Method for estimating the torque of a heat engine

Patent metadata

Field	Value
Publication number	US-10612988-B2
Application number	US-201515321267-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	Jun 24, 2014
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A method estimates a torque of a heat engine in a vehicle hybrid transmission including at least a heat engine and an electric machine together or separately supplying a heat engine torque and heat engine torque intended for wheels of the vehicle. The method uses a measurement of a speed of the heat engine, a value of the heat engine torque reference, and a value of the electric machine torque. The method also sums an estimate of a total torque supplied by the transmission to the wheels and of an estimate of an equivalent resistive torque of the transmission to determine the estimated heat engine torque.

First claim

The invention claimed is:

1. A method for controlling a torque of a heat engine of a vehicle hybrid transmission including at least the heat engine and an electric machine supplying a torque of the heat engine and the electric machine to wheels of the vehicle, comprising:
measuring a speed of the heat engine, a reference torque of the heat engine, and the torque of the electric machine;
estimating a total torque supplied by the transmission;
estimating an equivalent resistive torque of the transmission to obtain an estimated equivalent resistive torque of the transmission, wherein the estimated equivalent resistive torque of the transmission is obtained by assigning a gain M 1 a sign of an integration x 1 and then multiplying by an inverse of a gain k 2 , then integrating, then multiplying by an inverse of an engine time constant τ, then integrating, then multiplying by a parameter α, the parameter α being dependent on stepdown gear ratios of a gearbox and an axle assembly of the vehicle;
estimating the torque of the heat engine by summing the estimated total torque supplied by the transmission and the estimated equivalent resistive torque of the transmission; and
controlling the torque of the heat engine based on the estimated torque of the heat engine and the reference torque of the heat engine.

2. The method for controlling the torque of the heat engine as claimed in claim 1 , wherein a transmission equivalent inertia with respect to the heat engine is determined from a relationship of the type
J eq_th {dot over (ω)} th =T th +αT em −βT eq res , where

a parameter α is dependent on stepdown gear ratios between a heat engine shaft and the wheels,
T th is the torque of the heat engine,
T em is the torque of the electric machine,
ω th is the speed of the heat engine,
T eq res is the equivalent resistive torque of the transmission, and
J eq-th is the transmission equivalent inertia with respect to the heat engine.

3. The method for controlling the torque of the heat engine as claimed in claim 2 , wherein an estimate of the speed of the heat engine is obtained from an integrated term, the integrated term being an integration of the torque of the electric machine multiplied by the parameter α, and a drift compensation being assigned a sign of a difference of the measurement of the speed of the heat engine and the estimate of the speed of the heat engine.

4. The method for controlling the torque of the heat engine as claimed in claim 3 , wherein the integrated term is corrected in a loop by an inverse of the transmission equivalent inertia with respect to the heat engine.

5. The method for controlling the torque of the heat engine as claimed in claim 3 , wherein the drift compensation assigned the sign of the difference of the measurement of the speed of the heat engine and the estimate of the speed of the heat engine is multiplied by the inverse of a gain k 1 , and corrected with a result of the integration x 1 .

6. The method for controlling the torque of the heat engine as claimed in claim 5 , wherein the estimate of the total torque is obtained by integrating the reference torque of the heat engine and the gain M 1 assigned the sign of the integration x 1 .

7. A method for controlling a torque of a heat engine of a vehicle hybrid transmission, comprising:
measuring a speed of the heat engine, a reference torque of the heat engine, and a torque of an electric machine;
estimating a total torque supplied by the transmission, an equivalent resistive torque of the transmission, and a speed of the heat engine, wherein the estimated speed of the heat engine is corrected in a loop by an inverse of a transmission equivalent inertia with respect to the heat engine, and wherein the estimated equivalent resistive torque of the transmission is obtained by assigning a gain M 1 a sign of an integration x 1 and then multiplying by an inverse of a gain k 2 then integrating, then multiplying by an inverse of an engine time constant τ, then integrating, then multiplying by a parameter β, the parameter β being dependent on stepdown gear ratios of a gearbox and an axle assembly of the vehicle;
estimating the torque of the heat engine by summing the estimated total torque supplied by the transmission and the estimated equivalent resistive torque of the transmission; and
controlling the torque of the heat engine based on the estimated torque of the heat engine.

Assignees

• Renault Sas
• Nissan Motor

Inventors

• Maloum Abdelmalek

Classifications

• B60W2510/1095

  Inertia · CPC title

• B60W2510/0695

  Inertia · CPC title

• F02D41/023 Primary

  in relation with the gear ratio shifting (conjoint control for improving gear change B60W30/19) · CPC title

• B60W40/1005

  Driving resistance · CPC title

• F02D2200/1004

  Estimation of the output torque · CPC title