Search

EP-4737167-A1 - METHOD FOR SMOOTHING THE CHANGE FROM AN ELECTRIC TRACTION MODE TO A HYBRID TRACTION MODE IN A HYBRID VEHICLE

EP4737167A1EP 4737167 A1EP4737167 A1EP 4737167A1EP-4737167-A1

Abstract

Method for smoothing the change from an electric traction mode to a hybrid traction mode in a hybrid vehicle, comprising the steps of: receiving traction mode information (S1) evaluating (S2) the convenience of changing to a first hybrid traction mode (H x ) by measuring current values of predefined operating parameters; evaluating (S3) the convenience of shifting -within a predefined lapse of time- to a second hybrid powertrain (H x+1 ) corresponding to a higher speed range, and if so, calculating the remaining time (T) for changing to the second hybrid powertrain (H x+1 ); and modifying the energy management law (LGE) for making the gearbox control unit change directly from the electric powertrain (EV x ) to the second hybrid powertrain (H x+1 ), once said remaining time (T) has lapsed.

Inventors

  • KEMPSKI, Paul
  • JOUSSET, Corentin

Assignees

  • Horse Powertrain Solutions, S.L.U.

Dates

Publication Date
20260506
Application Date
20241031

Claims (6)

  1. Method for smoothing the change from an electric traction mode to a hybrid traction mode in a hybrid vehicle provided with a gearbox control unit, the gearbox control unit being arranged for selecting a target powertrain for each instant, according to a predefined energy management law (LGE) which assigns a score to each powertrain of the hybrid vehicle for each instant, the method being characterized in that it comprises the steps of: a) receiving (S1) the current engaged powertrain of the hybrid vehicle; b) if the current engaged powertrain corresponds to a hybrid traction mode, then let the gearbox control unit act according to the predefined energy management law (LGE) and conversely, if the current engaged powertrain corresponds to an electric mode, then evaluating (S2) the convenience of changing to a hybrid traction mode associated to a first hybrid powertrain (H x ), by measuring current values of predefined operating parameters of the hybrid vehicle and comparing them with a first set of predefined reference ranges; c) if at least one of said measured values is outside the first set of predefined reference ranges, then let the gearbox control unit act according to the predefined energy management law (LGE) and conversely, if all measured values are within the first set of predefined reference ranges, then evaluating the convenience (S3) of shifting -within a predetermined time interval- to a second hybrid powertrain (H x+1 ), corresponding to a higher speed range than the first hybrid powertrain (H x ), by comparing measured values of said operating parameters, with a second set of predefined reference ranges; d) if at least one of said measured values is outside the second set of predefined reference ranges, then let the gearbox control unit act according to the predefined energy management law and conversely, if all measured values are within the second set of predefined reference ranges, then calculating (S4) the remaining time (T) for changing to the second hybrid powertrain (H x+1 ); and e) modifying (S5) the energy management law, so that the score of the current engaged powertrain is higher than the score of the first hybrid powertrain (H x ) and so that immediately after the remaining time has lapsed, the score of the second hybrid powertrain (H x+1 ) becomes the highest of all powertrains of the electric vehicle so it becomes the target powertrain.
  2. Method according to claim 1, wherein the step (S3) of evaluating the convenience of shifting -within a predetermined time interval- to a second hybrid powertrain (H x+1 ), corresponding to a higher speed range than the first hybrid powertrain (H x ), also involves calculating the energetic costs of the current engaged powertrain, the first hybrid powertrain (H x ) and the second hybrid powertrain (H x+1 ), the energetic costs being calculated as the Hamiltonian of the corresponding powertrain, step (S3) also comprising comparing the values of the Hamiltonians obtained.
  3. Method according to any previous claim, wherein the first set of predefined reference ranges, comprises reference ranges of at least one of the following operating parameters of the hybrid vehicle: - vehicle speed; - vehicle longitudinal acceleration; - physical position of the accelerator pedal within its stroke; - braking activation information; - selected driver profile; - selected energy management mode; - energy equivalence factor, establishing a link between fossil consumption and mechanical energy consumption; - list of current available powertrains; - energy costs for selecting each powertrain; - current engaged powertrain; and - target powertrain.
  4. Method according to any previous claim, wherein the second set of predefined reference ranges, comprises reference ranges of at least one of the following operating parameters of the hybrid vehicle: - vehicle speed; - vehicle longitudinal acceleration; - physical position of the accelerator pedal within its stroke; - braking activation information; - selected driver profile; - selected energy management mode; - list of current available powertrains; and - target powertrain.
  5. Computer readable medium, characterized in that it comprises instructions that, when executed in a computer, cause the computer to carry out a method for smoothing the change from an electric traction mode to a hybrid traction mode in a hybrid vehicle, according to any of claims 1 to 4.
  6. Traction management unit for a hybrid vehicle, said unit comprising programmable logic means configured for carrying out a method for smoothing the change from an electric traction mode to a hybrid traction mode, according to any of claims 1 to 4

Description

Technical field The present invention belongs to the automotive technical field, and more particularly to the area of traction management of hybrid vehicles, such as, for example and without being limitative, hybrid cars, vans, trucks and buses. Thus, a first object of this invention is a method for smoothing the change from an electric traction mode to a hybrid traction mode, in a hybrid vehicle, which can avoid quick and unpleasant changes between different reducer gears responsible for the connection of the combustion engine to, at least, one tractor wheel. The present invention also refers to a computer readable storage medium comprising instructions which, when executed in a computer, cause the computer to carry out the abovementioned change smoothing, and to a traction management unit for a hybrid vehicle comprising programmable logic means capable of performing said change smoothing method. Background of the invention Hybrid vehicles are generally provided with a combustion engine and at least one electric drive machine, jointly forming a so-called hybrid engine, which is connected -at least- to one tractor wheel of the vehicle through a plurality of reducer gears. Examples of these hybrid engines are disclosed, among other documents, in document FR3022495 corresponding to patent application FR1455850 filed by Renault SAS, which describes hybrid engines having one combustion engine and two electric drive machines. Several different traction modes could be adopted by the hybrid engine during its operation, and particularly: a hybrid traction mode, in which the combustion engine is connected to the tractor wheel(s) through a first hybrid-thermal reducer gear, according to a first transmission ratio and at least one electric drive machine is connected to the tractor wheel(s), through a first electric reducer gear according to a second transmission ratio;an electric traction mode, in which the electric drive machine is connected to the tractor wheel(s) through the first electric reducer gear, according to a third transmission ratio; anda thermal traction mode, in which only the combustion engine is connected to the tractor wheel(s) through the first hybrid-thermal reducer gear, according to a fourth transmission ratio. The first two traction modes listed above (i.e. the hybrid traction mode and the electric traction mode) contribute to reducing fuel consumption of the combustion engine. More particularly, during the hybrid traction mode, the combustion engine and at least one electric drive machine ensure the traction of the vehicle with parallel operation of these components via the corresponding reducer gears. Consequently, multiple transmission ratios between the corresponding elements which make up the powertrain, could be chosen during the hybrid traction mode. On the other hand, during the electric traction mode, the required vehicle traction is achieved only by means of the electric drive machine(s), thus allowing the combustion engine to be unused and therefore switched off. In order to manage hybrid or electric traction state change requests, most of the traction management systems which are currently employed by hybrid vehicles, make the corresponding decisions based on a function generally known as "Energy Management Law" (LGE, French acronym for "Loi de Gestion de I'Energie"). The LGE has, among others, the role of optimizing the vehicle's consumption and to that end, it creates an optimal classification (by means of a score or ranking), intended to favor certain hybrid or electric traction modes among all the existing ones, in order to define a final target powertrain for the operation of the vehicle. Throughout the present description, it should be understood that the expression "powertrain" refers to the arrangement of all the mechanical elements (heat engine's crankshaft, drive shafts, transfer shafts, reducer gears, etc.) required for generating a particular traction mode of the electric vehicle. Letter "H" will be used for hybrid powertrains (that is, powertrains implementing hybrid traction modes), "Th" will be used for thermal powertrains (i.e., powertrains implementing thermal traction modes) and "EV" for electric powertrains (powertrains implementing electric traction modes). The optimal classification employed by current traction management systems is usually based, among others, on the following criteria: compliance with certain pleasure constraints, such as, for example: NVH (acronym of "noise, vibration and harshness"), and thermal comfort;the so called "driver's will", i.e., the desired target torque at the wheels, which is obtained, for example, from stepping on the accelerator with a certain intensity causing the pedal to move to a certain position within its stroke; andthe current state of energy in the electric battery and the energy target of said battery. Said ranking is calculated instantaneously and therefore, this implies that it must be continuously re-evaluated by th