Shift control device for hybrid vehicle

• US 6,819,985 B2
• Filed: 02/28/2003
• Issued: 11/16/2004
• Est. Priority Date: 03/13/2002
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd., Renault Sas (Renault)
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Pichon, Yves, Oshidari, Toshikazu, Kargar, Keyvan, Minagawa, Yuusuke
• Primary Examiner(s): Black, Thomas C.
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US10/375,347
• Publication Number:
  US 20030176955A1
• Time in Patent Office: 627 Days
• Field of Search: 701/22, 180/65.3, 180/65.1, 180/65.6, 180/65.4, 318/9, 318/139, 318/432, 318/8, 318/13, 322/7, 322/16, 322/40, 290/40.B, 290/40.C, 290/40.F
• US Class Current: 701/22
• CPC Class Codes: B60K 2006/262 the motor or generator are used as clutch, e.g. between engine and driveshaft
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/448 Electrical distribution type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/086 Power
• CPC Class Codes: B60W 2710/1061 Output power
• CPC Class Codes: F16H 2037/103 Power split variators with each end of the CVT connected or connectable to a Ravigneaux set
• CPC Class Codes: F16H 2037/106 with switching means to provide two variator modes or ranges
• CPC Class Codes: F16H 3/727 : with at least two dynamo electric machines for creating an electric power path inside the gearing, e.g. using generator and motor for a variable power torque path special adapted for a hybrid electric vehicle B60K6/20
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/914 : Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/919 : Stepped shift
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/951 : Assembly or relative location of components

Abstract

A shift control device includes a controller and a differential mechanism including four rotating elements. Each of the elements is connected to an engine, two motor/generators and an output. The controller is programmed to calculate a target driving power; make a judgment as to whether the target driving power is less than or equal to a driving power wherein the engine is driven under optimum fuel efficiency; when the judgment shows that the target driving power is larger than the driving power, calculate an engine'"'"'s speed and torque wherein the target driving power is realized such that the engine is driven for maximum load; and control the engine under the engine'"'"'s speed and torque.

Claims

1. A shift control device for a hybrid vehicle comprising:

a differential mechanism including at least four rotating elements whose rotating states are determined by rotating states of two of the at least four rotating elements, wherein the elements connect a driving source, two motor/generators and an output; and

a controller programmed to;

calculate a target driving power based on a driving condition;

make a first judgment as to whether the target driving power is less than or equal to a first driving power corresponding to an operating region wherein the driving source is driven under optimum fuel efficiency;

when the first judgment shows that the target driving power is larger than the first driving power, calculate a first driving source speed and a first driving source torque corresponding to an operating region wherein the target driving power is realized such that the driving source is driven under maximum load and control the driving source at the first driving source speed and the first driving source torque.

2. A shift control device for a hybrid vehicle as claimed in claim 1, wherein the controller is further programmed to:

calculate each of motor/generator torque and rotating speed based on the first driving source speed and torque, the current output speed and the target driving power; and

control motor/generators at calculated torque and rotating speed, respectively.

3. A shift control device for a hybrid vehicle as claimed in claim 1, wherein the first driving power under optimum fuel efficiency is a value when the driving source is driven on an operating point that should be obtained when the driving source is driven under optimum fuel efficiency based on the current output rotating speed.

4. A shift control device for a hybrid vehicle as claimed in claim 1, wherein the driving source is an engine.

5. A shift control device for a hybrid vehicle as claimed in claim 1, wherein the differential mechanism is a Ravigneawx planetary gear set.

6. A shift control device for a hybrid vehicle as claimed in claim 5, wherein the Ravigneawx planetary gear set may be represented as a lever analogy diagram, and the driving source, the two motor/generators and the output are arranged on the lever analogy diagram in the following order:

a first motor/generator, the driving source, the output, a second motor/generator.

7. A shift control device for a hybrid vehicle as claimed in claim 6, wherein the Ravigneawx planetary gear set includes five rotating elements, and the five elements are connected to the first motor/generator, the driving source, the output, a brake and the second motor/generator, and arranged on the lever analogy diagram in the following order:

the first motor/generator, the driving source, the output, the brake and the second motor/generator; and

the controller is further programmed to;

make a second judgment as to whether the target driving power is smaller than or equal to a second driving power corresponding to an operating region wherein the driving source is driven under maximum load calculated based on a current output rotating speed;

when the second judgment shows that the target driving power is larger than the second driving power, the brake stops rotation of a connected rotating element.

8. A shift control device for a hybrid vehicle comprising:

a differential mechanism including at least four rotating elements whose rotating states are determined by rotating states of two of the at least four rotating elements, wherein elements connect a driving source, two motor/generators and an output; and

a controller programmed to;

calculate a target driving power based on a driving condition;

calculate a second driving source speed and a second driving source torque under optimum fuel efficiency wherein the target driving power is realized;

calculate a first motor/generator torque and a second motor/generator torque based on the second driving source speed and torque, the current output speed and the target driving power;

make a third judgment as to whether both the first motor/generator torque is larger than a first motor/generator maximum torque and the second motor/generator torque is larger than a second motor/generator maximum torque;

when the third judgment shows at least one of the first/second motor/generator torques is larger than the first/second motor/generator maximum torques, decrease the second driving source speed until both of the first/second motor/generator torques are equal to or smaller than the first/second motor/generator maximum torques.

9. A shift control device for a hybrid vehicle as claimed in claim 8, wherein the driving source is an engine.

10. A shift control device for a hybrid vehicle as claimed in claim 8, wherein the differential mechanism is a Ravigneawx planetary gear set.