Drive control system for hybrid vehicles

• US 6,315,068 B1
• Filed: 02/19/1999
• Issued: 11/13/2001
• Est. Priority Date: 03/06/1998
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Oba, Hidehiro, Hoshiya, Kazumi
• Primary Examiner(s): Mai, Lanna
• Assistant Examiner(s): To, Toan C
• Application Number:
  US09/253,521
• Time in Patent Office: 998 Days
• Field of Search: 180/65.2, 180/65.8, 180/65.6, 701/22, 477/20
• US Class Current: 180/65.25
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 10/26 for electrical energy, e.g. batteries or capacitors
• 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 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/91 Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/946 Characterized by control of driveline clutch

Abstract

A drive control system for a hybrid vehicle, in which the output torques of an electric motor and an internal combustion engine are synthesized by and outputted from a torque synthesizing/distributing mechanism. The target speed of the engine is determined on the basis of the output demand for the engine and the output speed of the torque synthesizing/distributing mechanism, and the target speed of the motor is determined on the basis of the target speed of the engine and the output speed of the torque synthesizing/distributing mechanism. The output of the engine is controlled to the output torque which is determined on the basis of the output demand for the engine and the target speed of the engine, and the output speed of the motor is controlled to the target speed.

Claims

1. A drive control system for a hybrid vehicle, which has a torque synthesizing/distributing mechanism for synthesizing an output torque of an electric motor and an output torque of an internal combustion engine and for outputting a synthesized torque therefrom, comprising:

target engine speed detecting means for determining a target speed of the engine on the basis of an output demand for the engine and an output speed of said torque synthesizing/distributing mechanism;

target motor speed detecting means for determining a target speed of the motor on the basis of the target speed of the engine and the output speed of said torque synthesizing/distributing mechanism;

engine output control means for controlling the output of the engine to the output torque which is determined on the basis of the output demand for the engine and the target speed of the engine; and

motor speed control means for controlling an output speed of the motor to the target motor speed which is determined by said target motor speed detecting means.

2. A hybrid vehicle drive control system according to claim 1, further comprising:

speed control means for setting the target speed of the engine so as to eliminate a difference among the speed of the engine, the speed of the motor and the output speed of said torque synthesizing/distributing mechanism as a vehicle speed increases.

3. A hybrid vehicle drive control system according to claim 1,

wherein said torque synthesizing/distributing mechanism includes a gear mechanism having three rotary elements for performing a differential action.

4. A hybrid vehicle drive control system according to claim 3,

wherein a first one of said three rotary elements is selectively connected to the engine through clutch means whereas a second rotary element is connected to the motor.

5. A hybrid vehicle drive control system according to claim 4, further comprising:

an integral clutch for connecting any two of said rotary elements selectively.

6. A hybrid vehicle drive control system according to claim 5, further comprising:

speed difference detecting means for detecting a difference between the output speed of the engine and the output speed of the motor; and

application command means for applying said integral clutch when the difference, as detected by said speed difference detecting means, between the output speed of the engine and the output speed of the motor is less than a predetermined value.

7. A hybrid vehicle drive control system according to claim 6,

wherein said integral clutch includes a clutch to be applied by an oil pressure, and

wherein said application command means includes means for setting the oil pressure at the beginning of application of said integral clutch to a level higher than a level later applied for steady state operation of said integral clutch.

8. A hybrid vehicle drive control system according to claim 6, further comprising:

torque lowering means for lowering the output torque of the motor gradually after said integral clutch was completely applied.

9. A drive control system for a hybrid vehicle having a torque synthesizing/distributing mechanism for synthesizing an output torque of an electric motor and an output torque of an internal combustion engine and for outputting a synthesized torque therefrom comprising:

target engine speed detecting means for determining a target speed of the engine on the basis of an output demand for the engine and an output speed of said torque synthesizing/distributing mechanism;

target motor speed detecting means for determining a target speed of the motor on the basis of the target speed of the engine and the output speed of said torque synthesizing/distributing mechanism;

engine output control means for controlling the output of the engine to the output torque which is determined on the basis of the output demand for the engine and the target speed of the engine; and

motor torque control means for controlling the output torque of the motor so that the speed of the motor may be said target motor speed.