Control system for hybrid vehicle

• US 9,796,375 B2
• Filed: 03/04/2016
• Issued: 10/24/2017
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Oshiumi, Yasuhiro, Hirai, Makoto, Hokoi, Koji, Aoki, Takanori, Nakatsukasa, Hideo
• Primary Examiner(s): TRAN, KHOI H
• Assistant Examiner(s): Peche, Jorge
• Application Number:
  US15/061,046
• Publication Number:
  US 20160257297A1
• Time in Patent Office: 599 Days
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/14 Acceleration
• CPC Class Codes: B60L 2240/423 Torque
• 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: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/14 in conjunction with braking regeneration
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• 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 903/906 : Motor or generator
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A control system for a hybrid vehicle configured to reduce frequency of establishing an engine braking force is provided. The control system is configured to operate a first motor as a motor to increase torque of an output member while halting the output shaft of the engine by a brake, and to increase the deceleration torque of the second motor, if a state of charge of the battery is higher than a predetermined threshold level when deceleration of the hybrid vehicle is demanded.

Claims

1. A control system for a hybrid vehicle that is applied to a hybrid vehicle comprising:

a prime mover including an engine in which an output shaft is halted by a brake, a first motor, and a second motor that applies torque to an output member and that is electrically connected to the first motor through a battery; and

a power distribution device that performs a differential action among a first rotary element, a second rotary element, and a third rotary element;

in which the engine is connected to a first rotary element, the first motor is connected to a second rotary element, and the output member is connected to a third rotary element;

wherein the control system is configured to operate the second motor as a generator to regenerate energy to establish a deceleration torque while charging the battery with an electric power generated by the second motor when deceleration of the hybrid vehicle is demanded;

wherein the control system comprises a controller that controls the first motor and the second motor; and

wherein the controller is configured to operate the first motor as a motor to increase torque of the output member while halting the output shaft of the engine by the brake, and to increase the deceleration torque of the second motor, if a state of charge of the battery is higher than a predetermined threshold level when deceleration of the hybrid vehicle is demanded.

2. The control system for a hybrid vehicle as claimed in claim 1, wherein the controller is further configured:

to calculate a required drive torque; and

to control an output torque of the first motor and the deceleration torque of the second motor to achieve the calculated required drive torque.

3. The control system for a hybrid vehicle as claimed in claim 1, wherein the controller is further configured to control the first motor and the second motor to increase the deceleration torque of the second motor in an amount of the torque of the first motor to increase the rotational speed thereof.

4. The control system for a hybrid vehicle as claimed in claim 1, wherein the controller is further configured to establish the deceleration torque by the second motor without operating the first motor as a motor if the state of charge of the battery is lower than the predetermined threshold level when a deceleration of the vehicle is demanded.

5. The control system for a hybrid vehicle as claimed in claim 1, wherein the threshold level is set to be lower than an upper limit level of the state of charge of the battery.