US 8,010,264 B2Granted

Control device for a hybrid electric vehicle

AssigneeMitsubishi Fuso Truck and Bus Corporation

InventorsMakoto Ogata, Tatsuo Kiuchi

Life of this patent

Estimating the term…

Loading patent…

Abstract

A hybrid electric vehicle is arranged such that a driving force of an engine and a driving force of an electric motor can be transmitted to driving wheels through an automatic transmission having a plurality of forward gears. When it is detected that the vehicle is in a predetermined state in which it is difficult for the electric motor to output an upper limit torque predetermined as a generable maximum torque, a vehicle ECU controls the automatic transmission using a gear shift map configured such that the automatic transmission is downshifted earlier in accordance with a change in the operating state of the vehicle and upshifted later in accordance with a change in the operating state of the vehicle in comparison with a gear shift map that is used when it is not detected that the vehicle is in the predetermined state.

Claims6

Dependent claims

A control device for a hybrid electric vehicle arranged such that a driving force of an engine and a driving force of an electric motor can be transmitted to driving wheels through an automatic transmission having a plurality of forward gears, the control device comprising:

an output limiting unit that limits a generable torque of the electric motor to a limited torque that is lower than an upper limit torque predetermined as a generable maximum torque of the electric motor;
an output limit detection unit that determines whether or not the output limiting unit actually limits the generable torque of the electric motor to the limited torque;
and
a control unit that controls the automatic transmission to upshift a forward gear according to an increase of running speed of the vehicle and downshift the forward gear according to a decrease of the running speed of the vehicle based on a gear shift map, wherein
when the output limit detection unit determines that the generable output torque of the electric motor is not limited to the limited torque by the output limiting unit, the control unit controls the automatic transmission using a first shift map as the gear shift map, and, when the output limit detection unit determines that the generable output torque of the electric motor is limited to the limited torque by the output limiting unit, the control unit controls the automatic transmission using a second shift map as the gear shift map, the second shift map being set so that an upshift is carried out on a higher speed side as compared with a corresponding upshift carried out by using the first shift map and a downshift is carried out on a higher speed side as compared with a corresponding downshift carried out by using the first shift map.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/717,643Filed 14 Mar 2007
Priority: JP 2006-06890014 Mar 2006
Published: US 2007/0216312 A120 Sep 2007
Granted: 30 Aug 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

B60W 20/30
Control systems specially adapted for hybrid vehicles: control strategies involving selection of transmission gear ratio
B60K 6/48
Characterised by the architecture of the hybrid electric vehicle: parallel type
B60W 10/06
Including control of propulsion units: including control of combustion engines
B60W 10/08
Including control of propulsion units: including control of electric propulsion units, e.g. motors or generators