Method and system for torque control during downshifts by matching a vehicle torque map to a shift pattern

Abstract

A method comprising: Controlling torque generation by an internal combustion engine of a vehicle so that a first torque is generated in an n-th gear before a downshift, which is determined according to a gearshift pattern of the vehicle, wherein the first torque is 100% of the torque available to the engine at a given accelerator pedal position and a given engine speed (rpm) (S415); Calculating a second torque that causes a predefined increase in engine power output based on a first engine power output that occurs when the engine produces the first torque at the given accelerator pedal position and the given speed (rpm) (S420); and Controlling the torque generation by the engine so that the second torque is generated in an (n-1)th gear after the downshift.

Description

(a) Technical area

[0001] The present invention relates generally to a vehicle control system, and more particularly to controlling (e.g., regulating) (hereinafter referred to as controlling) a vehicle internal combustion engine using an optimized torque map by matching the torque map to gear shift patterns. (b) Background technology

[0002] In general, the term "engine map" refers to a set of one- or multi-dimensional parameter tables loaded into a vehicle control unit (ECU), e.g., an electronic control unit (ECU), to control various engine parameters such as throttle position / opening, injection timing, and ignition timing (e.g., timing, duration, phase, etc.), and the like. One such map—a "torque map"—allows an operator to control engine drivability by redefining the torque delivery by the vehicle's engine. The torque map is a two-dimensional table with engine speed (e.g., speed or revolutions per minute (rpm)) and throttle or accelerator pedal position, measured using an accelerator pedal position sensor (APS), as inputs, and torque as output.

[0003] An operator can manipulate a vehicle torque map to define the vehicle's torque behavior. For example, Fig. 1A-1C show exemplary hypothetical torque maps 100 resulting in various engine behaviors. Each torque map 100 includes multiple APS lines indicating a range of throttle pedal positions (e.g., 10% APS corresponds to the throttle pedal being 10% depressed, 100% APS corresponds to the throttle pedal being fully depressed, etc.). Following a particular APS line and engine speed in rpm (x-axis) as inputs, the engine map 100 outputs a corresponding amount of torque (y-axis).

[0004] As shown in Fig. 1A, the motor delivers a constant torque. This means that for all rpm values, the torque produced by the motor remains constant for a given APS. On the other hand, as shown in Fig. 1B, the motor outputs a constant power. As is known in the art, power is the product of torque multiplied by a speed, in this case, rpm. Therefore, as the speed (rpm) of a motor increases, the motor torque decreases proportionally, and vice versa, so that a constant power is output. As a result, even if APS remains constant, the slope of the APS line changes due to the changing torque. As shown in Fig. 1C, a hybrid approach can be used that combines the constant torque map and the constant power torque map. Here, the torque strategy resembles constant torque at low and high speeds (rpm) and constant power at mid-speeds (rpm). It should be apparent that the vehicle torque map can be shaped in a variety of ways to influence the vehicle's drivability, e.g., to make the vehicle feel sportier, to increase the vehicle's hauling capacity, etc.

[0005] Torque maps are formulated for each vehicle gear. For this purpose, a base torque map can be defined (in first gear, for example), and a factor can be applied to the torque values ​​in each APS position of the base map to create torque maps in other gears. For example, Fig. 2 shows an exemplary hypothetical torque map factor table 200 containing factors (the factor for first gear is 1, since first gear represents the base torque map) by which the torque output is / is to be multiplied at varying APS positions for each gear. Therefore, after the base torque map is defined in one gear, torque maps can be easily defined in subsequent gears using the factor table 200.

[0006] Meanwhile, gearshift patterns or gearshift schedules dictate the driving conditions under which a vehicle changes gears—either upshifting or downshifting. In automatic transmission vehicles, a vehicle control unit, e.g., a transmission control unit (TCU), can control gearshifting based on throttle opening and vehicle speed / engine speed (rpm) as inputs. For example, Fig. 3 illustrates an exemplary hypothetical gearshift pattern 300 showing shift shapes for each gear. Here, a vehicle gear is shifted according to throttle opening and engine speed (RPM). For a given throttle in a given gear, there is a single vehicle speed at which a shift occurs. Note that the gearshift pattern 300 specifically describes a downshift pattern; however, the procedure works similarly for upshifts.

[0007] Shift patterns are typically created with fuel economy, engine performance, and performance drivability in mind. In the shift pattern 300, fuel economy is accounted for by the minimum lines 310 in the shift pattern. Conversely, the maximum lines 320 are created with knowledge of engine performance. Furthermore, the center pedal region 330 can be adjusted to achieve a desired response or feel. Common practice includes adjusting a vehicle shift pattern to address drivability concerns, such as sluggish acceleration where the vehicle does not adequately respond to a driver pressing the accelerator pedal, busy gear shifting, and the like.

[0008] Like influencing a vehicle's torque map, influencing a gearshift pattern can modify a vehicle's drivability. However, adjusting the torque map without considering the gearshift pattern, or vice versa, can create drivability issues, primarily due to gear ratios. For example, the engine response may feel sluggish while the accelerator pedal is depressed due to torque saturation (e.g., the engine has reached the maximum amount of available torque in a current gear). This means the driver may not feel a level of acceleration in the current vehicle gear.

[0009] The problem arises because there's no sense of torque reserve across all gears. Also, after downshifting, the immediate acceleration response can feel excessive and jerky to the driver and passengers. The result is a driving experience that feels discontinuous and unpredictable.

[0010] From DE 11 2009 000 613 T5 a method for controlling torque generation by an internal combustion engine of a vehicle is known, in which a first torque is generated in an n-th gear before a downshift, which is determined according to a gearshift pattern of the vehicle. Description of the invention

[0011] The object of the present invention is to provide a method and system that utilize a vehicle torque map tailored to gearshift patterns to maintain a power reserve in the vehicle engine to prevent the feeling of a sluggish response during acceleration and an uneven response to a downshift. The present invention further aims at combining torque map and shift pattern concepts to achieve improved drivability and at using a shift pattern-optimized torque map disclosed herein to ensure improved responsiveness and prevent a phenomenon of a dead response before a downshift followed by excessive acceleration after the downshift. The present invention is also to achieve drivability with smoother acceleration and greater predictability as a result.

[0012] These objects are achieved by a method according to claim 1, by a system according to claim 8, and by a non-transitory computer-readable medium containing program instructions for carrying out a method according to claim 9. Advantageous embodiments are the subject of the dependent claims.

[0013] According to the present invention, a method comprises: controlling torque generation by an internal combustion engine of a vehicle such that a first torque is generated in an n-th gear before a downshift determined according to a gearshift pattern of the vehicle, the first torque being 100% of the torque available from the engine at a given accelerator pedal position and a given engine speed (revolutions per minute (rpm)); calculating a second torque causing a predetermined increase in engine power output based on a first engine power output occurring when the engine generates the first torque at the given accelerator pedal position and the given speed (rpm); and controlling torque generation by the engine such that the second torque is generated in an (n-1)-th gear after the downshift.

[0014] Calculating the second torque may include: determining a first engine power output that occurs when the engine produces the first torque at a given speed (rpm); calculating a second engine power output equivalent to the first engine power output increased by the predetermined increase in engine power output; and calculating the second torque based on the second engine power output.

[0015] The given accelerator pedal position may be between approximately 30% and approximately 70%, and the given engine speed or engine rpm (in short: engine speed) may be between approximately 500 rpm and approximately 4,000 rpm.

[0016] The method may further comprise: forming a torque line from a vehicle torque map for the n-th gear based on the first torque; and forming a torque line from a vehicle torque map for the (n-1)-th gear based on the second torque.

[0017] Additionally, the method may further comprise: determining a plurality of first torques corresponding to a plurality of points on the gear shift pattern for the n-th gear; forming a vehicle torque map including a plurality of torque lines for the n-th gear, wherein the plurality of torque lines are formed based on the plurality of determined first torques; calculating a plurality of second torques corresponding to a plurality of points on the gear shift pattern for the (n-1)-th gear; and forming a vehicle torque map including a plurality of torque lines for the (n-1)-th gear, wherein the plurality of torque lines are formed based on the plurality of calculated second torques.

[0018] The predefined increase in engine power output can be defined by an operator. The predefined increase in engine power output can be an increase of between approximately 5% and approximately 30%.

[0019] Furthermore, according to the present invention, a system comprises: an (internal combustion) engine of a vehicle configured to generate torque resulting in the movement of the vehicle; and a control unit of the vehicle configured to: control torque generation by the engine such that a first torque is generated in an n-th gear before a downshift that determines (e.g.determined) according to a gearshift pattern of the vehicle, wherein the first torque is 100% of the torque available to the engine at a given accelerator pedal position and a given engine revolutions per minute (rpm); calculating a second torque causing a predefined increase in engine power output based on a first engine power output occurring when the engine is producing the first torque at the given accelerator pedal position and the given engine revolutions per minute (rpm); and controlling torque production by the engine such that the second torque is produced in an (n-1)th gear after the downshift.

[0020] Furthermore, according to the present invention, a non-transitory computer-readable medium containing program instructions for carrying out a method comprises: program instructions that control torque generation by an engine of a vehicle such that a first torque is generated in an n-th gear prior to a downshift determined according to a gearshift pattern of the vehicle (e.g.determined), wherein the first torque is 100% of the torque available to the engine at a given accelerator pedal position and a given speed / revolution per minute (rpm); program instructions that calculate a second torque that causes a predefined increase in engine power output based on a first engine power output that occurs while the engine is producing the first torque at the given accelerator pedal position and the given speed (rpm); and program instructions that control torque production by the engine such that the second torque is produced in an (n-1)th gear after the downshift. Short description of the drawings

[0021] The embodiments herein will be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals indicate identical or functionally similar elements, of which: Fig. 1A-1C show exemplary hypothetical torque maps resulting in different engine behaviors; Fig. 2 shows an exemplary hypothetical torque map factor table containing adjustment factors; Fig. 3 shows an exemplary hypothetical gearshift diagram showing shift shapes for each gear; Fig. 4 shows an exemplary simplified method for matching a torque map to shift patterns; Fig. 5 shows an exemplary diagrammatic representation of the downshift pattern-torque map relationship; Fig. 6A, Fig. 6B, Fig. 7A and Fig. 7B shows an exemplary process for optimizing the engine torque map according to the gear shift pattern; Fig. 8 shows an exemplary torque map shaped according to the gear shift patterns; and Fig. 9 is an exemplary diagrammatic flowchart of the procedure for tuning a torque map to shift patterns used in Fig. 4 are shown.

[0022] It should be understood that the drawings referred to above are not necessarily to scale, as they present a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment. Detailed description of the embodiments

[0023] The language used herein is for the purpose of describing particular embodiments and is not intended to limit the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will further be understood that the terms "comprising" and / or "including," when used in the description, specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more listed items. The term "coupled" or“Connected” indicates a physical relationship between two components whereby the components are connected either directly or indirectly through one or more intervening components.

[0024] It is understood that the term "vehicle" or "vehicular" or other similar term as used herein includes motor vehicles generally, such as passenger automobiles including sport utility vehicles, buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, an electric vehicle (EV) is a vehicle that, as part of its propulsion capabilities, has electrical power derived from an energy storage device (e.g., one or more electrochemical cells or another type of battery). An EV is not limited to an automobile and may include motorcycles, carts, scooters, and the like.Furthermore, a hybrid vehicle is a vehicle that has two or more power sources, for example both gasoline-based power and electric-based power (e.g., a hybrid-electric vehicle (HEV)).

[0025] Additionally, it is understood that one or more of the methods listed below, or aspects thereof, may be performed by at least one control unit. The term "control unit" may refer to a hardware device including a memory and a processor. The memory is configured to store program instructions, and the processor is specifically programmed to execute program instructions to perform one or more processes, which are further described below. Furthermore, it is understood that the methods below may be performed by a system including the control unit in combination with one or more additional components, as described in detail below.

[0026] Furthermore, the control unit of the present invention may be embodied as non-transitory computer-readable media on a computer-readable medium containing executable program instructions executed by a processor, a controller, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, CD-ROMs, magnetic tapes, floppy disks, USB flash drives, memory cards, and optical data storage devices. The computer-readable medium may also be distributed in network-coupled computer systems such that the computer-readable media is stored and executed in a distributed manner, e.g., by a telematics server or a Controller Area Network (CAN).

[0027] Referring now to embodiments of the present invention, the disclosed techniques optimize a vehicle torque map by tuning the torque map to a vehicle gearshift pattern. In particular, the torque map may be tuned to a downshift pattern (the torque map may also be tuned to an upshift pattern). Reshaping the torque map in each gear according to the shift pattern, as discussed herein, involves using 100% of the torque available to the engine at a given throttle position and speed (RPM) prior to a downshift, determined according to the vehicle's gearshift pattern. After the downshift, torque is calculated and generated such that there is a predetermined increase in engine power output.The predetermined increase in engine power output can be determined by the operator and can vary based on the application and / or operator preference. Optimizing the torque map in this way ensures that there is no sluggish response to any gear, as a power reserve is continuously maintained.

[0028] Fig. 4 shows an exemplary simplified procedure for matching a torque map to shift patterns. Procedure 400 may begin at step 405 and continue to step 410, where, as described in more detail herein, an iterative process is performed to reshape the vehicle torque map in each gear according to the vehicle's downshift pattern.

[0029] In step 410, several points on a vehicle downshift schedule are selected. For example, as in Fig. As shown in Figure 9, points on the downshift pattern should be selected before and after the intended downshift. The points can be taken from the higher gear shift line (pre-downshift) and from the lower gear shift line (post-downshift), as shown in Fig. 9 shown.

[0030] In step 415, a selected point from the higher gear in the downshift pattern is placed on the torque map of the corresponding gear (i.e., the higher gear), as shown in Fig. 9. The higher gear torque map is formed by plotting the selected point on the torque map such that 100% of the torque available to the engine is produced at the corresponding throttle pedal position, measured using an throttle position sensor (APS), and the engine speed (rpm) of the selected point before a downshift, determined according to the downshift schedule, takes place. For the purposes of the present invention, the torque that is 100% of the torque available to the engine at the corresponding throttle pedal position and speed (rpm) before the downshift may be referred to as the "first torque."

[0031] In step 420, a selected point from the lower gear in the downshift pattern is placed on the torque map of the corresponding gear (e.g., the lower gear), as shown in Fig. 9. The lower gear torque map is formed by plotting the selected point on the torque map such that a torque causing a predetermined increase in engine power output is produced after the downshift determined according to the downshift schedule takes place. That is, upon determining (e.g., determining) a first engine power output that occurs when the engine produces the first torque at a given accelerator pedal position and speed (rpm), a second engine power output equivalent to the first engine power output increased by a predetermined amount can be calculated.

[0032] The predetermined increase in engine power output may be determined by the operator and may vary based on the application and / or operator preference. Generally, a relatively higher increase in engine power output may be applied to a low-stroke piston engine, while a relatively lower increase in engine power output may be applied to a large-stroke piston engine. For example, the operator may define an increase of between about 5% to about 30% engine power output, depending on the operator's intentions and / or the specifications of the vehicle in question. In particular, the figures refer to a 10% increase in engine power output; however, this figure is provided primarily for demonstration purposes and should not be treated as limiting the scope of the claimed invention thereto.

[0033] Based on the calculated second engine power output, the torque resulting in the second engine power output, which may be a 10% increase in power in this particular example, is generated after the downshift occurs, given the corresponding accelerator pedal position and engine speed (rpm) of the selected point. For the purposes of the present invention, the torque resulting from the predetermined increase in power, given the corresponding accelerator pedal position and engine speed (rpm), after the downshift may be referred to as the "second torque."

[0034] In step 425, the torque mapping process may continue iteratively for all points on the downshift schedule until torque maps for the higher and lower gears, as well as the remaining gears, are formed. In some cases, it may be unnecessary to reshape the torque maps of the lower gears (e.g., first and second gears); therefore, it may only be necessary to reshape the torque maps of third gear and higher.

[0035] In greater detail, Fig. 5 is an exemplary diagrammatic representation of the downshift pattern-torque map relationship discussed herein. A torque map 520 may be matched to a downshift pattern 510 by selecting a point on the downshift pattern 510 and plotting the selected point in the torque map 520 based on whether the timing of the selected point is before or after the downshift. As shown in Fig. 5, in the case of a downshift from fourth to third gear, a point on a fourth gear downshift pattern line (e.g., pre-downshift) may be plotted in the torque map 520 such that 100% of the torque available to the engine is produced before the downshift occurs, given the accelerator pedal position (e.g., throttle opening or position) and engine speed (rpm) corresponding to the point selected in the downshift pattern 510. Then, a point on a third gear downshift pattern line (e.g., post-downshift) may be plotted in the torque map 520 such that torque is produced causing a predetermined increase in engine power output, given the accelerator pedal position and engine speed (rpm) corresponding to the point selected in the downshift pattern 510 after the downshift occurs.As explained above, the predetermined increase in engine power output can be determined by the operator / worker and may vary based on the application and / or operator / worker preference. Also, the operator / worker may specify the increase as being between approximately 5% and approximately 30%, or, in a specific example, approximately 10%, as shown in . Fig. 5, define.

[0036] As a result, a desired torque curve at a given throttle pedal position—40% in this particular example—is defined in the torque map 520 for a particular gear. The torque curve may be defined in the torque map 520 by performing the calculations described above in an iterative manner for multiple points on the downshift schedule 510 for all gears (or a subset of all gears). After the torque curve for each gear has been formed, a point on the curve for any given (APS, RPM) pair in any or all gears may have a torque value corresponding to either 100% of the torque available to the engine or a torque that causes a predetermined increase in engine power output, depending on whether the point is pre-downshift or post-downshift.

[0037] Furthermore, a constant power line is shown in the torque map 520. As is known in the art, power represents the product of torque multiplied by a speed (in this case: rpm). Therefore, with respect to power, torque and speed (rpm) are inversely proportional to each other. As shown in Fig. 5, the point on the third gear downshift pattern line (e.g., post-downshift) plotted in torque map 520 is on a positive side of the constant power line. This indicates a torque that causes an increase in engine power output above the point plotted in torque map 520 from the fourth gear downshift pattern line (e.g., pre-downshift).

[0038] Along these lines show Fig. 6A, Fig. 6B, Fig. 7A and Fig. 7B shows an exemplary process for optimizing the engine torque map according to the gear shift pattern. As shown in Fig. 6A and Fig. 6B, the torque map 520 for gear n may be formed for 100% of the torque available to the engine, requested prior to a downshift. Initially, a point on the downshift map (point A) may be selected for gear n. Each point on the downshift map 510 represents a (vehicle speed, APS) coordinate. In Fig. 6A corresponds to point A with a vehicle speed of x and an APS of y.

[0039] In Fig. 6B, the torque map 520 for gear n is shaped according to point A on the downshift schedule 510. In particular, the torque map 520 is shaped such that 100% of the torque available to the engine (e.g., first torque) is produced at point A (vehicle speed: x, APS: y). Therefore, by repeating this process in an iterative manner, as explained in step 425 in Fig. 4, a torque curve for APS y in gear n can be defined such that 100% of the available torque is generated at a given APS y and given speed (rpm) before a downshift occurs. This process can also be repeated for different accelerator pedal position values ​​in each gear to obtain a complete torque map for each gear, as shown in Fig. 8 is shown.

[0040] As shown in Fig. 7A and Fig. 7B, the torque map 520 for gear n-1 may be shaped for a torque that results in a predetermined increase in engine power output after the downshift. Initially, a point on the downshift map (point B) for gear n-1 may be selected. As discussed above, each point on the downshift map 510 represents a (vehicle speed, APS) coordinate. In Fig. 7A corresponds to point B with a vehicle speed of x and an APS of y+1.

[0041] In Fig. 7B, the torque map 520 for gear n is shaped according to point A on the downshift map 510. In particular, the torque map 520 is shaped such that a torque causing a predefined increase in engine power output (e.g., second torque) is generated at point B (vehicle speed: x, APS: y+1). In this regard, the operator / worker or a control unit (not shown), such as the vehicle's electronic control unit (ECU), can calculate the second torque by determining a first engine power output that occurs when the engine increases the torque at point A in gear n (e.g.,the first torque), calculating a second engine power output equivalent to the first engine power output increased by the predetermined increase in engine power output - defined by the worker - and finally deriving the second torque that causes the increase in engine power based on the calculated second engine power output (knowing that power is equal to the product of torque multiplied by the speed (rpm)).

[0042] Consequently, a torque curve for APS y+1 in gear n-1 may be defined such that a torque causing a predetermined increase in engine power output, as defined herein, is generated after the downshift occurs. Therefore, the engine power output corresponding to point B on the torque map 520 for gear n-1 is greater than the engine power output corresponding to point A on the torque map for gear n.

[0043] The calculations discussed above for deriving the second torque can be repeated in an iterative manner, as explained in step 425 in Fig. 4, for other gears and for different points along the downshift pattern 510 (e.g., different APS values) in each gear. In some cases, the torque map shaping process may be limited to a particular range of metrics. For example, shaping of the torque map 520 may be limited to an accelerator pedal position of between about 30% and about 70% depressed. Similarly, shaping of the torque map 520 may be limited to engine speeds (rpm) between about 500 rpm and about 4,000 rpm. Shaping of the torque map 520 may or may not be limited based on designer preferences, e.g., to save calculation time, to redefine vehicle torque delivery in specific circumstances, such as low, medium, and / or high throttle pressures, low, medium, and / or high engine speed (rpm), and so on.

[0044] Referring back to Fig. 4, the method 400 illustratively ends at step 430. The techniques by which the steps of the method 400 may be performed, as well as supplemental procedures and parameters, are described in detail above.

[0045] It should be noted that the steps described in Fig. 4 are primarily examples for illustrative purposes, and certain other steps may be included or excluded as desired. Furthermore, while a particular order of steps is shown, this arrangement is primarily exemplary, and any suitable arrangement of steps may be used without departing from the scope of the embodiment herein. Even the steps shown may be further modified in any suitable manner consistent with the scope of the present claims.

[0046] Now referring to Fig. 8 shows Fig. 8 shows an exemplary torque map formed according to the gear shift patterns. As shown in Fig. 8, a shaped torque map for fourth gear includes a plurality of torque lines corresponding to accelerator pedal position values ​​ranging from 5% to 100%. Using the shaped torque map, the engine can provide torque as an output based on inputs including an accelerator pedal position value and an engine speed (rpm). It should be noted that the slope, shape, length, position, and the like of the illustrated torque map lines in Fig. 8 are provided for demonstration purposes only and should not be treated as limiting the present invention. On the contrary, the Fig. The torque map shown in Figure 8 may be modified in any suitable manner according to the particular vehicle, the engine's capabilities, the designer's preferences, etc.

[0047] As explained above, the torque map shown in Fig. 8, can be formed by iteratively performing the torque calculations described herein for all gears (or a subset of gears) and for multiple throttle position values ​​in each gear. The result is a torque map that instructs an engine to provide a first torque that is 100% of the available torque for a given throttle position and speed (rpm) before a downshift, and a second torque that causes a predefined increase in engine power output after the downshift.

[0048] In the sculpted torque map, two points are shown in particular. First, a pre-downshift point is shown on the lower side of the constant power line. As explained above, the pre-downshift point represents an initial torque that is 100% of the torque available to the engine at a given throttle pedal position and engine speed (rpm) before a downshift (e.g., from fourth to third gear). As shown in Fig. 8, the pre-downshift point corresponds to 40% APS and approximately 1500 rpm.

[0049] Second, a post-downshift point is shown on the larger side of the constant power line. As explained above, the post-downshift point represents a second torque that causes a predefined increase in engine power output after a downshift (e.g., from fifth to fourth gear). The predefined increase in engine power output can be determined by the operator / worker and may vary based on the application and / or worker preference. Generally, a relatively higher increase in engine power output may be applied to a low-stroke piston engine, while a relatively lower increase in engine power output may be applied to a high-stroke piston engine. For example, the worker may define an increase of between approximately 5% to approximately 30% engine power output, depending on the operator's / worker's intentions and / or the specifications of the vehicle in question.As shown in . Fig. 8, the post-downshift point corresponds to 40% APS and approximately 2500 rpm. In this particular example, the engine power output corresponding to the post-downshift point is approximately 10% greater than the engine power output corresponding to the pre-downshift point.

[0050] Advantageously, the techniques for optimizing a vehicle torque map described herein utilize the vehicle's gearshift patterns to maintain a torque reserve for the driver and avoid sluggish acceleration or response due to torque saturation. This can improve vehicle drivability, enabling improved speed control (chassis dynamics), a linear feel during multi-gear kickdown, and the ability to shift hard into a desired gear. The resulting progressive acceleration during a downshift ensures a more predictable vehicle response to inputs from the accelerator pedal or gas pedal (for short, accelerator pedal).Additionally, with the optimized torque fields described herein, higher downshift lines can be used in the vehicle's shift patterns, consequently reducing shift "busyness."

[0051] While illustrative embodiments have been shown and described that provide for optimizing a vehicle torque map by matching the torque map to a gear shift pattern, it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the embodiments herein. For example, while torque map lines and gear shift lines are discussed herein and illustrated by the drawings (e.g., Fig.5-9), the indicated lines are provided primarily to demonstrate the disclosed embodiments and should not be treated as limiting the present invention to the indicated lines. That is, the slope, shape, length, position, and the like of the indicated torque map lines and gear shift lines are provided primarily for demonstration purposes and can be modified in accordance with a given vehicle, engine, or designer's preferences, as understood by one of ordinary skill in the art. Furthermore, the amount of power increase can be appropriately modified according to the designer's preferences; therefore, mention herein of a particular increase in engine power output should not be treated as limiting the claimed invention thereto.Therefore, the embodiments of the present invention may be modified in a suitable manner according to the scope of the present claims.

Claims

[1] A method comprising: Controlling torque generation by an internal combustion engine of a vehicle so that a first torque is generated in an n-th gear before a downshift, which is determined according to a gearshift pattern of the vehicle, wherein the first torque is 100% of the torque available to the engine at a given accelerator pedal position and a given engine speed (rpm) (S415); Calculating a second torque that causes a predefined increase in engine power output based on a first engine power output that occurs when the engine produces the first torque at the given accelerator pedal position and the given speed (rpm) (S420); and Controlling the torque generation by the engine so that the second torque is generated in an (n-1)th gear after the downshift. [2] The method of claim 1, wherein calculating the second torque comprises: Determining the first engine power output that occurs when the engine produces the first torque at the given accelerator pedal position and the given speed (rpm); Calculating a second engine power output equivalent to the first engine power output increased by the predetermined increase in engine power output; and Calculate the second torque based on the second engine power output. [3] The method of any preceding claim, wherein the given accelerator pedal position is between about 30% and 70% depressed, and the given engine speed (rpm) is between about 500 rpm and 4,000 rpm. [4] The method according to any one of the preceding claims, further comprising: Forming a torque line of a vehicle torque map for the n-th gear based on the first torque; and Forming a torque line from a vehicle torque map for the (n-1)th gear based on the second torque. [5] The method according to any one of the preceding claims, further comprising: Determining a plurality of first torques corresponding to a plurality of points on the gearshift pattern for the n-th gear, Forming a vehicle torque map including a plurality of torque lines for the n-th gear, wherein the plurality of torque lines are formed based on the plurality of determined first torques; Calculating a plurality of second torques corresponding to a plurality of points on the gear shift pattern for the (n-1)th gear; and Forming a vehicle torque map including a plurality of torque lines for the (n-1)th gear, wherein the plurality of torque lines are formed based on the plurality of calculated second torques. [6] The method of any preceding claim, wherein the predefined increase in engine power output is defined by a worker. [7] The method of any preceding claim, wherein the predefined increase in engine power output is an increase of between about 5% and 30%. [8] A system comprising: an internal combustion engine of a vehicle designed to generate torque that results in the movement of the vehicle; and a vehicle control unit designed to: Controlling torque generation by the engine so that a first torque is generated in an n-th gear before a downshift, which is determined according to a gearshift pattern of the vehicle, wherein the first torque is 100% of the torque available to the engine at a given accelerator pedal position and a given engine speed (rpm); Calculating a second torque that causes a predefined increase in engine power output based on a first engine power output that occurs when the engine produces the first torque at the given accelerator pedal position and the given speed (rpm); and Controlling the torque generation by the engine such that the second torque is generated in an (n-1)th gear after the downshift. [9] A non-transitory computer-readable medium containing program instructions for performing a method, the computer-readable medium comprising: Program instructions that control torque generation by an engine of a vehicle such that a first torque is generated in an n-th gear before a downshift determined according to a gearshift pattern of the vehicle, wherein the first torque is 100% of the torque available to the engine at a given accelerator pedal position and a given engine speed (rpm); Program instructions that calculate a second torque that causes a predefined increase in engine power output based on a first engine power output that occurs when the engine produces the first torque at the given accelerator pedal position and the given speed (rpm); and Program instructions that control the torque production by the engine such that the second torque is produced in an (n-1)th gear after the downshift.

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