Driveline disengagement and coasting management

A system, method, and apparatus include a controller structured to predict a change in speed of a vehicle in advance of upcoming terrain and inhibit a coasting event if the speed exceeds a limit. In one form a velocity of the vehicle is predicted using a physics based model of the vehicle within a look ahead window in front of a vehicle. Such a look ahead window can be distance or time based. In another, speed of a vehicle is monitored during a coasting event and is compared against a threshold to determine whether to remain coasting or re-engage an engine to a driveline. The threshold is a function of road grade, and permits a larger deviation from set speed at low grade than at high grade. The function can be based on road grade and vehicle weight.

TECHNICAL FIELD

The present application also relates generally to management of coasting in a vehicle for fuel economy improvement, and more particularly to idle coasting management of a vehicle with a transmission.

BACKGROUND

Improved fuel economy for vehicles can be obtained by allowing the vehicle to coast during certain operating and drive cycle conditions. However, these benefits are not heretofore realized with all vehicles, such as those with transmissions, where the operator has control over the gear selection. Therefore, there remains a significant need for the apparatuses, methods and systems disclosed herein.

SUMMARY

One example of a system, method, and apparatus includes a coasting management controller that is configured to predict whether speed will exceed a limit in a look ahead window if an engine is disengaged from a driveline. Another includes a transmission that is configured to automatically allow the vehicle to coast with the engine disengaged from the driveline at certain drive cycle conditions. Whether the engine remains disengaged from the driveline depends on monitoring speed of vehicle and comparing it against a cancellation delta that can be determined as a function of road grade.

This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

With reference toFIG. 1, there is illustrated a schematic view of an example vehicle system100including an engine102, such as an internal combustion engine, structured to generate power for the vehicle system100. The vehicle system100further includes a clutch104operably connected to the engine102and a transmission106for adapting the output torque of the engine102via the clutch104and transmitting the output torque to a drive shaft108. Vehicle system100illustrates a rear wheel drive configuration including a final drive110having a rear differential112connecting the drive shaft108to rear axles114a,114b. It is contemplated that the components of vehicle system100may be positioned in different locations throughout the vehicle system100. In one non-limiting example, in a vehicle having a front wheel drive configuration, the transmission may be a transaxle and the final drive may reside at the front of the vehicle to connect front axles to the engine via the transaxle. It is contemplated that in some embodiments the vehicle may have an all-while drive configuration, and may additionally and/or alternatively be series electric, parallel electric, and pure electric. In some forms the vehicle may be without a transmission/final drive.

In the illustrated embodiment, vehicle system100further includes two front brakes120a,120beach positioned between and operably connected to two front wheels122a,122band front axles116a,116b, respectively. Vehicle system100further includes two rear brakes124a,124beach positioned between two rear wheels126a,126band rear axles114a,114b, respectively. It is contemplated that vehicle system100may have more or fewer tires and/or brakes than illustrated inFIG. 1. In certain embodiments, vehicle system100may also include various components not shown, such as a fuel system including a fuel tank, a braking system, an engine intake system, and an engine exhaust system, which may include an exhaust aftertreatment system, to name a few examples.

Vehicle system100further includes an electronic or engine control unit (ECU)130, sometimes referred to as an electronic or engine control module (ECM), or the like, which is directed to regulating and controlling the operation of engine102. In the illustrated embodiment, the ECU130includes a transmission control unit (TCU) directed to the regulation and control of transmission106operation. A combined ECU130and TCU into a single control module may be referred to as a powertrain control module (PCM) or powertrain control unit (PCU), or the like. ECU130is in electrical communication with a plurality of vehicle sensors (not shown) in vehicle system100for receiving and transmitting conditions of vehicle system100, such as temperature and pressure conditions, for example. It is contemplated that in certain embodiments ECU130may be integrated within the engine102and/or the TCU integrated within the transmission106. Other various electronic control units for vehicle subsystems are typically present in vehicle system100, such as a braking system electronic control unit and a cruise control electronic control unit, for example, but such other various electronic control units are not show in vehicle system100to preserve clarity.

The ECU130in the illustrated embodiment is further connected to a fuel storage tank150, which is generally one component of a larger fuel delivery system. Other component typically included in a fuel system, including a fuel pump, fuel delivery conduit, and other fuel delivery components are not shown in vehicle system100to preserve clarity. ECU130is further operatively coupled with and may receive a signal from a fuel storage tank level sensor, not shown, operable to provide a signal indicating the level of fuel in the fuel storage tank150. The fuel storage tank level sensor need not be in direct communication with fuel storage tank150, and can be located at any position within vehicle system100that provides a suitable indication of applicable fuel level readings in fuel storage tank150.

In the illustrated embodiment, vehicle system100further includes a vehicle speed management (VSM) controller140operably connected to the ECU130for receiving vehicle system100sensor data and conditions. It is contemplated that in certain embodiments the VSM controller140may be integrated into the ECU130. The VSM controller140includes stored data values, constants, and functions, as well as operating instructions stored on a computer readable medium. It is further contemplated that in certain embodiments ECU130and VSM controller140may transmit data communication messages across a controller area network (CAN) bus, not shown.

The CAN bus is a vehicle bus standard message-based protocol designed to allow microcontrollers and devices to communicate with each other within the vehicle without a host computer. The CAN bus was initially designed specifically for automotive applications, though modern applications include aerospace, maritime, industrial automation, and medical equipment. It is contemplated that in certain embodiments an alternative vehicle bus protocol may be used, such as a vehicle area network (VAN) or one of the Society of Automotive Engineers (SAE) vehicle bus protocols, for example.

Any of the operations of example procedures described herein may be performed at least partially by the VSM controller140. In certain embodiments, the controller includes one or more modules structured to functionally execute the operations of the controller. The description herein including modules emphasizes the structural independence of the aspects of the VSM controller140, and illustrates one grouping of operations and responsibilities of the VSM controller140. Other groupings that execute similar overall operations are understood within the scope of the present application. Modules may be implemented in hardware and/or instructions stored on a non-transient computer readable medium, and modules may be distributed across various hardware or instructions stored on a non-transient computer readable medium. More specific descriptions of certain embodiments of controller operations are included in the section referencingFIG. 2. Operations illustrated are understood to be example only, and operations may be combined or divided, and added or removed, as well as re-ordered in whole or part, unless stated explicitly to the contrary herein.

Certain operations described herein include operations to interpret one or more parameters. Interpreting, as utilized herein, includes receiving values by any method known in the art, including at least receiving values from a datalink or network communication, receiving an electronic signal (e.g., a voltage, frequency, current, or pulse-width modulation (PWM) signal) indicative of the value, receiving a software parameter indicative of the value, reading the value from a memory location on a computer readable medium, receiving the value as a run-time parameter by any means known in the art, by receiving a value by which the interpreted parameter can be calculated, and/or by referencing a default value that is interpreted to be the parameter value. Furthermore, it is contemplated that the term sensor as used herein may include a virtual sensor, which may determine a condition directly and/or based on other data.

One example embodiment200of the VSM controller140is shown inFIG. 2. In certain embodiments, the VSM controller140includes a wheel speed input202determined from a wheel speed sensor (alternatively and/or additionally a vehicle speed sensor signal), a fuel amount input204determined from the fuel storage tank level sensor, and a brake position input206from a brake sensor operable to provide a signal indicating the brake position of any and/or all brakes120a,120b,124a, and124bin vehicle system100. VSM controller140may further include a route conditions input208, an engine conditions input210, an environmental conditions input212, and a vehicle longitudinal velocity input214which may be calculated and/or estimated using one or more vehicle sensors.

The route conditions input208may include at least one of a route grade (e.g., elevation changes of the route), an elevation, a speed limit minimum, a speed limit maximum, a route trip time, a traffic condition, a stop location and maximum and minimum acceptable speed deviations from a cruise set point. In certain embodiments, one or more of the route condition inputs208may be determined from a navigation and positioning device, such as a global position system (GPS) device, an electronic horizon device, and/or route data previously stored in memory. The engine conditions input210may include an ambient air pressure input, an ambient air temperature input, an engine throttle position input, an engine speed input, maximum and minimum available engine out torque, a vehicle mass, and in some forms an engine torque input determined from one or more engine102and/or engine intake system sensors. The environmental conditions input may include a wind input, a precipitation condition, an altitude input, and/or a relative humidity input, an indication of current traffic conditions or proximity to adjacent vehicles each of which may be determined using the one or more vehicle sensors in vehicle system100or communicated to the vehicle through vehicle to vehicle or vehicle to server techniques.

The VSM controller140illustrated inFIG. 2includes a section grade and surface classification module230, a speed mode determination module240, and a speed reference determination module250. Other VSM controller140arrangements that functionally execute the operations of the VSM controller140are contemplated in the present application.

The section grade and surface classification module230receives and interprets the route grade and divides the route grade into one or more sections based on a predetermined section length. The section grade and surface classification module230further determines an average grade234over at least a portion of the one or more sections and a surface classification232for each of the one or more sections. An example section grade and surface classification module230determines the surface classification232for each section based on each section's grade over the predetermined section length and a grade percentage threshold for each classification. Each section may be classified as one of an uphill surface when the section grade has a positive grade greater than or equal to an uphill surface percentage threshold, a downhill surface when the section grade has a negative grade less than or equal to a downhill surface percentage threshold, or a flat surface when the section grade has a positive grade less than uphill surface percentage threshold or a negative grade greater than the downhill surface percentage threshold.

The speed mode determination module240receives and interprets the surface classification232for each section and the average grade234to determine a vehicle speed mode242(e.g., a speed mode of a vehicle operating with an active cruise control set point). An example speed mode determination module240may determine each section as being one of a cruise speed mode (i.e., return to or maintain a cruise speed that may be defined by the operator of the vehicle), a pre-uphill speedup speed mode (i.e., speed up before entering an upcoming uphill surface), an uphill slowdown speed mode (i.e., slow down during a hill surface), a pre-downhill slowdown speed mode (i.e., slow down before entering an upcoming downhill surface), and a downhill speedup speed mode (i.e., speed up during a downhill surface).

The speed reference determination module250receives and interprets the surface classification232and the average grade234to determine a vehicle speed reference command252. In certain embodiments, the speed reference determination module250further determines the vehicle speed reference based on at least one of the wheel speed input202, the fuel amount input204, the brake position input206, the route conditions input208, the engine conditions input210, the environment conditions input212, and the vehicle longitudinal velocity214. In certain embodiments, the speed reference determination module250is configured to provide the vehicle speed reference command252to one or more vehicle speed regulators and/or one or more output devices. In certain embodiments, the vehicle speed reference command252provided to the one or more vehicle speed regulators may include one or more of a brake actuator position command, a throttle actuator position command, a torque command, a transmission gear ratio command, a fuel injection command, a final drive selection command, a cruise control speed setting command, and/or a requested speed command. In certain embodiments, the one or more output devices configured to receive the vehicle speed reference command252may include a dashboard device, a printer, a handheld or mobile device, a public datalink, a device in operative communication with a public datalink, a private datalink, a device in operative communication with a private datalink, a non-transient memory storage location, a non-transient memory buffer accessible to a datalink, a remote network, a device in operative communication with a remote network, and/or a like device capable of displaying an indication of the vehicle speed reference command252.

A non-limiting example includes the speed reference determination module250configured to provide the vehicle speed reference command252to an output device which is a non-transient memory storage location. The vehicle speed reference command252is read from the non-transient memory storage location and utilized to adjust a speed reference for a vehicle, for example as a cruise control set speed adjustment.

Another non-limiting example includes the speed reference determination module250configured to provide the vehicle speed reference command252to an output device which is a public datalink, a device in operative communication with a public datalink, a private datalink, a device in operative communication with a private datalink, and/or a non-transient memory buffer accessible to a datalink. The vehicle speed reference command252is read from the datalink and/or the datalink buffer and provided to a location visible to a vehicle operator, such as a dashboard display or other visible location.

Yet another non-limiting example includes the speed reference determination module250configured to provide the vehicle speed reference command252to an output device which is a remote network and/or a device in operative communication with a remote network. The communication to the remote network may pass through intermediate communications, such as through a public or private datalink. The vehicle speed reference command252in the example is read from the remote network, and provided to a location visible to one of a vehicle operator and/or a fleet operator. An example includes a smart phone or mobile device providing the vehicle speed reference command252to the vehicle operator. Another example includes a remote device, such as a smart phone, laptop, desktop, or mobile device, providing the vehicle speed reference command252to the fleet operator. The fleet operator may adjust a vehicle speed reference, either remotely or in a calibration event at a later time—for example for vehicles that will be traveling on the route the current vehicle is traveling on, and/or the fleet operator may utilize the vehicle speed reference command252in future fleet planning operations. The described examples are non-limiting, and the inclusion of an example should not be considered to limit potential operations of devices or parameters that are either utilized in the examples or omitted from the examples.

FIG. 3illustrates another example embodiment300of the VSM controller140.FIGS. 4-7illustrate example embodiments of the input and output signals of the embodiment300to and from the VSM controller140, respectively. With reference toFIG. 3, the VSM controller140receives a route grade signal302and a current velocity input304.

The route grade signal302is provided to the section grade and surface classification module230. A non-limiting example of the route grade signal302is illustrated inFIG. 4. The route grade signal302may contain data for an entire route the vehicle will be travelling during a route trip. It is contemplated that in certain embodiments only a portion of the entire route may be provided to the section grade and surface classification module230, with a different portion of the entire route being provided at different intervals throughout the route trip. In one non-limiting example, the route grade may be provided in two mile length increments. It is further contemplated that additional inputs may be received and interpreted by the section grade and surface classification module230in addition to or as an alternative to the route grade signal302. Such signals may include an elevation signal, a route position signal, a speed limit signal, a traffic signal, signal indicating the proximity of adjacent vehicles, a wind signal, a road condition signal, a precipitation signal, an ambient pressure and/or temperature signal, a throttle position signal, a brake position signal, a fuel amount signal, an air/fuel ratio signal, an engine torque signal, and/or any derivative or second derivative of one of the signals which may be detected or calculated based on one or more sensors positioned throughout vehicle system100.

In certain embodiments, the section grade and surface classification module230includes an elevation filtering module312, a route grade sectioning module316, a section grade averaging module320, and a surface classification module324. The elevation filtering module312outputs a filtered route grade314in response to the route grade signal302and a route grade filter. The filtered route grade314may be filtered by a zero phase shift low pass filter structured to reduce signal noise in the route grade. Different types of filters are contemplated, such as a high pass filter, a band pass filter, and a moving average filter, for example. It is further contemplated that other signals where noise is present in the signal may be filtered.

The route grade sectioning module316receives the filtered route grade314and sections of the filtered route grade314into a route sections output318based on the filtered route grade314and a section length, or resolution. In one non-limiting example, where the route grade provided is two miles in length and the section length is one-tenth of a mile, the route sections output318would be comprised of twenty route sections, each having a section grade and a length of one-tenth of a mile.

The section grade averaging module320receives the route sections output318and determines the average grade234based on each section grade of the route sections output318and the total number of route sections included in route sections output318.

The surface classification module324receives the average grade234and determines a surface classification232for each route section. One non-limiting example of the surface classification232is illustrated inFIG. 5. An example surface classification module324determines the surface classification232for each route section based on each section grade and a classification threshold for each classification. In certain embodiments, each route section may be classified as one of the following surface classifications: an uphill surface, a downhill surface, and a flat surface. In one example non-limiting embodiment, the classification threshold may be a grade percentage. For example, when the section grade has a positive grade greater than an uphill surface percentage threshold, the route section may be classified as the uphill surface, when the section grade has a negative grade less than a downhill surface percentage threshold, the route section may be classified as the downhill surface, and when the section grade has a positive grade less than or equal to uphill surface percentage threshold or a negative grade greater than or equal to the downhill surface percentage threshold, the route section may be classified as the flat surface. In certain embodiments, it is contemplated that other thresholds may be used in addition to and/or alternatively to the grade percentage classification threshold, such as a hysteresis based threshold defined as a function of the current state, and/or determining a threshold using a search heuristic, such as a genetic algorithm, and/or adaptive control logic.

In certain embodiments, the speed mode determination module240includes a mode identification module332and a mode identification adjustment module336. The mode selection system is provided the average grade234and the surface classification232. The mode identification module332receives the surface classification232and determines a speed mode output334for each route section based on the surface classification232. In certain embodiments, the speed mode output334may be based on a lookup table as a function of a current route section and a next route section. In certain embodiments, the current route section may be the route section from the route sections in which the vehicle is currently travelling in and the next route section may be the route section from the route sections in which the vehicle will be travelling in immediately following the current route section. An example mode identification module332may identify each route section as being one of a cruise mode (i.e., return to or maintain cruise speed set point), a pre-uphill speedup mode (i.e., speed up before entering the upcoming hill), an uphill slowdown mode (i.e., slow down during the hill), a pre-downhill slowdown mode (i.e., slow down before entering the upcoming downhill), and a downhill speedup mode (i.e., speed up during the downhill). In certain embodiments, it is contemplated that one or more additional modes may be used by the example mode identification module332to identify each route section, such as a no speed change mode and/or a coast mode, for example.

The mode identification adjustment module336receives the average grade234and the speed mode output334as inputs to determine and output the vehicle speed mode242to allow for a pre-hill adjustment length, which may be applied to each route section. In certain embodiments, the vehicle speed mode242may be based on a lookup table as a function of the current route section and the next route section, an example of which is further detailed inFIG. 8.

The current velocity input304is provided to the speed reference determination module250. In the illustrated embodiment, the speed reference determination module250includes a speed mode selector module346, a speed reference determination module350, and a speed reference determination module354. The speed reference determination module250further includes a piecewise linear parameter module342that receives the surface classification232for each route section and determines a speed modes output344for each route section based on the surface classification232for each route section. In certain embodiments, a piecewise linear function of route section distance and route section amplitude may be used to determine the speed mode for each route section. It is contemplated that in certain embodiments a nonlinear function, a polynomial function, an exponential function, a logarithmic function, a trigonometric function, a spline function, a constant function, and/or the like may be used in addition to and/or as an alternative to the piecewise linear function.

The speed mode selector module346receives the vehicle speed mode242and the speed modes output344to determine a current speed mode output348for the current route section. The current velocity input304and current speed mode output348are received by the speed reference determination module350, which determines a speed reference output352. In certain embodiments, speed reference output352may be determined utilizing the following equation:
V(i+1)=V(i)+a*dxEquation 1
wherein V is the velocity and a is the rate of change velocity with respect to distance. It is contemplated that the velocity values used in Equation 1 may be measured, calculated, and/or modeled. In certain embodiments, the average grade234may be used to further determine speed reference output352.

The speed reference adjustment module354receives the speed reference output352and determines the vehicle speed reference command252. The vehicle speed reference command252may include one or more vehicle speed references sent to one or more components of vehicle system100. In one example, the vehicle speed reference command252may be a brake actuator position for a brake actuator in a braking system. Other non-limiting examples include a throttle actuator position, a transmission gear ratio, a final drive selection, a cruise control set point, a fueling command, a torque request, and/or a requested speed. The vehicle speed reference command252may be determined using an output limiting threshold, such as a rate limiting threshold and/or saturation threshold, for example.

As noted previous,FIGS. 4-7illustrate example embodiments of the input and output signals of the embodiment300of the VSM controller140.FIG. 4illustrates a route grade line chart400having a grade variable Y-axis402, a position variable X-axis404, and a route grade signal406.FIG. 5illustrates a surface classification line chart500having a surface classification variable Y-axis502, a position variable X-axis504, and a surface classification signal506.FIG. 6illustrates a speed mode line chart600having a speed mode variable Y-axis602, a position variable X-axis604, and a speed mode signal606.FIG. 7illustrates a reference velocity line chart700having a velocity variable Y-axis702, a position variable X-axis704, and a reference velocity signal706.

FIG. 8illustrates an example speed mode lookup table800as a function of a current route section axis802and a next route section axis804. Each route section axis802,804includes each surface classification for mapping a current speed mode based on the current route section and the next route section. For example, when the current route section is classified as an uphill surface and the next route section is classified as a downhill surface, the current speed mode would be set to the pre-downhill slowdown mode. It is contemplated that different surface classifications and/or speed modes may be used in addition to or as an alternative to the surface classifications and speed modes illustrated inFIG. 8, in which case the speed mode lookup table axes802,804may be modified to reflect the different surface classifications and/or speed modes.

With reference toFIG. 9, there is illustrated a flow diagram of an example procedure900for determining a vehicle speed reference. In certain embodiments the vehicle speed reference may be provided to a vehicle system, such as vehicle system100, to control a vehicle speed for a vehicle in that is put into operation by programming the VSM controller140for use in, for example, vehicle system100. In certain embodiments, the example procedure900may be used to control the vehicle speed of a vehicle operating in an active cruise control mode. In addition to or as an alternative to providing the vehicle speed reference to the vehicle system to control the vehicle speed, it is contemplated that in certain embodiments the vehicle speed reference may be provided to an output device for displaying an indication of the vehicle speed reference. Such output devices may include a dashboard device, a printer, a handheld or mobile device, a public datalink, a device in operative communication with a public datalink, a private datalink, a device in operative communication with a private datalink, a non-transient memory storage location, a non-transient memory buffer accessible to a datalink, a remote network, a device in operative communication with a remote network, and/or a like device capable of displaying an indication of the vehicle speed reference. Procedure900begins at operation902, in which a control routine is started for providing a route grade signal to VSM controller140to determine the vehicle speed reference. Operation902may begin by interpreting a key-on event, completion of a cycle, restarting procedure900, or by initiation by the vehicle operator or a technician.

Procedure900continues to operation904, where a route grade is determined based on the route grade signal. It is contemplated that in certain embodiments, the route grade may be for the entire route or a portion of the route. It is further contemplated that the route grade signal may be filtered, such as by a low pass filter, for example. Procedure900continues from operation904to operation906, where route sections are determined based on the route grade signal and a route section length. It is contemplated that in certain embodiments the route section length may be a static length defined at the beginning of the route and/or a dynamic length that may be redefined throughout the route. Procedure900continues to operation908, where an average grade is determined based on the route grade and the route section length. In certain embodiments a simple averaging function may be used. It is contemplated that in certain embodiments the average grade function may only use a portion of the route grade.

From operation908, procedure900continues to procedure910, where a current section and a next section are determined from the route sections determined at operation906. Procedure900continues to operation912, where each of the current and next sections are classified with a surface classification. It is contemplated that in certain embodiments a threshold may be used to reduce/remove signal chattering, or signal deviations, to determine the surface classification. In certain embodiments, the surface classification may include one of an uphill surface, a downhill surface, and/or a flat surface. Procedure900continues from operation912to operation914, where a speed mode is determined for each of the current and next sections based on the surface classification for each section determined in operation912. The speed mode for each section may be determined using a lookup table as a function of the current section surface classification and the next section surface classification. In certain embodiments the speed mode may include a cruise mode, a pre-uphill speedup mode, an uphill slowdown mode, a pre-downhill slowdown mode, and/or a downhill speedup mode.

From operation914, procedure900continues to operation916, where an adjusted speed mode for the current section is determined based on the current and next section speed modes determined in operation914. Procedure900then continues to operation918, where a vehicle speed reference command is determined. In certain embodiment, the vehicle speed reference command may be determined as a function of the current velocity, the average grade, and the current speed mode. Procedure900continues from operation918to operation920, where a vehicle speed is controlled based on the vehicle speed reference command determined at operation918. In certain embodiments, the vehicle speed reference command may include one or more vehicle speed reference commands sent to the ECU130, another controller, and/or directly to one or more speed control components of vehicle system100. The speed control components may include a brake actuator, a throttle actuator, a fuel injector, a transmission gear, a final drive, a cruise control system, and/or an engine request directed toward engine torque, for example. Procedure900is complete and ends at operation922, where procedure900may be restarted such that the section after the next route section becomes the next route section and the previous next route section becomes the current route section. Procedure900may be repeated for the entire route grade signal.

Additionally and/or alternatively to the embodiments above, a coasting management controller can be provided that in some forms is incorporated into the VSM controller140and/or is a supplemental controller to any other controller used in the vehicle such as a conventional cruise controller (or can be a completely self-contained standalone controller). For that matter, the coasting management controller can include any necessary control modules described herein, such as but not limited to modules needed for hill classification, route/environment parameter processing, and a hook for communication with the TCU, as will be appreciated by those of skill in the art.

The coasting management controller1000can be structured to receive inputs such as the embodiment200depicted above inFIG. 2, as well as any number of other inputs, and output a control signal useful in the regulation of vehicle speed. In one form the coasting management controller can be used to manage disengagement of the engine104to the driveline107to provide for a controlled coasting event in light of upcoming road conditions, such as grade, speed limits, etc that are mentioned above and below, for example with respect to the section related modules and route related modules. The coasting management controller can be used to maintain disengagement of the engine104to driveline107so long as certain conditions are being met. The instant application describes techniques to inhibit the activation of a coasting event (and thus maintain engagement of the engine104to driveline107) if certain conditions are not met.

Turning now toFIG. 10, one embodiment of the coasting management controller can be seen pictorially regulating the speed of a vehicle100as it approaches a descent via grade1010in a road, and determining whether to inhibit activation of a coasting event. It will be appreciated that the term “road” as used herein is intended to encompass improved and nonimproved throughways upon which a vehicle can be travelling. Thus, a gravel road or a dirt road can also be included, whether or not the road is specifically demarcated by a recognized edge such as a cleanly laid edge or marker. For example, a ‘road’ across a dry lake bed may very well be a path which may or may not have been previously travelled upon. Thus, the term ‘road’ and any other term that connotes a path upon which the vehicle is travelling is intended to reasonably encompass the above interpretation.

FIG. 10depicts at the top the grade prior to heading downhill and various velocity related details of the vehicle movement plotted as a function of distance. The velocity related details include items such as: engine brake activation speed1020, a “cancel delta”1030which relates to lower speed at which in one embodiment the coasting management controller will disengage if exceeded, a cruise set speed1040which relates to a speed at which the vehicle will be regulated during engagement of the coasting management controller.

As suggested in the figure, a look ahead-window1050is used in advance of the grade1010to predict vehicle speed if the engine104is disengaged from the driveline107during a coasting event. Speed is predicted at individual points1060in the look-ahead window1050using any variety of techniques. In one form speed at the individual points is predicted using a physics based model of the vehicle100. In one such form, the physics based model takes into consideration the grade of the upcoming terrain (e.g. grade1010). The grade is provided to a speed change procedure that is used to compute a change in speed of the vehicle as a result of a grade in the terrain upon which the vehicle is travelling. The grade of the upcoming terrain can in some forms be continuously updated in the controller as the vehicle travels upon the terrain. Such data can be provided via on-board memory calls, RF reception, electronic bus communications, inter-vehicle network communication, etc. The grade data can take any variety of forms.

For example, the grade data can be a look ahead vector in which each data point in the vector corresponds to a data point in a position vector (e.g. the position vector can represent evenly spaced data points at distance intervals in advance of the vehicle). Such a pairing of grade and position vectors could represent a constantly updated data set as the vehicle travels along a road with both vectors representing look-ahead information. Not all datasets need include evenly spaced position data points.

Alternatively, the grade data can be a look ahead vector in which each data point in the vector corresponds to a data point in a time vector (e.g. the time vector can represent evenly spaced data points at future time intervals in advance of the vehicle). Such a pairing of grade and time vectors could represent a constantly updated data set as the vehicle travels along a road with both vectors representing look-ahead information. Not all datasets need include evenly spaced position data points.

The physics based model can be structured to produce a speed change of the vehicle denoted as dV. In one form a speed change module uses information such as power available from the engine, vehicle speed, vehicle mass, etc to predict a change in vehicle speed as a result of the grade. In one nonlimiting embodiment the change in speed can be represented as:

dV=(Peng-Pss,cruise-Pgrade)⁢Lm·v2
Where dV represents the change in speed; Pengrepresents either the motoring power or the max power of the engine depending upon whether the grade is positive or negative; Pss,cruiserepresents the power required for the vehicle to maintain steady cruise set speed; L is the length of the grade segment, m is the mass of the vehicle, and v is vehicle speed; and Pgradeis the grade power (e.g. m*g*sin(grade angle)*v where the symbols are the same as elsewhere in the equation and g is gravity). Since a change in velocity is calculated when the driveline is disengaged, Pss,cruisecan be set to 0 in the equation above.

In the illustrated embodiment inFIG. 10, the coasting management controller calculates speed at the individual points1060in the look ahead window1050. The look ahead window1050is set at 2 km in the illustrated embodiment, but can be longer or shorter in other embodiments. The individual points1060are set at 200 m increments in the illustrated embodiments, but the increments can also take on other sizes (larger or smaller), and in some forms may not be evenly spaced throughout the look ahead window. In some forms the increments can be as low as 0.5 meters. In still other forms the increments can be between 0.5 meters and 200 m, such as 100 m to set forth just one non-limiting embodiment in this range.

In other embodiments in which the look ahead information is expressed in the time domain as suggested above, the spacing can be anywhere from 200 ms to 5 seconds, but the increments can also take on other sizes, and in some forms may not be evenly spaced throughout the look ahead window.

As suggested above, the increments and/or range used when expressing the look ahead window as a distance or as a time can be evenly spaced, but can also be unevenly spaced. Such an altered point resolution (e.g. longer or shorter distance or time steps in the window) can be based upon any number of conditions. For example, conditions such as grade (e.g. steeper grades could use smaller steps) or vehicle speed (higher speeds could use smaller steps) could influence the nature of the spacing between points across the look ahead. The altered point resolutions could be applied to all calculations (e.g. if the predicted route includes a steep grade, then change the size down) or change along a predicted route (e.g. shorter windows could be used where more rapid speed changes are expected). Determinations of the size of window and increment sizes within the window (whether time or distance based) can be made by considerations of contemplated grades, acceptable speed change amounts, processor throughput limitations, and available route prediction resolution values.

As mentioned above, the instant application includes techniques to inhibit the activation of a coasting event (and thus maintain engagement of the engine104to driveline107) if certain conditions are not met; the corollary of which is that when those conditions are met the techniques described herein permit activation/request a coasting event. Such an ability to inhibit on the one hand or permit activation/request a coasting event on the other can be based upon a time or distance based look ahead window as discussed in the alternatives above, and in some forms can include a persistence counter of any size before inhibition and/or activation/request can be initiated. The coasting management controller uses the look ahead window1050, and in particular the predicted speed at the points1060in the look ahead window, to determine whether predicted speed given the grade1010will remain within vehicle speed limits1020and1030. As shown inFIG. 10, the predicted velocity at each of the points1060remains within the upper limit1020and the lower limit1030. Thus, the coasting management controller will not inhibit the disengagement of the engine104to the driveline107(e.g. in some forms it can request the initiation of a coasting event) in the embodiment shown inFIG. 10.

The upper limit1020and/or the lower limit1030can be preset limit fixed for the duration of operation of the coasting management controller, but in some forms the limits can vary depending on any number of factors, whether based on real-time feedback of road conditions, and/or taken from a calibration table. In one form the speed limits1020and/or1030are calibratable thresholds over a calibratable distance.

FIG. 11depicts one example of a grade1010that produces a predicted speed in excess of the limit1020. In the illustration ofFIG. 11, predicted speed exceeds the limit1020at the last point1060in the look ahead window1050. In this example, the coasting management controller will inhibit disengagement of the engine104from the driveline107(it will not request a coasting event) since predicted speed will exceed a limit at some point in the look ahead window1050.

With reference toFIG. 12, there is illustrated a schematic view of an exemplary vehicle2002including a powertrain2004incorporated within vehicle2002. In the illustrated embodiment, the powertrain2004includes an engine2006, such as an internal combustion engine, structured to generate power for the vehicle2002. The powertrain2004further includes a transmission2010connected to the engine2006for adapting the output torque of the engine2006and transmitting the output torque to a driveline2012including drive shaft2014. In certain embodiments, the transmission2010is a transmission that may be disengageably connected to an engine crankshaft2008via a clutch2016. The transmission can be any one of different transmission types. To set forth just a few non-limiting embodiments, the transmission can be an AMT (automated manual transmission), CVT (continuously variable transmission), manual transmission, etc.

In the rear wheel drive configuration illustrated for vehicle2002, the driveline2012of powertrain2004includes a final drive2018having a rear differential2022connecting the drive shaft2014to rear axles2024,2026. It is contemplated that the components of powertrain2004may be positioned in different locations throughout the vehicle2002. In one non-limiting example of a vehicle2002having a front wheel drive configuration, transmission2010may be a transaxle and final drive2018may reside at the front of the vehicle2002, connecting front axles2028and2030to the engine2006via the transaxle. It is also contemplated that in some embodiments the vehicle2002is in an all-wheel drive configuration.

In the illustrated embodiment, vehicle2002includes two front wheels2034,2036mounted to front axles2028,2030, respectively. Vehicle system2002further includes two rear wheels2038,2040mounted to rear axles2024,2026, respectively. It is contemplated that vehicle2002may have more or fewer wheels than illustrated inFIG. 12. Vehicle2002may also include various components not shown, such as a fuel system including a fuel tank, a front differential, a braking system, a suspension, an engine intake system and an exhaust system, which may include an exhaust aftertreatment system, to name a few examples.

Vehicle2002includes an electronic or engine control unit (ECU)2042, sometimes referred to as an electronic or engine control module (ECM), or the like, which is directed to regulating and controlling the operation of engine2006. A transmission control unit (TCU)2044is illustrated in vehicle2002, which is directed to the regulation and control of transmission2010operation. ECU2042and TCU2044are each in electrical communication with a plurality of vehicle sensors (not shown) in vehicle2002for receiving and transmitting conditions of vehicle2002, such as temperature and pressure conditions, for example. In certain embodiments, the ECU2042and the TCU2044may be combined into a single control module, commonly referred to as a powertrain control module (PCM) or powertrain control unit (PCU), or the like. It is contemplated that ECU2042and/or TCU2044may be integrated within the engine2006or transmission2010, respectively. Other various electronic control units for vehicle subsystems are typically present in vehicle system2002, such as a braking system electronic control unit and a cruise control electronic control unit, for example, but such other various electronic control units are not show in vehicle2002to preserve clarity.

Vehicle system2002further includes a cycle efficiency management (CEM) module2046, which may be directed to the control of the operations described herein and/or directed toward an intermediary control for the regulation and control of the powertrain2004in vehicle system2002. In the illustrated embodiment, CEM module2046is in electrical communication with each of the ECU2042and TCU2044. In certain embodiments, at least a portion of the CEM module2046may be integrated within the ECU2042and/or TCU2044. CEM module2046may further be in electrical communication with one or more of the plurality of vehicle sensors in vehicle2002for receiving and transmitting conditions of vehicle2002, such as temperature and pressure conditions, route conditions, terrain conditions, speed conditions, and weather conditions, for example. It is contemplated that at least a portion of the conditions and/or measured inputs used for interpreting signals by the CEM module2046may be received from ECU2042and/or TCU2044, in addition to or alternatively to the plurality of vehicle sensors. Furthermore, the CEM module2046may include a processor or controller and be a control unit.

The CEM module2046includes stored data values, constants, and functions, as well as operating instructions stored on, for example, a computer readable medium. Any of the operations of exemplary procedures described herein may be performed at least partially by the CEM module2046. In certain embodiments, the controller includes one or more modules structured to functionally execute the operations of the controller. The description herein including modules emphasizes the structural independence of the aspects of the CEM module2046, and illustrates one grouping of operations and responsibilities of the CEM module2046. Other groupings that execute similar overall operations are understood within the scope of the present application. Modules may be implemented in hardware and/or instructions on computer readable medium, and modules may be distributed across various hardware or computer readable medium components. More specific descriptions of certain embodiments of controller operations are included in the section referencingFIG. 13. Operations illustrated are understood to be exemplary only, and operations may be combined or divided, and added or removed, as well as re-ordered in whole or part, unless stated explicitly to the contrary herein.

Certain operations described herein include operations to interpret one or more parameters. Interpreting, as utilized herein, includes receiving values by any method known in the art, including at least receiving values from a datalink or network communication, receiving an electronic signal (e.g., a voltage, frequency, current, or pulse-width modulation (PWM) signal) indicative of the value, receiving a software parameter indicative of the value, reading the value from a memory location on a computer readable medium, receiving the value as a run-time parameter by any means known in the art, and/or by receiving a value by which the interpreted parameter can be calculated, and/or by referencing a default value that is interpreted to be the parameter value.

One exemplary embodiment of CEM module2046is shown inFIG. 13. The CEM module2046may include an engine fueling map2050, an engine braking/friction map2052, and a coasting management module2054, among other modules. Example other modules include an operations cost module, a vehicle speed management module, a fuel quantity management module, a transient torque management module, a transmission arbiter module, a cruise control arbiter module, a throttle arbiter module, and an operator override module. Other arrangements that functionally execute the operations of the CEM module2046are contemplated in the present application. For example, additional CEM module and cruise control operation aspects with which the present invention may have application may be found with reference to U.S. Provisional Application Ser. No. 61/941,850 filed on Feb. 19, 2014 which is a priority document to U.S. Patent Application Publication No. 2015-0239454 A1, as well as U.S. patent application Ser. No. 14/261,010 filed on Apr. 24, 2014 and published as U.S. Patent Application Publication No. 2015-0306957 A1, each of which is incorporated herein by reference for all purposes.

In certain embodiments, the CEM module2046receives operating inputs2048, such as a fuel amount input, a weather conditions input from one or more sensors and/or one or more external devices for detecting weather conditions, and a route conditions input from one or more sensors and/or one or more external devices for detecting route conditions. The fuel amount may include the amount of fuel remaining in the fuel tank. The weather conditions may include a humidity level, a wind condition, and a precipitation condition. The route conditions may include a trip distance, an elevation profile, a route grade profile, a grade length, a maximum speed limit, a minimum speed limit, a traffic condition, and a road condition.

The CEM module2046illustrated inFIG. 13includes engine conditions2064input from the ECU2042and transmission conditions2066input from the TCU2044. In certain embodiments, the engine conditions2064and transmission conditions2066may be determined from a plurality of sensors positioned throughout vehicle2002. Engine conditions2064may include a brake actuation parameter, a throttle position parameter, a torque request parameter, an ambient air pressure, an ambient air temperature, an engine temperature, an engine torque, an engine speed, an engine speed rate of change, an engine degrade state, and a brake position. Transmission conditions2066may include a transmission gear ratio, a current transmission gear, a final drive ratio, a clutch actuator position, and a neutral gear state.

In operation, CEM module2046is a tool based on a series of operation control modules that provide both anticipated and currently desired vehicle2002operation behavior to optimize fuel economy. The series of operation control modules are focused on the components of vehicle2002, and more specifically the components of powertrain2004. For a given travel route and one or more route constraints, the recommendations or outputs made by the CEM module2046is dependent on the operating inputs2048, engine conditions2064, transmission conditions2066, the engine fueling map2050and the engine braking/friction map2052. Maps2050,2052may be in the form of multidimensional performance maps, or lookup tables, calibrated offline and provided by the engine manufacturer. It is contemplated that in certain embodiments the engine braking/friction map2052may be obtained from the engine fueling map2050, while in others the engine fueling map2050may be obtained from the engine braking/friction map2052.

CEM module2046is operable to assume active control of the vehicle2002, regulating a vehicle speed, the engine torque curve, and/or other powertrain2004operating conditions to ensure optimal vehicle2002operation, or passive control which allows the operator to take recommended actions. In the present application, CEM module2046includes coasting management module2054operable to interpret operating inputs2048, engine conditions2064, and transmission conditions2066to determine a coasting opportunity2056is available, and to automatically (without operator input) disconnect the engine2006from the driveline2012in a vehicle with a transmission2010to enable coasting of vehicle2002to obtain, for example, fuel economy benefits.

In response to coasting management module2054interpreting or receiving an input that a coasting opportunity is available for vehicle2002or desired, CEM module2046outputs, in a first embodiment, a transmission gear command or request2058to TCU2044or, in a second embodiment, a clutch actuator command or request2060to TCU2044. It will be appreciated herein that use of the term “command” can also include “or request”, and vice versa, unless indicated to the contrary. In some embodiments a gear or clutch “command” may more properly be referred to as a “request”. For example, a request may be sent to the transmission control unit and the TCU makes a decision as whether to honor the request or not based upon a number of conditions. Transmission gear command or request2058and clutch actuator command or request2060each disengage engine2006from driveline2012in response to coasting opportunity2056to provide coasting operation of vehicle2002.

In one embodiment, transmission gear command or request2058controls an actuator2032(shown inFIG. 12as located within the contours of the transmission2010, but it will be appreciated that the actuator2032can be located elsewhere) that actuates transmission2010to achieve a neutral gear position to disconnect engine2006from driveline2012. In another embodiment, clutch actuator command or request2060actuates a clutch actuator2020associated with clutch2016to disengage clutch2016and disconnect engine2006from driveline2012. Transmission1gear command or request2058or clutch actuator command or request2060can be activated by CEM module2046during cruise control operation of vehicle2002, or anytime when CEM module2046is active for controlling operations of vehicle2002in response to certain conditions. Transmission gear command or request2058or clutch actuator command or request2060can be overridden by operator input2062, such as when the operator increases the throttle position, pushes a brake pedal, or moves a gear level, to re-engage engine2006to driveline2012and terminate coasting operation of vehicle2002.

In one embodiment, the transmission gear command or request2058is an actuator that achieves a neutral position of the transmission2010by using a range shift or split shift cylinder to obtain the neutral position. Although not explicitly shown in the figures, it will be appreciated by those in the technical field that either the range shift or split shift cylinder can be located within the contours of the transmission2010or elsewhere. To set forth one non-limiting example, one or more components of either the range or split shift can be located in an auxiliary housing, such as but not limiting to an auxiliary housing located between the transmission2010and the drive shaft2014. A splitter that is typically used for a transmission is actuated by actuator2032to move between high and low split positions so that a neutral position is obtained. In another embodiment, the actuator2032arranges the splitter so that when fully engaged to the high or low position, a neutral position is obtained since no gear meshes are connected to an output shaft of transmission2010, such as drive shaft2014. In yet another embodiment, a range shift is configured to select neutral in response to the transmission gear command or request2058. Transmission2010can be configured so that actuation to the neutral position is obtained without clutch actuation, such as currently performed in shifting between top gears of some currently available transmissions.

Although as discussed above the CEM module2046can be structured to output a command or request to disengage the engine2006from the driveline2012in response to a coasting opportunity, the CEM module2046can also be structured to monitor performance of the vehicle2002and re-engage the engine2006to the driveline2012when conditions warrant. Such re-engagement can occur when vehicle speed exceeds a threshold, the condition of which can be monitored by the CEM2046or other suitable module during the coasting event.

FIG. 14depicts an illustration of velocity2068as it naturally diverges from the isochronous speed2070as a result of disturbances such as road conditions, wind, vehicle drafting, etc. In this non-limiting embodiment the CEM module2046is in active control of the vehicle2002and the isochronous speed2070represents a cruise control set speed of the controller that is set by a driver. The embodiments disclosed and discussed inFIGS. 15-17as included in the CEM2046can alternatively be incorporated into any form which embodies and/or includes the coasting management controller disclosed and described inFIGS. 10-11, and vice versa.

A cancel delta threshold2072is shown below the isochronous speed2070and it represents a delta speed divergence from the isochronous speed2070at which point the CEM2046re-engages the engine2006to the driveline2012. Such a situation might occur when a coasting vehicle encounters a road grade that is level, that is rising, or that is insufficiently steep. These situations may occur at the end of a long grade, but may also occur mid grade in which a local rise in terrain results in a reduction in vehicle speed. Although the cancel delta threshold2072is shown as a constant in the illustration inFIG. 14, the cancel delta threshold2072can be implemented in a number of different manners as described further below.

Turning now toFIG. 15, one embodiment of the cancel delta threshold2072is shown which has been implemented as a function of grade of terrain (which can be measured or can be from the route grade profile). At low grades the cancel delta2072has a maximum value2074, while at higher grades the cancel delta2072has a minimum value2076. The cancel delta2072transitions from the maximum value2074to the minimum value2076at a first grade2078, and completes the transition from maximum value2074to minimum value2076at a second grade2080. The transition from maximum value2074to minimum value2076can be implemented as a straight-line in which intermediate values can be determined through linear interpolation. Other implementations are also contemplated.

The selection of maximum and minimum values of the cancel delta, as well as the particular grades at which the transitions occur, can be found through a number of techniques. For example, a given route having known terrain features can be studied to determine appropriate values for each. In other settings a Design of Experiments can be run using a number of separate simulations to determine (e.g. through the use of regression analysis) which values of the maximum, minimum, and transition points are appropriate to achieve adequate performance. In one non-limiting form the max cancel delta can be 3 mph, with the minimum cancel delta at 1.24 mph.

The maximum cancel delta2074implemented inFIG. 15permits a relatively wider variation in vehicle speed in situations in which the vehicle encounters an intermediate rise in terrain on an otherwise longer downhill stretch. The relatively wider variation will assist in keeping the engine2006disengaged from the driveline2012for a coasting event when these intermediate rises in terrain are followed by a continued downhill coasting event.

On the other side of the cancel delta profile shown inFIG. 15, the minimum cancel delta2076seeks to re-engage the engine2006to the driveline2012in the presence of smaller variations from isochronous speed2070. For example, a steep rise in terrain will result in rapid reduction in speed and thus quicker re-engagement of the engine2006to the driveline2012may be desired to avoid excessively low speeds at the re-engagement.

The cancel delta2072profile shown as a function of grade inFIG. 15can be implemented in a variety of manners. In one non-limiting embodiment, the cancel delta2072profile can be implemented in a look-up table (LUT), but in other forms the profile can be implemented via a set of conditional statements, among other possibilities.FIG. 16depicts an embodiment in which the cancel delta2072profile is implemented as a set of conditional statements. A set of signals are provided to a conditional2082to determine whether to ignore2084the conditional2082, find an average grade2086of a vector of grade points (e.g. from the route grade profile), or find a maximum grade2088of the vector of grade points. A grade vector2090is provided along with a selector2092which determines how many points of the grade vector2090to utilize. Once the number of points from the grade vector2090are selected, the data is then provided to either a function that averages2094or finds the maximum2096of the vector. Depending on whether the grade information can be ignored, or whether the data should be averaged or the maximum determined, said data is then passed to a routine that calculates the value of the cancel delta.

Shown on the right side ofFIG. 16is a conditional block diagram that determines, based on the grade provided by the left side ofFIG. 16, whether the cancel delta2072should be set at the maximum2098, the minimum2100, or whether interpolation2102is required. The center conditional2104operates on basis of receiving values from either the max condition2106function structured to determine whether the max cancel delta should be used based on grade, or the min condition2108structured to determine whether the min cancel delta should be used based on grade. If neither of those conditions are met, the center conditional2104directs that the interpolation function2102should be used.

FIG. 17depicts yet another embodiment of the cancel delta2072which uses a combination of different sized windows of grade look-aheads. A grade look ahead vector2110is provided to a procedure2112which determines an equivalent grade of the vector2110, and a near horizon procedure2114which determines the average grade over a smaller subset, typically the near distance subset, of the grade look ahead vector2110. In one form the grade look ahead vector2110is 2 kilometer look-ahead vector, and the procedure2114examines merely the first 2108 m of the look-ahead vector. The equivalent grade procedure2112can take on any variety of forms, including an average of all datapoints.

The near horizon feature2114provides information to a conditional2116which determines whether the near horizon average grade meets a threshold conditional requirement. The conditional2116can be implemented such that it is satisfied if the near horizon average grade is greater than a threshold, but in other forms it can be implemented as an equal to or greater than condition.

Information from the conditional2116is provided to switch2118to determine whether the equivalent grade from procedure2112over the entire grade look ahead vector2110is ultimately passed to other procedures, or whether the near horizon average grade from procedure2114is used. If the near horizon average grade from procedure2114meets the condition of conditional2116, then a high cancel delta2120is used. Otherwise, a two-dimensional (2-D) LUT is used to determine the appropriate cancel delta.

As shown in block2122, a 2-D LUT has as inputs the vehicle mass as well as an adjusted equivalent grade which can be information from procedure2112. The 2-D LUT can have cross sections of cancel delta v. grade similar to that shown above inFIG. 15. The high cancel delta2120can be the same as a maximum cancel delta from any particular cross section of cancel delta v. grade.

An aspect of the present application provides a method comprising: operating a vehicle having an engine and a coasting management controller structured to disengage the engine from a driveline to allow a coasting event, computationally predicting a speed change of the vehicle as a result of an upcoming road condition upon which the vehicle is travelling, and requesting disengagement of the engine from the driveline if predicted speed change remains within a limit.

A feature of the present application provides wherein the limit is a calibratible threshold over a calibratible distance.

Another feature of the present application provides wherein the predicting a speed change occurs at a number of points in a window which includes upcoming terrain.

Still another feature of the present application further includes checking each point in the window against a limit.

Yet another feature of the present application provides wherein the number of points are regularly spaced in the window, and wherein the requesting disengagement of the engine includes inhibiting a signal that requests disengagement when the predicted speed change falls outside of the limit.

Still yet another feature of the present application further includes a persistence counter such that the requesting disengagement occurs after a time period has elapsed as a result of a persistence counter determining that predicted speed change remains within the limit.

Another aspect of the present application provides an apparatus comprising: a coasting management controller for a vehicle having an engine structured to provide motive power to the vehicle, the coasting management controller structured to: predict a future speed of the vehicle based upon a look-ahead road condition, and request disengagement of the engine from the driveline if predicted speed change remains within a speed limit.

A feature of the present application provides wherein the coasting management controller is structured to query the speed limit from a calibration table.

Another feature of the present application provides wherein future speed is determined at a number of discrete points within a window, the window including information of upcoming road grade.

Still another feature of the present application provides wherein the coasting management controller is structured to evaluate each point in the window against the limit.

Yet another feature of the present application provides wherein the limit is a fixed value over the entire window.

Still yet another feature of the present application provides wherein the controller further includes a persistence counter and a persistence threshold, the persistence counter counts the number of frames that the future speed remains within the limit, and wherein the controller is structured to delay the request for disengagement until the number of frames counted by the persistence counter meets the persistence threshold.

Yet another aspect of the present application provides an apparatus comprising: a vehicle having an internal combustion engine structured to provide motive power to a driveline, and a coasting management controller configured to regulate engagement of the engine with the driveline to allow for a coasting event, the coasting control system having a speed estimator structured to predict a future speed of the vehicle in light of upcoming road conditions, the coasting control system structured to request disengagement of the engine from the driveline if future speed remains within a speed limit.

A feature of the present application further includes a table that includes a plurality of values of limits from which the speed limit is determined, and wherein the coasting management controller is structured to query the speed limit from a calibration table.

Another feature of the present application provides wherein future speed is determined at a number of discrete points along a distance in front of the vehicle, the discrete points including information of upcoming road grade.

Still another feature of the present application provides wherein the coasting management controller is structured to evaluate each point in the window against the limit.

Yet another feature of the present application provides wherein the speed limit is a fixed value over the entire window.

Still yet another feature of the present application provides wherein the controller further includes a persistence counter and a persistence threshold, the persistence counter counts the number of frames that the future speed remains within the limit, and wherein the controller is structured to delay the request for disengagement until the number of frames counted by the persistence counter meets the persistence threshold.

Yet still another feature of the present application provides wherein the discrete points are evenly spaced.

A further feature of the present application provides wherein the discrete points are unevenly spaced.

An aspect of the present application includes a method comprising operating a vehicle including an engine that is disconnected to a driveline, monitoring speed of the vehicle and grade of terrain upon which the vehicle is operated through use of a vehicle speed controller, the vehicle speed controller structured to maintain disconnection of the engine from the driveline during a coasting event subject to a cancellation threshold speed beyond a desired speed in which the engine will be re-connected to the driveline, using grade of terrain in the vehicle speed controller to determine the cancellation threshold from a function that depends upon the grade of terrain, and comparing speed of the vehicle against the cancellation threshold to determine whether to re-connect the engine to the driveline.

A feature of the present application includes wherein the desired speed is a set speed of the vehicle speed controller, and wherein the cancellation threshold is a cancellation delta applied to a set speed of the vehicle speed controller.

Another feature of the present application includes wherein the cancellation threshold is determined from a cancel delta function that provides large cancellation threshold result at low grade and small cancellation threshold result at high grade.

Still another feature of the present application includes wherein the cancel delta function is based on a look ahead window having a first size, and which further includes a switch structured to operate on a basis of a grade information determined from a look ahead window having a second size smaller than the first size.

Yet another feature of the present application includes wherein the switch determines whether the cancellation threshold is determined from the cancel delta function or is a constant, the switch operated on the basis of comparing the grade information from the look ahead window having the second size against a threshold grade.

Still yet another feature of the present application includes wherein the cancellation threshold is determined from the function when the grade information from the look ahead window having the second size is below a threshold grade value.

Yet still another feature of the present application includes wherein the constant is a first constant value, wherein a value of the cancel delta function is a first function value, and wherein the first constant value is larger than the first function value.

A yet further feature of the present application includes wherein the cancel delta function is a function of grade information and vehicle mass.

Another aspect of the present application includes an apparatus comprising a speed based controller for a vehicle having a motor used to provide motive power to a driveline of the vehicle, the speed based controller structured to: issue a command to disconnect the driveline from the engine to begin a coasting event, monitor speed of the vehicle and grade of terrain upon which the vehicle is operated through use of a vehicle speed controller, and utilize the grade of terrain upon which the vehicle is operating to determine a cancel delta which represents a divergence speed from a set speed of the speed based controller within which the engine will remain disconnected from the driveline, but beyond which the engine is reconnected to the driveline.

A feature of the present application includes wherein the speed based controller includes a cancel delta function which provides the cancel delta, the cancel delta function structured to determine a value of the cancel delta upon receipt of the grade of terrain upon which the vehicle is operated.

Another feature of the present application includes wherein the cancel delta function provides a maximum value at a low grade, a minimum value at a high grade, and a linearly interpolated value between the maximum and minimum when at an intermediate grade between the low grade and the high grade.

Still another feature of the present application includes wherein the cancel delta function utilizes grade information determined from a switch, the switch structured to evaluate whether average grade in a look ahead window exceeds a pre-determined value.

Yet another feature of the present application includes wherein the switch determines whether the grade of terrain used in the cancel delta function is an average grade of a look ahead window for use in the cancel delta function or if a pre-determined value of the cancel delta is used.

Still yet another feature of the present application includes wherein the cancel delta function is a function of grade information and vehicle mass.

Yet another aspect of the present application includes an apparatus comprising a vehicle having an engine in selective engagement with a driveline, the engine providing power through the driveline to propel the vehicle when the engine is engaged with the driveline, a vehicle cruise control system configured to disengage the engine from the driveline during a coasting event, and to re-engage the engine with the driveline when a speed of the vehicle breaches a cancel delta threshold applied to a set speed of the vehicle cruise control system, the cancel delta threshold determined by providing a grade of terrain to a routine that calculates the cancel delta threshold as a function of grade of terrain.

A feature of the present application includes wherein the function used to calculate the cancel delta threshold is structured as a function of both grade of terrain and vehicle mass.

Another feature of the present application includes wherein the function is structured as a maximum value at a first grade value, a minimum value at a second grade value higher than the first grade value, and an interpolated value at a grade value intermediate the first grade value and the second grade value.

Still another feature of the present application includes wherein a switch determines the value of the grade of terrain based upon an average grade value of a look ahead vector of grade values.

Yet another feature of the present application includes wherein the switch selects a pre-determined constant value of the cancel delta threshold if the average grade value of a first look ahead vector of grade values exceeds a switch value.

Still yet another feature of the present application includes wherein the switch selects an average grade value of a second look ahead vector of grade values when the average grade value of a first look ahead vector is less than a switch value, the first look ahead vector of grade values is structured to look ahead a shorter distance than the second look ahead vector of grade values.