Method for adjusting requested vehicle torque

Abstract

The present invention relates to a method for adjusting requested vehicle torque. A method for adjusting a powertrain torque output of a vehicle is described. In one example, the powertrain output torque of the vehicle is reduced by switching from a first curve of a transfer function to a second curve of the transfer function and then adjusting the powertrain output in response to the second curve of the transfer function.

Description

Technical Field

[0001] The present description relates to methods and systems for operating a powertrain system of a vehicle. The vehicle may include an internal combustion engine that can be automatically stopped and started. The methods and systems may be particularly useful for improving vehicle fuel economy and reducing the likelihood of automatically stopping the vehicle in a short period of time. Background Art

[0002] The vehicle's internal combustion engine may be automatically stopped during conditions when the vehicle speed is less than a threshold and when the driver demand torque is less than a threshold. The engine may be automatically stopped when the vehicle is decelerating or after the vehicle has come to a complete stop. During an automatic engine stop, fuel delivery to the engine may be terminated and engine rotation may be stopped. By terminating combustion and stopping the engine, fuel may be saved and the vehicle's mileage may be extended. However, if the vehicle's engine is stopped more frequently than desired, the vehicle's fuel economy may be reduced and vehicle engine starting components may deteriorate more rapidly. Summary of the invention

[0003] The inventors herein have recognized the above-mentioned problems and have developed a vehicle operation method, which includes: receiving vehicle road position data of a first vehicle and a second vehicle to a controller; adjusting the relationship between the accelerator pedal position and the transmission torque of the first vehicle in response to the distance between the first vehicle and the second vehicle; and adjusting the output of the transmission in response to the above-mentioned relationship.

[0004] By adjusting the relationship between the accelerator pedal position and the powertrain torque output in response to the distance between the first vehicle and the second vehicle, a technical effect of improving vehicle fuel economy and improving whether to automatically stop the engine of the powertrain can be provided. For example, if the distance between the first vehicle and the second vehicle is greater than a threshold distance, when the human vehicle driver steps on the accelerator pedal to the first position, the powertrain can generate a first torque greater than the second torque. However, when the distance between the first vehicle and the second vehicle is less than the first threshold, when the human vehicle driver steps on the accelerator pedal to the first position, the powertrain can generate a second torque less than the first torque. The lower second torque can help reduce vehicle acceleration when the vehicle may have to stop shortly after acceleration begins. In addition, by reducing vehicle acceleration for a given accelerator pedal position, the vehicle's engine can be stopped less frequently when the vehicle can be restarted shortly after stopping.

[0005] The present description may provide several advantages. Specifically, the present method may improve vehicle fuel economy by reducing vehicle acceleration and engine torque output for a given accelerator pedal position when the vehicle may be stopped shortly after the vehicle begins to accelerate. In addition, the present method may help avoid engine stops when the engine is about to be restarted shortly after stopping, thereby avoiding engine stops that may not improve vehicle fuel efficiency. In addition, the present method may reduce degradation of engine starting components by reducing less beneficial engine stops.

[0006] The above advantages and other advantages and features of the present description will be apparent in the following detailed description when taken alone or in conjunction with the accompanying drawings.

[0007] It should be understood that the above summary is provided to introduce some concepts in a simplified form, which are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the appended claims. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages mentioned above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram of an internal combustion engine that can be automatically stopped and started is shown.

[0009] Figure 2 Shown include Figure 1 Schematic diagram of a vehicle drive train or powertrain of an internal combustion engine shown in .

[0010] Figure 3 and Figure 4 A vehicle traveling on a road and the transfer functions for operating the vehicle are shown.

[0011] Figure 5 and Figure 6 A vehicle traveling on a road and a second transfer function for operating the vehicle are shown.

[0012] Figure 7 and Figure 8 Two example transfer functions for operating a vehicle in response to the position of an accelerator pedal are shown.

[0013] Fig. 9 An example method for operating a vehicle is shown. DETAILED DESCRIPTION

[0014] The present description relates to adjusting output torque of a vehicle driveline in response to an accelerator pedal position and a distance between a first vehicle and a second vehicle. Figure 1 An engine that can be automatically stopped and started is shown. The engine can be included in Figure 2 Alternatively, the engine may be included in a conventional vehicle driveline or a driveline having only an electric propulsion source. Figure 3-6 Example transfer functions for adjusting powertrain output in response to accelerator pedal position and vehicle position are shown. Figure 7 and Figure 8 Two different transfer functions for adjusting the powertrain output are shown. Fig. 9 Shown in.

[0015] refer to Figure 1 , including multiple cylinders ( Figure 1 Internal combustion engine 10 (one of the cylinders is shown in FIG. 1 ) is controlled by electronic engine controller 12. Engine 10 is composed of cylinder head 35 and cylinder block 33, which includes combustion chamber 30 and cylinder wall 32. Piston 36 is positioned therein and reciprocates through connection with crankshaft 40. Flywheel 97 and ring gear 99 are coupled to crankshaft 40. Starter 96 (e.g., a low voltage (operating at a voltage less than 30 volts) motor) includes pinion shaft 98 and pinion 95. Pinion shaft 98 can selectively advance pinion 95 to engage ring gear 99. Starter 96 can be mounted directly to the front of the engine or the rear of the engine. In some examples, starter 96 can selectively supply torque to crankshaft 40 via a belt or chain. In one example, starter 96 is in a basic state when not engaged to the engine crankshaft. Combustion chamber 30 is shown as being connected to intake manifold 44 and exhaust manifold 48 via corresponding intake valve 52 and exhaust valve 54. Each intake valve and exhaust valve may be operated by an intake cam 51 and an exhaust cam 53. The position of intake cam 51 may be determined by an intake cam sensor 55. The position of exhaust cam 53 may be determined by an exhaust cam sensor 57. Intake valve 52 may be selectively activated and deactivated by valve activation device 59. Exhaust valve 54 may be selectively activated and deactivated by valve activation device 58. Valve activation devices 58 and 59 may be electromechanical devices.

[0016] Fuel injector 66 is shown positioned to inject fuel directly into cylinder 30, which is known to those skilled in the art as direct injection. Fuel injector 66 delivers liquid fuel in proportion to the pulse width from controller 12. Fuel is delivered to fuel injector 66 by a fuel system (not shown) including a fuel tank, a fuel pump, and a fuel rail. In one example, a high pressure dual stage fuel system may be used to generate higher fuel pressures.

[0017] In addition, intake manifold 44 is shown as being in communication with turbocharger compressor 162 and engine intake 42. In other examples, compressor 162 may be a supercharger compressor. Shaft 161 mechanically couples turbocharger turbine 164 to turbocharger compressor 162. Optional electronic throttle 62 adjusts the position of throttle plate 64 to control air flow from compressor 162 to intake manifold 44. Since the inlet of throttle 62 is in boost chamber 45, the pressure in boost chamber 45 may be referred to as throttle inlet pressure. The throttle outlet is in intake manifold 44. In some examples, throttle 62 and throttle plate 64 may be positioned between intake valve 52 and intake manifold 44 so that throttle 62 is a port throttle. Compressor recirculation valve 47 may be selectively adjusted to a plurality of positions between fully open and fully closed. Wastegate 163 may be adjusted by controller 12 to allow exhaust to selectively bypass turbine 164, thereby controlling the speed of compressor 162. Air filter 43 cleans air entering engine intake 42.

[0018] Distributorless ignition system 88 provides an ignition spark to combustion chamber 30 via spark plug 92 in response to controller 12. Universal Exhaust Gas Oxygen (UEGO) sensor 126 is shown coupled to exhaust manifold 48 upstream of catalytic converter 70. Alternatively, a two-state exhaust gas oxygen sensor may be substituted for UEGO sensor 126.

[0019] In one example, converter 70 may include multiple catalyst bricks. In another example, multiple emission control devices may be used, each with multiple bricks. In one example, converter 70 may be a three-way type catalyst.

[0020] exist Figure 1The controller 12 is shown as a conventional microcomputer including a microprocessor unit (CPU) 102, input / output ports (I / O) 104, read-only memory (ROM) 106 (e.g., non-volatile memory), random access memory (RAM) 108, keep-alive memory (KAM) 110, and a conventional data bus. Controller 12 is shown receiving various signals from sensors coupled to engine 10, including, in addition to those previously discussed, engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling jacket 114; position sensor 134 coupled to accelerator pedal 130 for sensing force applied by foot 132; position sensor 154 coupled to brake pedal 150 for sensing force applied by foot 152, a measurement of engine manifold pressure (MAP) from pressure sensor 122 coupled to intake manifold 44; an engine position sensor from Hall effect sensor 118 sensing position of crankshaft 40; a measurement of air mass entering the engine from sensor 120; and a measurement of throttle position from sensor 68. Barometric pressure may also be sensed (sensor not shown) for processing by controller 12. In a preferred aspect of the present description, engine position sensor 118 generates a predetermined number of equally spaced pulses for every rotation of the crankshaft (from which engine speed (RPM) can be determined).

[0021] During operation, each cylinder within engine 10 typically undergoes a four stroke cycle: the cycle includes an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. During the intake stroke, generally, exhaust valve 54 is closed and intake valve 52 is opened. Air is introduced into combustion chamber 30 via intake manifold 44, and piston 36 moves to the bottom of the cylinder so as to increase the volume within combustion chamber 30. The position at which piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g., when combustion chamber 30 is at its largest volume) is typically referred to by those of skill in the art as bottom dead center (BDC).

[0022] During the compression stroke, intake valve 52 and exhaust valve 54 are closed. Piston 36 moves toward the cylinder head so as to compress the air within combustion chamber 30. The point at which piston 36 is at the end of its stroke and closest to the cylinder head (e.g. when combustion chamber 30 is at its smallest volume) is typically referred to by those of skill in the art as top dead center (TDC). In a process hereinafter referred to as injection, fuel is introduced into the combustion chamber. In a process hereinafter referred to as ignition, the injected fuel is ignited by known ignition means (e.g., spark plug 92), resulting in combustion.

[0023] During the expansion stroke, the expanding gases push piston 36 back to BDC. Crankshaft 40 converts the piston motion into rotational torque of the rotating shaft. Finally, during the exhaust stroke, exhaust valve 54 opens to release the combusted air-fuel mixture to exhaust manifold 48 and the piston returns to TDC. Note that the above is shown only as an example, and the intake and exhaust valve opening and / or closing timings may be varied, such as to provide positive or negative valve overlap, delayed intake valve closing, or a variety of other examples.

[0024] Reference now Figure 2 , shows an example of a transmission system 200. The transmission system 200 includes Figure 1 204. The engine 10 and torque drivers (e.g., throttle, fuel injector, camshaft, etc.) 204 described in FIG. The engine 10 provides torque to the planetary gear set 202, and the generator 203 can be operated in a speed control mode to control the engine torque delivery to the single ratio transmission system 210. The output from the generator 203 provides electrical energy to the energy storage device 275 and the electric machine (e.g., motor / generator) 206. When the engine 10 is not operating, the energy storage device 275 can supply power to the motor 206 through the variable voltage controller 271. The energy storage device can be a battery, a capacitor, or other energy storage device, and the energy storage device 275 can be selectively connected to the fixed power grid 299 via the jack 297 and the voltage converter 298 to recharge the energy storage device 275.

[0025] The electric machine 206 can operate as a motor or a generator. During regenerative braking, charging can be provided when the electric machine 206 operates in generator mode. Alternatively, the electric machine 206 can provide torque to the wheels 216 and rotate the engine 10 for starting or diagnostics. In pure electric mode, the electric machine 206 can propel the vehicle 250 without the help of the engine 10. In engine-only mode, the engine 10 can propel the vehicle 250 without the help of the electric machine 206. The torque from the engine 10 and the electric machine 206 can be combined in the single-ratio transmission system 10 to provide torque to the wheels 216 through a mechanical power path. The controller 12 controls the operation of the engine 10, the generator 204, and the electric machine 206 to adjust the power supplied to the wheels 216.

[0026] The vehicle range sensor 237 may include light detection and ranging (LIDAR), radar, sound waves, and / or other known range and object sensors. Other vehicles located in front of the vehicle 250 (also referred to herein as the first vehicle) and in the path of the vehicle 250 can sense the distance of the vehicle 250 through the vehicle range sensor 237 and report to the controller 12. In addition, the controller 12 can determine the location of the vehicle 250 through the global positioning system (GPS) 235. Satellites (not shown) orbiting the earth provide radio signals processed by the GPS235 to provide the location of the vehicle 250. The vehicle 250 can also communicate with other vehicles or via a remote communication network through a radio frequency (RF) transmitter and receiver 236. The vehicle 250 can send data to and receive data from a remote transmitter / receiver 255, which is part of a network 256 (e.g., a cloud computing navigation assistance network).

[0027] therefore, Figure 1 and Figure 2 A system of the invention provides a vehicle system comprising: an engine; a vehicle position sensor; an accelerator pedal; and a controller including executable instructions stored in a non-transitory memory, the executable instructions being used to reduce the driveline torque delivered by the engine or a second propulsion source of the first vehicle in response to a constant output of the accelerator pedal and a decreasing distance between the first vehicle and the second vehicle indicated by the vehicle position sensor. The vehicle system further comprises additional instructions for adjusting the relationship between the position of the accelerator pedal of the first vehicle and the driveline torque in response to an amount of time that the nearest second vehicle and the third vehicle are stopped and an amount of time that the nearest second vehicle and the third vehicle are moving without stopping when the second vehicle and the third vehicle are traveling in a train of at least two vehicles. The vehicle system includes wherein the second propulsion source is an electric machine. The vehicle system further comprises additional instructions for increasing the driveline torque delivered by the engine or the second propulsion source of the first vehicle in response to a constant output of the accelerator pedal and a decreasing distance between the first vehicle and the second vehicle indicated by the vehicle position sensor.

[0028] Reference now Figure 3 , showing two vehicles traveling on a road. The road 300 includes a first vehicle 250 and a second vehicle 302 traveling in a first lane 301 of the road 300. When the second vehicle 302 is traveling in the path of the first vehicle 250 (e.g., the same lane) and there is no intermediate vehicle between the first vehicle 250 and the second vehicle 302, the vehicle range sensor 237 reports a distance D1 between the first vehicle 250 and the second vehicle 302. The distance D1 may be updated at a predetermined rate (e.g., every 100 milliseconds) and provided to the Figure 1. In addition, the sensor 237 may have an effective vehicle detection distance D1, such as 700 meters. If the second vehicle 302 travels in the same lane of the first vehicle 250 in a range exceeding the effective vehicle detection distance D1 of the sensor 237 without any intervening vehicles, the sensor 237 does not indicate the presence of the second vehicle 302. Further, if the first lane 301 is curved, the second vehicle 302 may or may not be detected by the sensor 237 depending on the distance D1 between the first vehicle 250 and the second vehicle 302 and the curvature of the first lane 301. In this example, the distance D1 may be a long distance greater than the first threshold distance.

[0029] Reference now Figure 4 , shows an example transfer function or relationship that relates accelerator pedal position to driver demand torque. Transfer function 400 includes a vertical axis and a horizontal axis. The vertical axis represents the driver demand torque (e.g., the torque requested by the human driver at the transmission input shaft), and the driver demand torque increases in the direction of the vertical axis arrow. A value of zero represents zero driver demand torque, and a value of 100 represents 100% of the available driver demand torque. For example, if the powertrain includes a sole propulsion source (e.g., an engine) that can output a maximum torque of 300 Newton-meters (Nm) at the current engine speed (e.g., available powertrain torque), 100% of the driver demand torque requests 300N-m from the powertrain or requests all available powertrain torque. If the powertrain includes the same engine and an electric motor that can output a maximum torque of 50N-m at the current engine speed, 100% of the driver demand torque requests 350N-m from the powertrain.

[0030] Line 402 describes the relationship between accelerator pedal position and driver demand torque. For each percentage increase in accelerator pedal position, the driver demand torque increases by the same percentage. For example, for an accelerator pedal depressed to a 50% position, the driver demand torque is 50% of the available powertrain torque. Therefore, there is a linear relationship between accelerator pedal position and driver demand torque. The driver demand torque can be provided by adjusting the engine torque and / or the motor torque to provide the driver demand torque. When Figure 3This type of relationship may be desirable for vehicle operating conditions of the vehicle 250 when there is a large distance (e.g., greater than a first threshold distance) D1 between the first vehicle 250 and the second vehicle 302 as shown. Therefore, in response to the distance D1 being greater than the first threshold distance (e.g., 150 meters), the accelerator pedal of the first vehicle 250 may provide a driver demand torque corresponding to the relationship provided by the line 402 of the transfer function 400. By providing the driver demand torque in response to the transfer function 400, the vehicle 250 may accelerate at a higher rate when other vehicles are moving away from the vehicle 250, thereby providing the desired vehicle performance.

[0031] Reference now Figure 5 , showing three vehicles traveling on a road. The road 300 includes a first vehicle 250, a second vehicle 302, and a third vehicle 502 traveling in a first lane 31 of the road 300. When the second vehicle 302 is traveling in the path of the first vehicle 250 (e.g., the same lane) and there are no intermediate vehicles between the first vehicle 250 and the second vehicle 302, the vehicle range sensor 237 reports a distance D2 between the first vehicle 250 and the second vehicle 302. In this example, the distance D2 is much smaller than Figure 3 Therefore, the distance D2 may be a short distance less than the first threshold distance.

[0032] The second vehicle 302 is separated from the third vehicle 502 by a distance D3. The distance D3 may be reported to the first vehicle 250 by the second vehicle 302 sending data to the remote transmitter / receiver 255 and the network 256 or directly to the first vehicle 250. Alternatively, the sensors 509 in the road 300 may provide the first vehicle 250 with the locations of vehicles traveling on the road 300. In addition, the third vehicle 502 and the second vehicle 302 may send their respective speeds, positions, acceleration rates, and response delay times (e.g., if the second vehicle 302 and the third vehicle 502 stop and then begin to move, the time required for the second vehicle 302 to move in response to the movement of the third vehicle 502 is the response delay time) to the transmitter / receiver 255 or directly to the first vehicle 250 so that the first vehicle 250 may change the driveline torque in response to the distance D2, the distance D3, the speeds and accelerations of the second vehicle 302 and the third vehicle 502, the response delay times of the second vehicle 302 and the third vehicle 502, the amount of time that the second vehicle 302 and the third vehicle 502 stopped during their most recent vehicle stop, the amount of time that the second vehicle 302 and the third vehicle 502 moved and did not stop during their most recent vehicle movement, and the accelerator pedal position of the first vehicle 250. The driveline torque of the first vehicle 250 may be adjusted by adjusting the curve of the transfer function, switching between different transfer functions, or adjusting a filter factor applied to the accelerator pedal position as described in more detail herein. The second vehicle 302 and the third vehicle 502 may transmit their respective vehicle data via transmitters 505 and 502 .

[0033] Reference now Figure 6 , shows an example transfer function or relationship that relates accelerator pedal position to driver demand torque. Transfer function 400 includes Figure 4 However, in this example, transfer function 400 includes curve 610 that provides a lower driver demand torque for accelerator pedal values ​​greater than zero and less than 100 than line 402 .

[0034] Curve 610 depicts the relationship between the accelerator pedal position and the driver demand torque when the first vehicle 250 is within a fifth threshold distance D2 of the second vehicle 302. Figure 7The relationship of the second, third, and fourth threshold distances is illustrated in FIG. For each percentage increase in accelerator pedal position, curve 610 provides an increase in driver demand torque of less than one percent. For example, for an accelerator pedal depressed to a 50% position, the driver demand torque is approximately 15% of the available powertrain torque. Thus, when the distance between the first vehicle 250 and the second vehicle 302 is less than the threshold distance D2 (e.g., 15 meters), the driver of the vehicle may depress the accelerator pedal and a much lower driver demand torque may be output via transfer function 400. As shown in FIG. Figure 5 As shown, when there is a small distance D2 between the first vehicle 250 and the second vehicle 302 (e.g., less than a second threshold distance), providing a driver demand torque according to curve 610 (relationship between accelerator pedal position and driver demand torque) may be desirable for the vehicle operating conditions of the first vehicle 250. Therefore, in response to the distance D2 being less than the threshold distance (e.g., 15 meters), the accelerator pedal of the first vehicle 250 may provide a driver demand torque corresponding to the relationship provided by curve 610 of the transfer function 400. By providing the driver demand torque in response to the transfer function 400, when other vehicles are close to the vehicle 250 and in the path of the vehicle 250, the vehicle 250 may accelerate more slowly for the same accelerator pedal position progression than when the vehicles are farther apart, so that the engine operating time may be increased during stopping and driving, so that the vehicle 250 is not frequently stopped and restarted in a short time thereafter (e.g., within 5 seconds).

[0035] Reference now Figure 7 , shows an example transfer function 400 including a plurality of straight lines or curves representing the relationship between the vehicle accelerator pedal position and the driver demand torque. The transfer function 400 includes Figure 4 However, in this example, the transfer function 400 includes a plurality of curves, including the straight line 402 and the curve 610. For when the first vehicle (e.g., the vehicle providing the basis for the accelerator pedal position) and the second vehicle (e.g., Figure 3For a situation when the distance between the first vehicle and the second vehicle (shown in FIG. 1 ) is greater than a first threshold distance (e.g., 150 meters), straight line 402 associates the accelerator pedal position with the driver demand torque. For a situation when the distance between the first vehicle and the second vehicle is equal to a second threshold distance (e.g., 110 meters), curve 704 associates the accelerator pedal position with the driver demand torque. For a situation when the distance between the first vehicle and the second vehicle is equal to a third threshold distance (e.g., 85 meters), curve 706 associates the accelerator pedal position with the driver demand torque. For a situation when the distance between the first vehicle and the second vehicle is equal to a fourth threshold distance (e.g., 50 meters), curve 708 associates the accelerator pedal position with the driver demand torque. For a situation when the distance between the first vehicle and the second vehicle is equal to a fifth threshold distance (e.g., 15 meters), curve 610 associates the accelerator pedal position with the driver demand torque. If the distance between the first vehicle and the second vehicle represents a distance between the distances corresponding to the curves, interpolation can be performed between the curves to provide the desired driver demand torque. For example, if the distance between the first vehicle and the second vehicle is 130, the driver demand torque is determined in response to the accelerator pedal position by interpolating between the line 402 and the curve 704. Thus, the transfer function 400 may be represented by a set of curves, and they may be stored in the controller memory as one or more functions or in the form of a lookup table. The curves may be determined empirically while driving the vehicle in traffic or on a test track.

[0036] Transfer function 400 shows the accelerator pedal at the 50% position (e.g., the accelerator pedal is depressed half of its total travel distance). If the distance that the first vehicle follows the second vehicle is greater than the distance corresponding to line 402, the driver demand torque is v5, or approximately 50%. If the distance that the first vehicle follows the second vehicle is equal to the distance corresponding to curve 704, the driver demand torque is v4, or approximately 40%. If the distance that the first vehicle follows the second vehicle is equal to the distance corresponding to curve 706, the driver demand torque is v3, or approximately 30%. If the distance that the first vehicle follows the second vehicle is equal to the distance corresponding to curve 708, the driver demand torque is v2, or approximately 20%. If the distance that the first vehicle follows the second vehicle is equal to the distance corresponding to curve 610, the driver demand torque is v1, or approximately 10%.

[0037] Note that in this example, line 402, curves 704-708, and curve 610 all provide 100% driver demand torque at 100% accelerator depression. Thus, as the distance between the first vehicle and the second vehicle decreases, the driveline torque decreases at some accelerator pedal positions; however, if the human driver fully depresses the accelerator pedal, 100% driver demand torque is available.

[0038] Reference now Figure 8 , shows an alternative example transfer function 800 including a plurality of straight lines or curves representing the relationship between the vehicle accelerator pedal position and the driver demand torque. The transfer function 800 includes Figure 4 The transfer function 800 includes a plurality of curves numbered 802-810. For a first vehicle (e.g., a vehicle providing an accelerator pedal position basis) and a second vehicle (e.g., a vehicle providing an accelerator pedal position basis) and a second vehicle (e.g., a vehicle providing an accelerator pedal position basis) when the transfer function 800 is described in detail. Figure 3 For a case where the distance between the first vehicle and the second vehicle (shown in FIG. 1 ) is greater than a first threshold distance (e.g., 150 meters), straight line 802 associates the accelerator pedal position with the driver demand torque. For a case where the distance between the first vehicle and the second vehicle is equal to a second threshold distance (e.g., 110 meters), curve 804 associates the accelerator pedal position with the driver demand torque. For a case where the distance between the first vehicle and the second vehicle is equal to a third threshold distance (e.g., 85 meters), curve 806 associates the accelerator pedal position with the driver demand torque. For a case where the distance between the first vehicle and the second vehicle is equal to a fourth threshold distance (e.g., 50 meters), curve 808 associates the accelerator pedal position with the driver demand torque. For a case where the distance between the first vehicle and the second vehicle is equal to a fifth threshold distance (e.g., 15 meters), curve 810 associates the accelerator pedal position with the driver demand torque. If the distance between the first vehicle and the second vehicle represents a distance between the distances corresponding to the curves, interpolation can be performed between the curves to provide the desired driver demand torque. Thus, the transfer function 800 may be represented by a set of curves, and which may be stored in the controller memory as one or more functions or in the form of a look-up table.The curves may be determined empirically while driving the vehicle in traffic or on a test track.

[0039] In this example, only curve 802 reaches 100% of the driver demand torque. When the accelerator pedal position is stepped on or pressed to 100%, curves 804-810 do not extend to 100% of the driver demand torque. Therefore, when the distance between the first vehicle and the second vehicle corresponds to the distance represented by curves 804-810, the maximum driver demand torque is limited or constrained. Therefore, not only is the driver demand torque provided by curves 804-810 reduced compared to the driver demand torque provided by curve 802, the maximum driver demand torque is also limited. Moreover, each of curves 804-810 provides a different maximum driver demand torque or upper threshold torque limit. These curves can be used to further improve vehicle fuel economy and reduce frequent engine restarts.

[0040] Reference now Fig. 9 , a method for operating a vehicle is shown. At least some portions of method 900 may be implemented as executable controller instructions stored in a non-transitory memory. Method 900 may be implemented with Figure 1 and Figure 2 Additionally, portions of method 900 may be actions taken in the physical world to transform an operating state of an actuator or device. Fig. 9 The method may be incorporated as executable instructions stored in a non-transitory memory. Figure 1 and Figure 2 in the system.

[0041] At 902, method 902 determines vehicle operating conditions, including but not limited to the distance from the current vehicle (e.g., the first vehicle) to the second vehicle in the vehicle's travel path, the speed and acceleration of the vehicles in the current vehicle path, the accelerator pedal position, the vehicle speed, the amount of time other vehicles in the current vehicle path stopped or stopped for the most recent stop of other vehicles, the amount of time other vehicles in the current vehicle path are moving or moving and not stopped for the most recent time other vehicles moved or are moving, and the acceleration of other vehicles. After determining the vehicle operating conditions, method 900 proceeds to 904.

[0042] At 904, method 900 determines whether the second vehicle is in the path of the current vehicle (e.g., the first vehicle) and within a first predetermined distance of the current vehicle. Method 900 may determine that the second vehicle is in the path of the current vehicle and within a predetermined distance of the current vehicle in response to the output of one or more range sensing devices. If method 900 determines that the second vehicle is in the path of the current vehicle and within a first predetermined distance of the current vehicle (e.g., the maximum distance or another predetermined distance that the range sensing device can sense the vehicle), if the answer is "yes", then method 900 proceeds to 906. Otherwise, the answer is "no", then method 900 proceeds to 920.

[0043] At 920, if the driver demand torque has decreased in response to the accelerator pedal position, method 900 adjusts the driver demand torque or the powertrain torque commanded when the accelerator pedal is depressed in response to the accelerator pedal position. Specifically, when the accelerator pedal is not depressed, method 900 may adjust the driver demand torque or the powertrain output torque commanded when the accelerator pedal is depressed in response to the accelerator pedal position according to one of the following steps.

[0044] If method 900 is performed according to the method including Figure 7 and Figure 8, method 900 adjusts the driver demand torque in response to a curve or line that provides the maximum amount of powertrain output torque for each accelerator pedal position between the accelerator pedal not depressed and the accelerator pedal depressed. For example, if method 900 recently responded to Figure 7 The curve 704 of the transfer function 400 shown commands the driver demand torque, and the method 900 commands the driver demand torque in response to the curve 402. Therefore, for positions other than the position where the accelerator pedal is not depressed, the driver demand torque increases for a given accelerator pedal position. Therefore, the method 900 changes the driver demand torque by changing between curves that describe the driver demand torque as a function of the accelerator pedal position.

[0045] If method 900 adjusts the driver demand torque according to a transfer function represented as a polynomial that is a function of accelerator pedal position, the coefficients of the polynomial are adjusted so that for each percentage increase in accelerator pedal position, the driver demand torque increases by the same percentage. Thus, if the coefficients of the polynomial describing the driver demand torque provide a transfer function that follows Figure 7 The curve 704 is similar to the curve of the driver's demand torque, then according to Figure 4 Line 402 adjusts the coefficients of the polynomial to provide the driver demand torque.

[0046] If method 900 is based on a single straight line (e.g., Figure 4 The method 900 adjusts the filter factor of the low pass filter to reduce the amount of time required for the step response input to the accelerator pedal to reach its final value of 63.2% from the step increase to the accelerator pedal. Therefore, by modifying the filter constant, the driver demand torque can reach its final value more quickly.

[0047] After adjusting the driver demand torque or powertrain torque commanded in response to a tip-in in response to accelerator pedal position when the driver demand torque has decreased in response to accelerator pedal position, method 900 proceeds to exit. If the driver demand torque has not decreased in response to accelerator pedal position, method 900 proceeds to exit and does not adjust the relationship between accelerator pedal position and the commanded driver demand torque or powertrain torque.

[0048] At 906, method 900 adjusts the driver demand torque or powertrain torque commanded when tipping in response to the accelerator pedal position. Specifically, method 900 adjusts the commanded torque from a baseline torque or commanded torque (e.g., Figure 4 The straight line 402 represents the relationship) which reduces the driver demand torque or the powertrain output torque.

[0049] In one example, method 900 includes Figure 7 and Figure 8 The transfer functions of the multiple curves shown adjust the driver demand torque. Method 900 is responsive to generating or providing a reference line or curve (e.g., Figure 4 The straight line 402) of the driver demand torque or the transmission output torque is reduced compared to the curve or straight line of the reduced driver demand torque or the transmission output torque. Specifically, it can be as follows Figure 7 The different distances between the first vehicle shown (e.g., the current vehicle including multiple curves) and a second vehicle in the first vehicle's travel path provide multiple curves representing the driver demand torque for a given accelerator pedal position. As the distance between the first vehicle and the second vehicle changes, different curves are the basis for converting the accelerator pedal position into the driver demand torque. For example, if the first vehicle is approaching the second vehicle (e.g., if the distance between the first vehicle and the second vehicle is decreasing), the method 900 transitions from determining the driver demand torque by applying the straight line 402 to determining the driver demand torque by applying the curve 704. Then, as the first vehicle moves closer to the second vehicle, the method 900 transitions from determining the driver demand torque by applying the curve 704 to determining the driver demand torque by applying the curve 706. Thus, the method 900 changes from determining the driver demand torque using one curve to determining the driver demand torque using another curve. The curve or straight line that is used as the basis for determining the driver demand torque is selected based on the distance between the first vehicle and the second vehicle. If the distance between the first vehicle and the second vehicle increases, the method 900 selects a straight line or curve that is closer to the baseline (e.g., Figure 4For distances that do not directly correspond to curves, method 900 interpolates between the curves. For example, if the baseline straight line representing the driver demand torque provides 50% of the available driver demand torque (which corresponds to 50% of the available powertrain torque) based on the accelerator pedal position when the accelerator pedal is depressed to 50% for a distance between the first vehicle and the second vehicle greater than 150 meters, and if the curve representing the driver demand torque provides 35% of the available driver demand torque (which corresponds to 35% of the available powertrain torque) based on the accelerator pedal position when the accelerator pedal is depressed to 50% for a distance between the first vehicle and the second vehicle equal to 110 meters, method 900 interpolates between the baseline straight line and the curve for a distance equal to 130 meters to determine a driver demand torque that is 42.5% of the available driver demand torque.

[0050] In another example, the method 900 is based on a formula expressed as a polynomial (eg, Driver_demand=C0+C1accped+C3accped 2 +C4accped 3 , where Driver_demand is the driver demand torque, C0-C4 are predetermined coefficients, and accped is the accelerator pedal position). A baseline set of coefficients is provided for distances between the first vehicle and the second vehicle that are greater than a threshold distance (e.g., 150 meters), and then the coefficients C0-C4 are adjusted so that for a given accelerator pedal input when the distance between the first vehicle and the second vehicle decreases, the driver demand torque is reduced. If the distance between the first vehicle and the second vehicle increases to greater than the threshold distance, the coefficients C0-C4 are adjusted back to the baseline coefficients. In this way, the driver demand torque can be adjusted based on the accelerator pedal position and the distance between the first vehicle and the second vehicle.

[0051] In yet another example, method 900 is based on a single straight line (eg, Figure 4The driver demand torque is adjusted by a transfer function of a straight line 402) with a low pass output (e.g., y(i)=α1·x(i)+(1-α1)·y(i-1), where y is the filter output, i is the number of samples, x is the filter input, and α1 is the filter factor). The low pass filter can receive an accelerator pedal input and it can provide a filtered accelerator pedal position to the transfer function, which then outputs the driver demand torque. Alternatively, the accelerator pedal position can be input to the transfer function and the transfer function outputs the driver demand torque. The driver demand torque is then input to the low pass filter and the output of the low pass filter is the driver demand torque, which is the basis for adjusting the powertrain torque. By adjusting the filter factor, the time constant of the low pass filter can be increased so that it takes longer for the driver demand torque to reach its final value, thereby slowing down the powertrain torque generation, so that it takes longer for the vehicle to accelerate so that the vehicle travel can be increased during parking and driving. The filter is only applicable to increasing accelerator pedal position, not decreasing accelerator pedal position.

[0052] Method 900 may select to adjust the driver demand torque according to one of the three methods described above or methods that provide similar functionality based on vehicle configuration. Method 900 proceeds to 908 .

[0053] At 908, method 900 receives data about vehicles within a predetermined distance of the current vehicle. In one example, method 900 receives traffic data of vehicles in the path of the current vehicle via radio frequency (e.g., wireless). The data may be sent by other vehicles or over a network. The data received about other vehicles in the path of the current vehicle may include, but is not limited to, the current acceleration of the vehicle, the amount of time each other vehicle has stopped during its respective most recent stop, the amount of time each other vehicle has moved during its respective most recent movement event (including the time the vehicle has moved if the vehicle is currently moving), and the location of vehicles within the predetermined distance of the current vehicle. Method 900 proceeds to 910.

[0054] At 910, method 900 determines whether the current vehicle (e.g., the first vehicle) is in a queue of multiple vehicles, including the second vehicle in the path of the first vehicle and the second vehicle. Method 900 determines whether a team of vehicles exists in front of the second vehicle and in the path of the first vehicle and the second vehicle based on the vehicle position information collected at 908. If method 900 determines whether a team of vehicles exists in front of the second vehicle and within a predetermined range (e.g., 200 meters) of the first vehicle, the answer is "yes" and method 900 proceeds to 912. Otherwise, the answer is "no" and method 900 proceeds to exit. In addition, if the answer is "no", method 900 can command the powertrain to provide the driver's demand torque by adjusting the engine and motor torque actuators (e.g., engine throttle, inverter output, etc.).

[0055] At 912, method 900 determines whether one or more vehicles in the current vehicle path have moved for less than a first threshold amount of time or whether one or more vehicles in the current vehicle path have stopped for more than a second threshold amount of time. Method 900 may be determined by data provided by other vehicles in the convoy. If method 700 determines that one or more vehicles in the current vehicle path have moved for less than a first threshold amount of time or one or more vehicles in the current vehicle path have stopped for more than a second threshold amount of time, the answer is "yes" and method 900 proceeds to 914. Otherwise, method 900 proceeds to exit.

[0056] For example, if the time that the vehicle in the path of the first vehicle and ahead of the second vehicle has been moving is less than a first threshold amount of time of the most recent time that the vehicle has been moving, then the answer is "yes" and method 900 proceeds to 914. It should be noted that if the vehicle is currently moving and the amount of time that the vehicle has currently been moving is less than the first threshold, then the amount of time that the vehicle spent moving during the previous time that the vehicle was moving is the basis for determining whether the time that the vehicle has been moving is less than the threshold amount of time.

[0057] In another example, if the time that the vehicle in the path of the first vehicle and ahead of the second vehicle has been stopped is greater than a second threshold amount of time at the most recent time that the vehicle has been stopped, then the answer is "yes" and method 900 proceeds to 914. It should be noted that if the vehicle is currently stopped and the amount of time that the vehicle has been stopped is less than the second threshold, then the amount of time that the vehicle spent stopped during the last time that the vehicle was stopped is the basis for determining whether the time that the vehicle has been stopped is greater than the threshold amount of time.

[0058] The amount of time that the vehicle is stopped combined with the amount of time that the vehicle is moving can indicate how often the vehicle is stopped and started in a convoy of vehicles. If the amount of time that the vehicle is moving is shorter, it may be desirable to reduce the driver demand torque for a given accelerator pedal position so that the vehicle can be started longer to extend the amount of time between vehicle stops, thereby preventing shorter and more frequent engine stops. On the other hand, if the amount of time that the vehicle is stopped is shorter, it may be desirable to reduce the driver demand torque for a given accelerator pedal position so that the vehicle can be started longer to extend the amount of time between vehicle stops, thereby preventing shorter and more frequent engine stops.

[0059] The method 900 may also determine a distance between the second vehicle and a third vehicle that is directly located in the path of the second vehicle without intervening vehicles. The distance between the second vehicle and the third vehicle may be provided in data received from the second vehicle and provided to the first vehicle, or provided by data provided by the second vehicle and the third vehicle.

[0060] At 914, method 900 further reduces the driver demand torque for a given accelerator pedal position. In the above-described method of adjusting the driver demand torque, the driver demand torque is adjusted in response to the distance between the first vehicle and the second vehicle. Method 900 may provide an adjustment to the distance between the first vehicle and the second vehicle to compensate for the relative movement of the vehicles in a convoy of vehicles, so that one of the same methods described above can determine the driver demand torque. In addition, method 900 may provide a further adjustment to the distance between the first vehicle and the second vehicle based on the distance between the second vehicle and the third vehicle. For example, if the amount of time that a vehicle in a convoy of vehicles in front of the second vehicle is stopped is greater than a first threshold, and if the distance between the first vehicle and the second vehicle is 150 meters, method 900 may modify the distance between the first vehicle and the second vehicle (e.g., the compensation distance between the first vehicle and the second vehicle) to a distance of 130 meters. Then, method 900 recalculates and determines the driver demand torque (as described in one of the methods in step 906) based on the distance between the first vehicle and the second vehicle being 130 meters. The driveline torque (e.g., the torque provided by the driveline propulsion source) is then commanded to be the driver demand torque.

[0061] Similarly, if the second vehicle is within a threshold distance of a third vehicle that is directly in front of the second vehicle and in the path of the second vehicle, and if the distance between the first vehicle and the second vehicle is 150 meters, the method 900 can modify the distance between the first vehicle and the second vehicle (e.g., the offset distance between the first vehicle and the second vehicle) to a distance of 130 meters. The method 900 then recalculates and determines the driver demand torque (as described in one of the methods in step 906) based on the distance between the first vehicle and the second vehicle being 130 meters. The powertrain torque (e.g., torque provided by a powertrain propulsion source) is then commanded to be the driver demand torque.

[0062] In this way, in response to the movement of a vehicle in a convoy of vehicles ahead of the second vehicle and in the travel path of the first vehicle and the second vehicle, the driver demand torque can be further reduced for a given accelerator pedal position. This action can further reduce the likelihood of a short engine stop interval, rather than degrading the current vehicle (e.g., the first vehicle). Method 900 proceeds to exit.

[0063] therefore, Fig. 9 A method of vehicle operation is provided, comprising: receiving vehicle road position data of a first vehicle and a second vehicle to a controller; adjusting a relationship between an accelerator pedal position of the first vehicle and a powertrain torque (e.g., the accelerator pedal position is a basis for determining a driver demand torque, and the powertrain torque is commanded to be the driver demand torque) in response to a distance between the first vehicle and the second vehicle; and adjusting an output of the powertrain in response to the relationship. The method includes wherein adjusting the relationship includes adjusting a filter factor of a low pass filter for an accelerator pedal input that increases the driver demand torque, and not adjusting the filter for an accelerator pedal input that decreases the driver demand torque. The method includes wherein adjusting the relationship includes adjusting a transfer function that describes the powertrain torque as a function of accelerator pedal position. The method includes wherein adjusting the relationship includes decreasing the driver demand torque, and further includes: further adjusting the relationship in response to a distance between a second vehicle and a third vehicle. The method includes wherein the powertrain torque decreases when the distance between the first vehicle and the second vehicle decreases. The method includes wherein the powertrain torque increases when the distance between the first vehicle and the second vehicle increases. The method includes wherein adjusting the output of the powertrain includes adjusting the engine torque. The method includes where adjusting the output of the powertrain includes adjusting the motor torque.

[0064] Fig. 9The method also provides a vehicle operation method, which includes: receiving vehicle road position data of a second vehicle and a third vehicle into a controller of a first vehicle, the third vehicle being positioned in front of the second vehicle; adjusting the relationship between the accelerator pedal position and the powertrain torque of the first vehicle in response to the amount of time the nearest third vehicle is stopped and the amount of time the nearest third vehicle is moving without stopping when the second vehicle and the third vehicle are traveling in a queue of at least two vehicles; and adjusting the output of the powertrain in response to the relationship. The method also includes adjusting the relationship in response to the distance between the first vehicle and the second vehicle.

[0065] In some examples, the method includes wherein adjusting the relationship includes adjusting a filter factor of a low pass filter for an accelerator pedal input that increases a driver demand torque, and not adjusting the filter for an accelerator pedal input that decreases the driver demand torque. The method includes wherein adjusting the relationship includes adjusting a transfer function that describes the powertrain torque as a function of accelerator pedal position. The method includes wherein adjusting the output of the powertrain includes adjusting the engine torque. The method includes wherein adjusting the output of the powertrain includes adjusting the motor output. The method includes wherein the road position data of the second vehicle and the third vehicle is sent by the second vehicle and the third vehicle. The method includes wherein the road position data of the second vehicle and the third vehicle is received by a road sensor.

[0066] Note that the example control and evaluation procedures included herein can be used for different engine and / or vehicle system configurations. The control methods and procedures disclosed herein can be stored in non-transitory memory as executable instructions and can be implemented by a control system including a controller combined with different sensors, drivers and other engine hardware. The specific procedures described herein can represent one or more of any number of processing strategies (e.g., event-driven, terminal-driven, multi-tasking, multi-threading, etc.). Like this, the various actions, operations and / or functions described can be performed in the order described, in parallel or in some omitted ways. Similarly, the processing order is not necessarily required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of description and description. Depending on the specific strategy used, one or more of the actions, operations and / or functions described can be repeatedly performed. In addition, at least a portion of the described actions, operations and / or functions can be graphically represented as codes in the non-transitory memory of a computer-readable storage medium programmed in a control system. When the described actions are implemented by executing instructions in a system including various engine hardware components combined with one or more controllers, the control actions can transform the operating states of one or more sensors or drivers in the physical world.

[0067] This specification ends here. A reading of this specification by one of skill in the art will suggest many changes and modifications without departing from the spirit and scope of this specification. For example, I3, I4, I5, V6, V8, V10, and V12 engines operating in natural gas, gasoline, diesel, or alternative fuel configurations may benefit from using this specification.

Claims

1. A vehicle operating method, comprising: receiving vehicle road position data of the first vehicle and the second vehicle to the controller; adjusting a relationship between an accelerator pedal position and driveline torque of the first vehicle in response to a distance between the first vehicle and the second vehicle; wherein adjusting the relationship comprises reducing the driveline torque; adjusting the relationship further in response to a distance between the second vehicle and a third vehicle; as well as An output of the powertrain is adjusted in response to the relationship. 2 . The method of claim 1 , wherein adjusting the relationship comprises adjusting a filter factor of a low pass filter for accelerator pedal inputs that increase driver demand torque and not adjusting filtering for the accelerator pedal inputs that decrease the driver demand torque. 3 . The method of claim 1 , wherein adjusting the relationship comprises adjusting a transfer function describing powertrain torque as a function of accelerator pedal position. 4 . The method of claim 1 , wherein the driveline torque decreases as the distance between the first vehicle and the second vehicle decreases. 5 . The method of claim 1 , wherein the driveline torque increases as the distance between the first vehicle and the second vehicle increases. The method of claim 1 , wherein adjusting the output of the powertrain includes adjusting engine torque. The method of claim 1 , wherein adjusting the output of the powertrain comprises adjusting electric machine torque.

8. The method according to claim 1, further comprising: receiving vehicle road position data of the third vehicle to the controller of the first vehicle, the third vehicle being positioned ahead of the second vehicle; and The relationship between the accelerator pedal position and the driveline torque of the first vehicle is further adjusted in response to an amount of time that the most recent third vehicle was stopped and an amount of time that the most recent third vehicle was moving without stopping when the second vehicle and the third vehicle were traveling in a queue of at least two vehicles.

9. The method of claim 8, further comprising adjusting the relationship in response to the distance between the first vehicle and the second vehicle. 10 . The method of claim 8 , wherein adjusting the relationship comprises adjusting a filter factor of a low pass filter for accelerator pedal inputs that increase driver demand torque and not adjusting filtering for the accelerator pedal inputs that decrease the driver demand torque.

11. A vehicle system comprising: engine; Vehicle position sensor; accelerator pedal; and A controller including executable instructions stored in a non-transitory memory, the executable instructions being for reducing driveline torque delivered by the engine or a second propulsion source of the first vehicle in response to a constant output of the accelerator pedal and a decreasing distance between the first vehicle and the second vehicle as indicated by the vehicle position sensor, and for adjusting a relationship between a position of the accelerator pedal of the first vehicle and the driveline torque in response to an amount of time that the nearest second and third vehicles are stopped and an amount of time that the nearest second and third vehicles are moving without stopping when the second and third vehicles are traveling in a queue of at least two vehicles.

12. The vehicle system of claim 11, wherein the second propulsion source is an electric motor.

13. The vehicle system of claim 11 further comprising additional instructions for increasing driveline torque delivered by the engine or the second propulsion source of the first vehicle in response to a constant output of the accelerator pedal and an increasing distance between the first vehicle and the second vehicle as indicated by the vehicle position sensor.

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