Method for determining an output torque in a drive system capable of being power shifted in a vehicle

Abstract

A method for determining an output torque in a drive system capable of being power shifted in a vehicle includes providing the drive system having a drive unit for transmitting the drive torque, a dual clutch having a first clutch and a second clutch, and a power shift transmission. The power shift transmission has a first gear with a first gear ratio and a second gear with a second gear ratio. The method also includes measuring a first torque transmitted by the first clutch, calculating a distribution of the drive torque to the first clutch and the second clutch using the first torque, and determining the output torque from the distribution of the drive torque.

Claims

1. A method for determining an output torque in a drive system capable of being power shifted in a vehicle, comprising: providing the drive system comprising: a drive unit for transmitting a drive torque; a dual clutch comprising a first clutch and a second clutch; and a power shift transmission comprising: a first gear with a first gear ratio; and a second gear with a second gear ratio; measuring a first torque transmitted by the first clutch; calculating a distribution of the drive torque to the first clutch and the second clutch using the first torque; and determining the output torque from the distribution of the drive torque.

2. The method of claim 1, wherein the first torque is measured at an output of the first clutch.

3. The method of claim 1, wherein the first torque is measured between the first clutch and the power shift transmission.

4. The method of claim 1 further comprising calculating a second torque transmitted by the second clutch from the first torque and the drive torque.

5. The method of claim 4 wherein the drive torque is measured or estimated.

6. The method of claim 4, wherein the output torque is determined from a sum of: the first torque multiplied by the first gear ratio; and the second torque multiplied by the second gear ratio.

7. The method of claim 1 wherein the drive system further comprises: a single wheel drive; or an axle drive, which drives only one axle or one wheel, or a dual wheel combination of the vehicle.

8. The method of claim 7 wherein the drive system comprises a plurality of single wheel drives or axle drives.

9. The method of claim 1 wherein the drive unit is an electrical machine or an internal combustion engine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure allows for numerous embodiments. One of these will be explained in more detail with reference to the FIGURE shown in the drawing.

(2) In the FIGURE:

(3) the single FIGURE shows an exemplary embodiment of the method according to the disclosure.

DETAILED DESCRIPTION

(4) The single FIGURE shows an exemplary embodiment of the method according to the present disclosure on a drive system 1 of a vehicle. The drive system 1 has a first and a second clutch 2, 3, downstream of which a power shift transmission is connected. This power shift transmission is characterized in FIG. 1 by two gear ratios i1 and i2 of the power shift transmission. The gear ratio i1 is downstream of the clutch 2 and the gear ratio i2 is downstream of the clutch 3. A torque source 4 in the form of a drive unit, such as an electric motor or an internal combustion engine or an electric motor and an internal combustion engine, generates a drive torque MQ, which is distributed to the clutches 2 and 3.

(5) In the closed state, the first clutch 2 is connected to a transmission input shaft 5 in a torque-transmitting manner, while the second clutch 3, when it is closed, is coupled to a second transmission input shaft 6 in a torque-transmitting manner. Since the clutches 2, 3 are selectively switchable, either the first transmission input shaft 5 transmits the torque MK1 of the first clutch 2 or the second transmission input shaft 6 transmits the torque MK2 of the second clutch 3 to the transmission with the respective gear ratios i1, i2. The torques MK1 and MK2 are brought together behind the transmission and act as output torque MA on a wheel 8 or an axle of the vehicle. In this case, the drive system 1 forms a single-wheel drive or an axle drive.

(6) In order to determine the output torque MA inexpensively and with little software expenditure, only the torque MK1 of the first clutch 2 is measured. The measurement takes place between the output of the first clutch 2 and the transmission (gear ratio i1). The measured torque MK1 is fed to a logic unit 7, which calculates the torque MK2 of the second clutch 3 with the aid of the drive torque MQ and the measured torque MK1. For this purpose, the current drive torque MQ is estimated or measured and also fed to the logic unit 7. This is carried out with the necessary ASIL classification.

(7) The following applies

(8) $\begin{array}{cc}MK2=\mathrm{MQ}-\mathrm{MK}1& \left(E1\right)\end{array}$
Since the gear ratios i1, i2 of the transmission are known, the output torque MA on the wheel 8 or the axle is determined as follows:

(9) $\begin{array}{cc}\mathrm{MA}=\mathrm{MK}1*i1+\mathrm{MK}2*i2& \left(E2\right)\end{array}$

(10) In this way, the output torque MA is determined by means of only one torque measurement on one of the two clutches 2, 3.

REFERENCE NUMERALS

(11) 1 Drive system

(12) 2 Clutch

(13) 3 Clutch

(14) 4 Torque source

(15) 5 First transmission input shaft

(16) 6 Second transmission input shaft

(17) 7 Logic unit

(18) 8 Wheel/axle