Patent Application
20180056979
The present disclosure relates to debounce timers for vehicles that may have a sport mode.
Shift by wire vehicles may include a lever arm to control transitions between vehicle modes. These vehicle modes may include drive, reverse, park, neutral, and sport. The mode may determine a direction of travel for the vehicle or performance characteristics.
In hybrid vehicles, the control system of the vehicle may choose to start or stop a combustion engine based on a variety of factors. These factors may include the selected mode. In many shift by wire vehicles, the lever arm may pass through various modes during the transition between the original mode selection and the final mode selection. For example, a vehicle occupant may actuate the shifter to transition from park to drive and momentarily select reverse and neutral. The transitory selection of these modes may impede the proper application of control logic for the engine stops and starts.
A vehicle may include a controller programmed to start an engine based on a brake status before and during a mode change, and expiration of a timer initiated upon completion of the mode change and having a duration based on a learned mean mode-specific shift time window. The engine may be started in response to a request to change modes. A mean mode-specific transition period may be based on aggregated user data. A pre-change mode may be a Sport mode. A post-change mode may be a reverse driving mode.
Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
Hybrid electric vehicles reduce emissions by minimizing the use of fossil fuels. Other vehicles may reduce fossil fuel consumption. For example, mild-hybrid and micro-hybrid vehicles may sporadically start and stop the engine to reduce fuel consumption and improve emissions. Control schemes are implemented to start and stop these engines based on various factors. For example, an engine may be started to charge a battery or provide additional motive power. If the vehicle is placed in park while the engine is running, the control scheme may instruct the controller to stop the engine. As another example, a control scheme may instruct the controller to stop the engine when the vehicle is in a neutral mode. Under certain conditions, the control scheme may instruct the controller to start the engine or maintain the engine in a running state in the reverse gear or drive gear. A vehicle occupant may move the lever from reverse to drive. The typical P-R-N-D configuration may cause the controller of particular hybrid vehicles to toggle the engine state as the lever passes through the neutral mode, as discussed above.
A debouncing delay timer may be implemented to prevent unwanted engine start and stop cycles when the mode-shift lever is transitioning between original and desired modes. The debouncing delay timer may be set for a specific, static time window. A static time window may cause unintended consequences. For example, certain vehicles may have longer transition distances. Meaning, the distance between each driving mode may be inconstant. Inconstant distances may give rise to varying transition times between particular driving modes. Variable transition times may hinder the effectiveness of the static time window. For example, Vehicle A may have a larger interior and mode shifter than Vehicle B. The larger shifter may have a longer transition time from drive to park. If both vehicles have the same static time window, the smaller vehicle may have too long of a static time window, or the time window may be ineffective for the larger time window. In a similar vein, vehicles having identical mode shifters may require dynamic time windows. For example, Vehicle A may be driven by predominantly slow shifters, and Vehicle B may be driven by predominantly fast shifters. A dynamic time window may be tuned to ensure proper start and stop behavior from the control system.
In general, vehicles have mode shifters with four modes as discussed above. The addition of a fifth mode creates an additional layer of complexity to debouncing delays and control system behavior. A drive mode and sport mode may be collectively considered a forward drive mode. A start and stop control system with a sport mode option may change the start and stop triggers. For example, an engine may be left running in a sport mode to increase performance. An engine may be stopped in a normal mode under similar circumstances to conserve fuel consumption. The change in start and stop triggers may also impact the debouncing delay timer. A static window may be inadequate in providing the proper control system inhibition when the two use modes are available.
A dynamic time window may be determined based on aggregated data from users. A vehicle information system may be implemented to send data off board to a cloud server. The cloud server may receive mode shifter use data and store it in a database. The data may include information related to the time history of each mode change. As the shifter is placed in each particular mode, a time stamp may be recorded with the change. The server may aggregate all of the shifts from a given direction. For example, the server may find the average transition time from drive to neutral and neutral to drive. The information system may create a mode-shift transition time series to retain and determine the intended target mode. For example, the system may recognize that when transitioning from park to drive the shifter traverses through reverse and neutral as well. As the average shift time windows are calculated for the particular vehicle model or shifter configuration, the start and stop control scheme may be updated with new debounce timings to ensure unnecessary toggling does not occur.
The start and stop control scheme may take brake status, before, during, and after the shift, into account. The brake status may be indicative of the energy requested to operate the vehicle. For example, a brake applied before the shift and released after or during the shift may indicate intent to use increased energy after the shift. Under these circumstances, the controller may start the engine to anticipate the increased consumption of energy. The controller may also anticipate a reduction in energy consumption. While shifting to certain gears, application of the brake after the shift may indicate intent to reduce energy consumption. The controller may anticipate the reduction by stopping the engine. Anticipation by the controller may take into consideration the status of the time window. For example, the controller may base the start and stop of the engine on the pre and post brake status, the mode shift, and the expiration of the time window.
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The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
