Powertrain control apparatus for improving fuel economy

Apparatus for selecting an active gear ratio in a gearbox which has a choice of various discrete gear ratios available to function as said active gear ratio by transferring mechanical power from a power output shaft of a combustion engine to a power output shaft of the gearbox, the engine having a current value of modified fuel flow rate that applies to operation when (a) the power as delivered to a load by said gearbox output shaft has a value which is current, (b) said gearbox output shaft is operating at its current rotational speed and (c) the gearbox is transferring power from the engine to the load using one of said choice of gear ratios which is currently said active gear ratio, said modified fuel flow rate being a product of brake specific cost of engine operation and power concurrently developed by the engine for delivery to the load, and said brake specific cost of engine operation comprising mass amount of fuel consumed by the engine in producing one brake-horsepower-hour of mechanical energy for delivery to the load, the apparatus comprising:

• first means operative to identify a tentatively better one of said choice of gear ratios which is different from said currently active gear ratio, the engine having an improved value of said modified fuel flow rate that applies to operation when (a) the power as delivered to the load by said gearbox output shaft has said current value, (b) said gearbox output shaft has said current value of rotational speed and (c) the gearbox is transferring power from the engine to the load using said tentatively better gear ratio, said improved value of modified fuel flow rate being numerically less than said current value of modified fuel flow rate by a sacrifice in fuel flow rate,
• second means operative to reduce said sacrifice in fuel flow rate by implementing at separate iterations each of (a) refraining from selecting said tentatively better gear ratio to replace said currently active gear ratio for transferring power from the engine to the load to thereby initiate a period of waiting for said sacrifice in fuel flow rate to inherently decrease due to changes in factors comprising magnitude of the power as delivered to the load and rotational speed of said gearbox output shaft, a decrease to zero in said sacrifice in fuel flow rate before expiration of said waiting period causing an accumulation of values over said waiting period to be reset to an initial value, (b) refraining from selecting said tentatively better gear ratio to replace said currently active gear ratio to thereby continue said waiting period, said waiting period being limited in duration by a threshold for said accumulation of values, said accumulation approaching said threshold at a rate generally greater when said sacrifice in fuel flow is relatively large, and (c) selecting said tentatively better gear ratio to replace said currently active gear ratio when said accumulation of values reaches said threshold,
• and third means operative to repeatedly activate said first and said second means to thereby generate said iterations and to thereby cause said accumulation of values over said waiting period,
• whereby said sacrifice in fuel flow rate is reduced, but not without regard for the average frequency of gearshifts.

Apparatus for improving the efficiency with which mechanical power is produced by a combustion engine and delivered through a discrete-ratio gearbox to a load, the engine having torque control means (a) comprising at least one engine control device and (b) used to provide substantially all regulation of brake torque produced at a power output shaft of the engine for delivery to the gearbox, the engine having means operative to automatically regulate mass consumption rate of fuel by the engine according to a calibration which depends on both of operating speed of said engine power output shaft and status of said engine torque control means, and the engine having in conjunction with said fuel consumption calibration a topographical data surface of brake specific cost of engine operation on an area defined by operating speed of said engine power output shaft and by a wide range of the power produced by the engine, said brake specific cost of engine operation comprising mass amount of said fuel consumed by the engine in producing one brake-horsepower-hour of mechanical energy for delivery to the to the load and minimization of said brake specific cost of engine operation on said topographical surface of brake specific cost yielding an uninterrupted schedule of operating speed of said engine power output shaft over said wide range of the power produced by the engine, the apparatus comprising:

• first means for storing performance data, all of said uninterrupted schedule of minimum brake specific cost being reproducible with good accuracy from a constant multiplying factor and data consisting of said performance data stored by said first means,
• and second means operative to repeatedly perform a comparison of different ones of a choice of gear ratios made available by the gearbox for transferring the power from the engine to the load, each iteration of said comparison of gear ratios utilizing a candidate data value retrieved from said stored performance data for each of said different ones of said available gear ratios, each one of said candidate values being associated with a particular one of said choice of gear ratios and being current for steady-state power produced by the engine and accurate for operating speed of the engine which produces current operating speed of the load using said particular gear ratio said steady-state power level, and said comparison of gear ratios including selection of one of said different gear ratios which is best from the standpoint of minimizing said brake specific cost of engine operation,
• whereby gear ratios are selected to thereby improve fuel economy.

Apparatus for enhancing selection of an active gear ratio in a gearbox which has a choice of various discrete gear ratios available to function as said active gear ratio by transferring mechanical power from a power output shaft of a combustion engine to a power output shaft of the gearbox, the apparatus comprising:

• first means containing at least one stored array of data which yield a performance parameter when addressed at particular values indicative of an operative speed and a power level, said performance parameter being selected from a parameter indicative of brake specific cost of engine operation and a parameter indicative of a difference in said brake specific cost of engine operation, said brake specific cost of engine operation comprising mass amount of fuel consumed by the engine in producing one brake-horsepower-hour of mechanical energy for delivery to a load driven by said gearbox output shaft,
• second means operative to use a measurement to obtain at least one of said particular value indicative of operating speed as used to address said at least one stored array of data,
• third means operative to provide said particular value indicative of a power level as used to address said at least one stored array of data, said power level being substantially equal during steady-state operation of the engine to power being delivered to said load from said gearbox power output shaft,
• and fourth means operative to repeatedly determine an indicator for an actual magnitude of improvement currently being made available in said brake specific cost of engine operation by a gearshift from one of said choice of gear ratios that is currently said active gear ratio to a different one of said choice of ratios, said indicator of improvement being determined by said fourth means using procedures comprising using said particular values indicative of speed and power from said second and said third means respectively to address said at least one array of data stored by said first means to thereby obtain at least one current value of said performance parameter,
• whereby said indicator of improvement facilitates an enhanced compromise between minimizing said brake specific cost of engine operation and reducing the average frequency of gearshifts.

Apparatus for improving the efficiency with which a combustion engine powers a motor vehicle through a transmission which has a choice of different forward speed ratios available for coupling a power output shaft of the engine to a power output shaft of the transmission, the engine having (1) torque control means which (a) comprises at least one engine control device and (b) is used to provide substantially all regulation of brake torque produced at said engine power output shaft and (2) means operative to automatically regulate mass consumption rate of fuel by the engine to a schedule which depends on both of operating speed of said engine output shaft and status of said engine torque control means, the apparatus comprising:

• first means for storing data,
• second means operative to use said first means to identify upshifts for the transmission substantially according to a transmission shift map of said choice of forward speed ratios, said transmission shift map being on an area defined by (1) magnitude of power substantially as delivered by said transmission output shaft for propelling the vehicle and (2) operating of said transmission output shaft, each one of said choice of forward speed ratios having in conjunction with performance of the engine as established by said engine fuel consumption schedule a topographical map of brake specific cost of engine operation on said area of said transmission shift map, said brake specific cost of engine operation comprising mass amount of fuel consumed by the engine in delivering one brake-horsepower-hour of mechanical energy to said transmission output shaft and each individual point on said transmission shift map (a) having associated therewith particular values of said operating speed of said transmission output shaft and of said magnitude of power as delivered by said transmission output shaft and (b) being associated by said transmission shift map with one of said choice of forward speed ratios which has a candidate value of said brake specific cost of engine operation at least as low as that of any other of said choice of forward speed ratios which are capable of allowing the engine to establish said particular values of transmission output shaft speed and power, each example of said choice of speed ratios which are capable of establishing said particular values of speed and power having its candidate value of said brake specific cost of engine operation obtained from (1) a specific one of said topographical maps of brake specific cost which applies to said example speed ratio and (2) a location on said specific topographical map determined particular values of transmission output shaft speed and power,
• and third means operative to use said second means in selecting upshift for said transmission, at least some upshifts of the transmission being selected by said third means with a discrepancy relative to their identification in accordance with said transmission shift map, said discrepancy having at least a strong correlation to acceleration of the motor vehicle and said discrepancy being selected from (1) a significant time delay imposed between identification according to said transmission shift map and selection by said third means, duration of said time delay being reduced as acceleration of the motor vehicle increases, and (2) preemptive selection by said third means prior in time to identification according to said transmission shift map, said preemptive selection being at least strongly correlated to acceleration of the motor vehicle which is great enough in magnitude to ensure continued acceleration of the motor vehicle after execution of an upshift associated with said preemptive selection,
• whereby selection of upshifts identified according to said transmission shift map contributes to reduced fuel consumption of the engine.