
    In the present example, the clutch is an automatically controlled clutch, the control unit 116 controlling the clutch 106 via a clutch actuator (not shown) as well as the gearbox 103.
    The control unit 118 constitutes a brake control unit and is responsible for one or more brake system functions. For example. the vehicle 100 comprises a service braking system, which customarily e.g. may comprise brake discs with associated brake pads (not shown) arranged next to each wheel, and the abutment pressure of the brake pads against the brake discs is controlled by the brake control unit 118, which in a known manner sends signals to the regulator (s) regulating braking force in the service braking system. The brake control unit 118 can e.g. be arranged to control only the vehicle's service braking system, but may also be arranged to control one or more of the vehicle's other braking systems, where such occur. For example. the vehicle may include a retarder as below, and / or other auxiliary brake systems such as the exhaust brake and engine brake. Based on applicable commands from e.g. drivers or other control units, control signals are sent to the applicable system modules for requesting the desired braking force.
    The control unit 117, in which the present invention in the illustrated embodiment is implemented, controls the engine 101 of the vehicle 100. The invention may alternatively be implemented in a control unit dedicated to the present invention, or wholly or partly in one or more other control units already present with the vehicle 100.
    The control of the control unit 117 (or the control unit (s) to which the present invention is implemented) switching time according to the present invention will probably depend on signals received from other control units (also not shown) arranged at the vehicle, and / or information from t .ex. various sensors / sensors arranged at the vehicle. In general, control units of the type shown are normally arranged to receive sensor signals from different parts of the vehicle 100.
    Control units of the type shown are likewise usually arranged to emit control signals to various vehicle parts and vehicle components.
    The control is often controlled by programmed instructions. These programmed instructions typically consist of a computer program, which when executed in a computer or controller causes the computer / controller to perform the desired control, such as method steps of the present invention.
    The computer program usually forms part of a computer program product, the computer program product comprising an applicable storage medium 121 (see Fig. 1B) with the computer program 126 stored on said storage medium 121.
    Said digital storage medium 121 may e.g. consists of someone from the group: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically Erasable PROM), a hard disk drive, etc., and be arranged in or in connection with the control unit, the computer program being executed by the control unit. By changing the instructions of the computer program, the behavior of the vehicle in a specific situation can thus be adapted.
    An exemplary control unit (control unit 117) is shown schematically in Fig. 1B, wherein the control unit may in turn comprise a calculation unit 120, which may consist of e.g. any suitable type of processor or microcomputer, e.g. a Digital Signal Processor (DSP), or an Application Specific Integrated Circuit (ASIC). The computing unit 120 is connected to a memory unit 121, which provides the computing unit 120 e.g. the stored program code 126 and / or the stored data computing unit 120 is needed to be able to perform calculations. The calculation unit 120 is also arranged to store partial or final results of calculations in the memory unit 121.
    Furthermore, the control unit 117 is provided with devices 122, 123, 124, 125 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 122, 125 may be detected as information for processing the calculation unit 120. The output signals 123, 124 for transmitting output signals are arranged to convert calculation results from the calculation unit. 120 to output signals for transmission to other parts of the vehicle control system and / or the component (s) for which the signals are intended. Each of the connections to the devices for receiving and transmitting input and output signals, respectively, may be one or more of a cable; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems Transport), or any other bus configuration; or by a wireless connection. Returning to the method 200 shown in Fig. 2, this begins in step 201, where it is determined whether the pressure P for the combustion air exceeds any applicable greyhound Phmb The greyhound Pina can e.g. be set to a pressure above which the combustion air pressure consists of an overpressure, ie. a pressure exceeding the prevailing atmospheric pressure. Thus, the border care Ping can e.g. consists of atmospheric pressure. According to a preferred embodiment, however, the boundary value Plm fl consists of a higher pressure, compared with the prevailing atmospheric pressure, such as any applicable pressure exceeding the atmospheric pressure. For example. 13 the limit value Pina may consist of any applicable proportion of the maximum pressure to which the combustion air can be pressurized when driving a vehicle. For example. For example, the limit value Plmd may consist of any applicable proportion in the range of 70-100% of the maximum pressure Bmx to which the combustion air is pressurized when the vehicle 100 is driven, typically at maximum load.
    As long as the pressure condition is not met, the process remains in step 201, while the process thus proceeds to step 202 when the combustion air pressure P exceeds the limit value Plm fl. In step 202, it is determined whether the torque required by the internal combustion engine 101 is reduced. According to an embodiment of the invention, it is determined whether the torque demand is reduced to any applicable extent, such as e.g. by a certain number of percent or to any applicable level, such as any applicable percentage of maximum releasable torque. After the torque request has been reduced according to step 202, the procedure proceeds to step 203.
    This is illustrated at tl in Fig. 3, which shows an example of a function for improving the drivability of the vehicle 100 from e.g. a driver's condition. Fig. 3 shows how the fuel supply Q varies over time t when driving the vehicle 100 along a (not shown) section of road. At time t0 the vehicle 100 is driven with a high emitted torque from the internal combustion engine 101, and thus a relatively high fuel supply Q amounting to a level Q2, and at time t1 the torque demand is reduced, whereby fuel supply to the internal combustion engine 101 is reduced from level Q2 to a level Q1 corresponding reduction in torque delivered. At the same time, the combustion air pressure P of the air supplied to the combustion changes as shown in the figure. 14 The fuel demand Q of the vehicle 100 can decrease from the relatively high level Q to the relatively low level Qi, e.g. due to the driver of the vehicle 100 releasing the accelerator pedal, or due to the torque request being reduced by e.g. a cruise control function. At time t1, the propulsion demand thus decreases to a relatively low propulsion demand, but instead of simultaneously controlling the combustion air pressure P in such a way that it is reduced to as low a level as possible, with associated fuel saving as a result, the combustion air pressure P is kept substantially the level Pg all the way to the time tg, and only at this time tg is the combustion air pressure P lowered to a level P1, which from a fuel consumption point of view consists of a combustion air pressure P which gives rise to a more economical air / fuel ratio Ä, and which e.g. results in the lowest air / fuel ratio Ä allowed by e.g. current government regulations and / or e.g. from the point of view of smoke restriction.
    This functionality, referred to herein as Low Load Case (LLC), is intended to maintain a high combustion air pressure P, such as e.g. by maintaining a high turbo speed, for a certain period of time tH, i.e. between t1 and tg in Fig. 3, such as e.g. 1-3 seconds, even after a torque request has decreased. In this way the engine response is kept high during this predetermined time tH to ensure that a high force can be made available directly, or at least substantially directly, if the conditions for the vehicle's driving during said time tH become such that a high driving force is again required, e.g. may be the case if the torque demand is reduced due to shifting to another gear, in which case high power is often desirable immediately after the shift has been made, e.g. after a downshift in an uphill slope.
    If the combustion air pressure P is maintained at the pressure Pg during the time period tH, the fuel supply during this time period tH can be immediately raised again to the level Q2 without risk of the air / fuel ratio Ä being below an impermissible value, thus the entire torque taken between 3 directly, or at least substantially directly, is available when needed.
    According to the method shown in Fig. 2, the vehicle 100 is driven with the low load function exemplified in Fig. 3 activated, i.e. the pressure P of the air supplied to the combustion is maintained at a higher pressure for a first time after the torque demand has decreased. In step 203, therefore, a setpoint Pæf for the combustion air pressure P is set equal to P2, i.e. the engine control will strive to maintain the combustion air pressure P at the level Pg prevailing before the torque demand decreased at tl. At the same time, a timer is started after first being set to 0, after which the procedure proceeds to step 204. In step 204 it is determined whether the timer has reached the time limit, where the time limit tlmü is the time limit for said low load function, which as above can be 1-3 seconds. As long as the time limit tlmd has not been reached, the process remains in step 204 so that, when the time limit tina has been reached, it proceeds to step 205.
    In step 205, it is determined whether any applicable braking system is activated. For example. it can be determined whether the vehicle's service braking system is activated, alternatively whether something else is applicable, or alternatively whether any braking system at all, is activated. If it is determined in step 205 that this is not the case, ie. the service braking system, or, where applicable, the current other braking system, is not activated, the procedure proceeds to step 206 where the pressure setpoint Pmf of the combustion air pressure P when controlling the internal combustion engine 101 is set to the pressure P1 currently required, which e.g. can consist of the atmospheric pressure if the propulsion demand is low, and / or the pressure required to have the lowest air / fuel ratio Ä allowed by e.g. current government regulations and / or e.g. from the point of view of smoke restriction shall not be less than.
    The procedure then returns to step 201. Ie. in case no braking system is activated, the engine control works just as in the case where the vehicle 100 is driven with activated low load function.
    If, on the other hand, it is determined in step 205 that the applicable braking system is activated, the procedure proceeds to step 207, where the pressure setpoint Pæf for the combustion air pressure P is still maintained at the pressure prevailing before the reduction of the requested driving force, ie. in the present example the pressure P2.
    However, the pressure setpoint Pæf does not have to be set to the pressure Pb but can also constitute another applicable, but still compared with the pressure P1 higher, pressure, such as e.g. 70-100% of the pressure P2.
    The combustion air pressure P is thus maintained after the time t2 continued at a high level with larger combustion engine losses due to greater gas exchange work as above as a result.
    This is illustrated in Fig. 4, where also the braking torque L of the engine is illustrated, where L2 represents the total internal combustion engine losses at a combustion air pressure P2 as above, where L1 represents the total internal combustion engine losses at a reduction of the combustion air loss L1 and the difference L1. and L2 is completely caused by losses due to the larger gas exchange work at the combustion air pressure P2. These engine losses due to the larger gas exchange work can e.g. constitute a braking torque in the order of 50-100 newton meters, ie. engine losses increase by this value at a high maintained combustion air pressure. The difference with respect to Fig. 3 is illustrated in Fig. 4 by the pressure change according to Fig. 3 being indicated by dashed line 401, which thus already takes place at the time tg in Fig. 3. Likewise, dashed line 402 indicates the corresponding lower losses in gas exchange work which occur at the in Fig. 3 the previous reduction of the combustion air pressure.
    However, since the combustion air pressure according to the present invention is maintained when a braking system is activated, the increased engine losses can be compensated by a reduction in applied braking torque, i.e. the brakes can operate to a correspondingly lesser degree, whereby the total losses regarding engine losses and braking force losses can thus be kept at a constant level. According to the present invention, the high combustion air pressure can thus be maintained without any actual cost in the form of e.g. increased fuel consumption.
    This has the advantage that in cases where the vehicle 100 is to be accelerated rapidly again after braking, a large proportion of or all of the power (torque) the internal combustion engine l01 can generate will be substantially immediately available without the otherwise inevitable delay that occurs when the combustion air pressure first must be built up before full torque can be emitted by the internal combustion engine.
    The present invention also has the advantage that since the brakes can operate to a correspondingly lesser extent, a reduced brake system wear is obtained, e.g. with respect to brake pads or other components present in the vehicle's braking system. However, the reduced torque demand will usually mean that the combustion air pressure will not be able to be maintained for any length of time. For this reason, it is determined in step 208 whether the prevailing combustion air pressure exceeds any applicable limit value 18 Pina. This limit value PlmQ can be set to any applicable limit value, such as e.g. a value representing a level where the combustion air pressure has decreased to some applicable pressure due to the fact that the pressure can no longer be maintained, which often occurs when the reduced combustion engine work results in a reduced driving force (exhaust flow) for driving the turbocharger. The limit value Plmæ can e.g. represent the atmospheric pressure, or a pressure level in the vicinity thereof. The limit value PlmQ can e.g. also consists of the pressure currently required for the current driving demand, or an applicable pressure between the required combustion air pressure for the current driving demand and the pressure P2. Furthermore, the pressure setpoint Pæf can be arranged to change with time when the brake system is activated, and e.g. lowered to pressure P1 or the limit value Plmæ in any applicable way.
    When the combustion air pressure is below the limit value Phmh which is shown at time tg in Fig. 4, the process returns to step 201 via step 206 as above, while as long as the combustion air pressure exceeds said limit PlmQ the process returns to step 205 to determine whether any braking system is still activated. and as long as this is the case, the combustion air pressure P is maintained as far as possible. If it is then determined in step 205 that the braking system is no longer activated, the procedure returns directly to step 201 via step 206 as above.
    The invention thus enables maximum drivability to be maintained for as long as possible without causing increased losses.
    Furthermore, the criterion exemplified in step 207, instead of being controlled by the pressure to which the combustion air pressure P has decreased, can instead be controlled by a second timer, where this second timer counts for a time which, compared with the time tlmü, means that the combustion air pressure is maintained. during a compared to the time tlm fl longer time. This second timer can e.g. be arranged to be started at the same time as the timer th and thus count for one compared to the time tlmü longer time.
    Said second time can alternatively e.g. is counted from the activation of said braking system, whereby the second timer can count to a time which can be both longer and shorter compared to the time tlmü, but where the total time will thus exceed the time tlm fl. Transition from step 205 or step 207 to step 206 can thus, according to one embodiment, be arranged to take place when the second timer has reached a certain time, regardless of whether the braking system is still active, and regardless of whether the combustion air pressure P has not yet decreased to the level Piimz. The procedure shown in Fig. 2 may be arranged to be carried out as soon as a reduction of the requested torque occurs. Alternatively, the method can be arranged only at a larger reduction of the requested torque, such as e.g. only provided that the reduced torque demand is a maximum of 80% of the torque demand before reduction.
    According to the method shown in Fig. 2, the vehicle is driven with a low load function according to Fig. 3 activated. However, there are situations where it can be advantageous to drive the vehicle without such a low load function activated. An example of this is shown in the parallel Swedish application 1250775-2, entitled "PROCEDURES AND SYSTEMS FOR DRIVING VEHICLES II", with the same applicant as the present invention, where the vehicle can be driven according to a first mode and according to a second mode, and where in said second mode functions such as said low load function are deactivated when applicable in order to reduce fuel consumption.However, the present invention is still applicable even in eg situations such as 10 described according to the method described in said parallel patent application, or generally where low load function is missing.
    An example of a method according to the present invention in such situations is shown in Fig. 5. The process steps 501-502 shown in Fig. 5 correspond entirely to the process steps 201-202 in Fig. 2 and are therefore not explained in more detail. According to the method shown in Fig. 5, however, no retention of the combustion air pressure P is normally applied, which e.g. may be the case if such a function is completely absent, or if the vehicle is driven according to the said second mode according to the said parallel application "PROCEDURE AND SYSTEM WHEN DRIVING VEHICLE II".
    Thus, it is already determined in step 503 whether any braking system is activated. If not, the process proceeds to step 504, which corresponds to step 206 in Fig. 2, i.e. the setpoint Pmf for the combustion air pressure P is set immediately after the reduction of the torque demand in step 502 to the combustion air pressure required at the new torque level. According to this embodiment, the drivability of the vehicle is thus directly affected by a reduction in the requested torque as long as no braking system is activated.
    If, on the other hand, it is determined in step 503 that some braking system is activated, the process proceeds to step 505, which corresponds to step 207 in Fig. 2 and wherein the combustion air pressure P via steps 505-506 is then maintained as long as possible according to what is described. in connection with steps 207-208 in Fig. 2. Since the present invention does not give rise to increased fuel consumption when any braking system is activated, the invention thus allows the drivability of the vehicle to be maintained at a high level in many situations without giving rise to increased fuel consumption, and thus in many 21 situations enable a very good drivability even though the vehicle is actually driven in a way that prioritizes low fuel consumption before good drivability.
    As will be appreciated, 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.
    For example. the method with its method steps may adopt other embodiments within the scope of the present invention. For example. the method may be of the type shown in Fig. 6, where the process steps 601-602 are completely corresponded to the process steps 201-202 in Fig. 2.
    Instead of starting the timer tt directly as in Fig. 2, in Fig. 6 it is already determined in step 603 whether the braking system is active. If so, the procedure proceeds to steps 604-605, which correspond to steps 207-208 in Fig. 2, maintaining the combustion air pressure P as long as possible.
    In addition, the above-described embodiment with said second timer can also be applied here.
    If it is found in step 603 that the braking system is not active, the procedure proceeds to step 606, where said timer tt is set to zero and started as above. At the same time, just as in step 203 above, the setpoint P fl f for the combustion air pressure P is set equal to P2, after which the procedure proceeds to step 607, where it is determined whether the timer tt has reached the time limit ttm fl, where the time limit ttm fl is the time limit for said low load function. Once the time limit has been reached, the process proceeds to step 608, where it is again determined whether any applicable braking system is activated. If not, the process returns to step 601 via step 608 where the pressure setpoint Pmf of the combustion air pressure P is set to the pressure P1 currently required. On the other hand, if it is found that the applicable braking system is activated, the process proceeds to step 604 for maintaining the combustion air pressure as previously described.
    权利要求:
    Claims (18)
    [1]
    1.
    [2]
    A method of driving a vehicle (100), said vehicle (100) comprising an internal combustion engine (101) having at least one combustion chamber, said vehicle (100) further comprising means for pressurizing air for supply to said combustion chamber, and wherein said vehicle (100) further comprises at least a first braking system, characterized in that the method comprises: - in reducing a torque request from a second level to a first, compared to said second level lower, level, determining whether said first braking system is activated , and - if said first braking system is activated, maintain the pressure of said air supplied to said combustion at a higher second pressure (P1), compared with a first pressure required at said first level (P1).
    [3]
    The method of claim 1, wherein said method further comprises: - if said first braking system is activated, maintaining the pressure of said air supplied to said combustion at said second pressure (P2), and - if said braking system is not activated, adjusting the pressure for said air supplied to said combustion to a pressure substantially corresponding to said first pressure.
    [4]
    A method according to claim 1, wherein said method comprises: - if said first braking system is activated, maintaining the pressure of said air supplied to said combustion at said second pressure (P2) for a second time, and - if said braking system is not activated maintaining the pressure of said air supplied to said combustion at said second pressure (P2) for a first time, compared to said second time shorter.
    [5]
    The method of claim 3, further comprising, if said first braking system is activated during said first time, maintaining the pressure of said air supplied to said combustion substantially at said second pressure (P2) during said second time.
    [6]
    A method according to claim 4, wherein, if said first braking system is activated during said first time, the pressure of said air supplied to said combustion is maintained substantially at said second pressure (P fi during said second time, said second time being counted from the time said first time is counted, or from the time the said braking system is activated.
    [7]
    A method according to any one of claims 1-5, further comprising maintaining a pressure setpoint (Pmf) for the pressure of said air supplied to said combustion at said second pressure (P2) as long as said first braking system is activated.
    [8]
    A method according to any one of the preceding claims, further comprising, when said first braking system is activated, maintaining a pressure setpoint (Pn fi) for the pressure of said air supplied to said combustion at a higher pressure compared to said first pressure (P1) as long as the pressure of the air supplied to said combustion exceeds a limit value (Phm fi.
    [9]
    A method according to any one of claims 1 to 7, further comprising: - determining whether the braking force applied by said first braking system exceeds a first braking force, and
    [10]
    10.
    [11]
    11.
    [12]
    12.
    [13]
    13.
    [14]
    - maintaining a pressure setpoint (Pmf) for said air supplied to said combustion at a higher pressure compared to said first pressure (P1) if the braking force applied by said first braking system exceeds said first braking force. A method according to claim 8, wherein said first braking force corresponds to at least half of the braking force obtained by the difference between performed gas exchange work on pressurizing said combustion air to said second pressure (P2) and performed gas exchange work on pressurizing said combustion air to said first pressure (PU). A method according to any one of the preceding claims, wherein said first braking system is a service braking system A method according to any one of the preceding claims, wherein delivering the required torque at said second level requires a second, compared to an air pressure required at said first level, higher air pressure. A method according to any one of the preceding claims, wherein said second pressure (P2) constitutes 70-100% of the pressure required to deliver torque at said second level for the air supplied to the combustion. A method according to any one of the preceding claims, further comprising maintaining the pressure for said to said combustion ti Introduced air at said second pressure (P2) if said first braking system is activated, and if the torque required at said first level constitutes 0-80% of the torque required at said second level. A method according to any one of the preceding claims, wherein said first pressure is a pressure which essentially results in an air / fuel ratio constituting a
    [15]
    15.
    [16]
    16.
    [17]
    17.
    [18]
    18. 26 limit value permitted by the manufacturer or regulatory authority when driving said vehicle. 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 1-14. A computer program product comprising a computer readable medium and a computer program according to claim 15, wherein said computer program is included in said computer readable medium. A system for driving a vehicle (100), said vehicle (100) comprising an internal combustion engine (101) having at least one combustion chamber, said vehicle (100) further comprising means for pressurizing air for supply to said combustion chamber, and wherein said vehicle (100) further comprising at least one first braking system, characterized in that the system comprises: - means for determining, when a reduction of a torque request from a second level to a first, compared with said second level lower, level, said first braking system is activated , and means for, if said first braking system is activated, maintaining the pressure of said air supplied to said combustion at a higher second pressure (P1), compared with a first pressure (P1) required at said first level. Vehicle, characterized in that it comprises a system according to claim 17.
    类似技术:
    公开号 | 公开日 | 专利标题
    US7755309B2|2010-07-13|Drive system for a motor vehicle
    US8195370B2|2012-06-05|Association of torque requesting modules in a coordinated torque architecture
    JP5189173B2|2013-04-24|Compressed air supply control method for internal combustion engine and transmission
    US8437938B2|2013-05-07|Axle torque based cruise control
    CN104603429B|2017-06-30|The travel controlling system of vehicle
    JP2006076567A|2006-03-23|Device and method for calculating drive output distribution in hybrid power train for vehicle
    US20060178797A1|2006-08-10|Coordinated torque control security method and apparatus
    US10518764B2|2019-12-31|System and method for improving fuel economy for autonomous driving vehicles
    US20100198436A1|2010-08-05|Coordination of operating modes and torques for hybrid vehicle drives
    SE539477C2|2017-09-26|Control of an internal combustion engine in connection with freewheeling
    US9316274B2|2016-04-19|Method for operating a powertrain in a motor vehicle
    SE1250775A1|2014-01-06|Vehicle Driving Procedure and System ii
    JP2011126425A|2011-06-30|Vehicle control system
    SE1250777A1|2014-01-06|Vehicle Driving Procedure and System iii
    JP4600540B2|2010-12-15|Drive source control device
    JP4702429B2|2011-06-15|Drive source control device
    SE538916C2|2017-02-14|Procedure and system for adjusting the performance of a vehicle
    JP2019517953A|2019-06-27|Drive system control method and drive system
    SE1250774A1|2014-01-06|Procedure and systems for driving vehicles
    JP4483646B2|2010-06-16|Engine control device
    JP2013108412A|2013-06-06|Vehicle drive control device
    JP2010064645A|2010-03-25|Vehicle controller
    JP2009250085A|2009-10-29|Control device of driving source
    JP2010265857A|2010-11-25|Coasting control device
    JP5136653B2|2013-02-06|Powertrain control device and control method
    同族专利:
    公开号 | 公开日
    WO2014007751A1|2014-01-09|
    DE112013003031T5|2015-04-23|
    SE540017C2|2018-02-27|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JP2622994B2|1988-08-05|1997-06-25|株式会社いすゞセラミックス研究所|Control device for turbocharger with rotating electric machine|
    DE10202322A1|2002-01-23|2003-07-31|Daimler Chrysler Ag|Internal combustion engine with exhaust gas turbocharger has controller that controls turbine geometry if pressure in or upstream of turbine exceeds threshold to prevent turbine damage|
    MX2007010194A|2004-09-10|2008-11-04|Knorr Bremse Systeme|"torque deficiency" .|
    SE531171C2|2007-05-16|2009-01-13|Scania Cv Abp|A method for controlling an engine with VTG turbocharger|
    GB2464462B|2008-10-14|2012-12-26|Cummins Turbo Tech Ltd|Engine braking system|
    US8290689B2|2009-04-14|2012-10-16|GM Global Technology Operations LLC|Variable exhaust brake control via turbine vane positioning|
    US8069665B2|2010-04-15|2011-12-06|Ford Global Technologies, Llc|Stored compressed air management for improved engine performance|
    US8412424B2|2010-05-19|2013-04-02|Bendix Commercial Vehicle Systems Llc|Vehicle pneumatic booster system operating method and apparatus|
    JP2012097604A|2010-10-29|2012-05-24|Isuzu Motors Ltd|Method and device for controlling exhaust brake of internal combustion engine|
    法律状态:
    2021-03-02| NUG| Patent has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    SE1250777A|SE540017C2|2012-07-05|2012-07-05|Procedure and system for driving a vehicle, where the charge pressure is controlled|SE1250777A| SE540017C2|2012-07-05|2012-07-05|Procedure and system for driving a vehicle, where the charge pressure is controlled|
    DE201311003031| DE112013003031T5|2012-07-05|2013-07-04|Method, installation and computer program for delaying the reduction of the charge air pressure when activating the brakes|
    PCT/SE2013/050869| WO2014007751A1|2012-07-05|2013-07-04|Method, system and computer program for delaying reduction of charge air pressure if brakes are activated|
    [返回顶部]