Control method for a coordinated regenerative brake system

• US 20010024062A1
• Filed: 02/13/2001
• Published: 09/27/2001
• Est. Priority Date: 03/24/2000
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Sumitomo (SEI) Brake Systems, Inc. (Nippon Steel Corporation)
• Inventors: Yoshino, Masato
• Granted Patent: US 6,508,523 B2
• Time in Patent Office: Days
• US Class Current: 303/152
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2240/12 Speed
• 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: B60T 2270/602 ABS features related thereto
• CPC Class Codes: B60W 10/18 including control of braking 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 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/917 with transmission for changing gear ratio
• CPC Class Codes: Y10S 903/947 Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A coordinated regenerative brake system controls total brake torque to brake a vehicle in accordance with brake pedal operation and achieve deceleration intended by the driver'"'"'s operation of the brakes when the accelerator is not depressed. In a vehicle speed range below specific speed V1, engine brake equivalent torque Ta is set to decrease gradually to zero in accordance with vehicle speed V. When brake operation starts at a vehicle speed exceeding V1, the desired total brake torque Tq working on the vehicle is the sum of brake torque Tb corresponding to brake operation, and engine brake equivalent torque Ta, until vehicle speed reaches specific speed V1. When vehicle speed is V1 or less, brake torque is controlled using as desired total brake torque Tq the sum of brake torque Tb corresponding to brake operation, and first engine brake equivalent torque Ta1, if brake operation amount Sb is greater than or equal to a first brake operation amount Sb1.

Claims

1. A control method for a coordinated regenerative brake system in which a total brake torque to be applied to a vehicle is produced by coordinating friction brake torque and regenerative brake torque, wherein:

in the vehicle speed range less than or equal to a specific value (V1), when accelerator operator operation amount (Sa) is effectively zero, a brake torque (Ta) equivalent to engine brake torque working on the vehicle is set to be controlled to approach gradually zero in accordance with vehicle speed (V); and

when brake operator operation starts in a vehicle speed range exceeding the specific value (V1), brake torque is controlled

using as a desired total brake torque (Tq) for the vehicle in the vehicle speed range exceeding the specific value (V1), a sum of brake torque (Tb) corresponding to operational state of a brake operator, and brake torque (Ta) corresponding to operational state of accelerator operator, and;

in the vehicle speed range less than or equal to the specific value (V1),

using as the desired total brake torque (Tq) the sum of brake torque (Tb) corresponding to operational state of a brake operator, and first engine brake equivalent torque (Ta1), which is comparable to engine brake torque when vehicle speed (V) reaches the specific value (V1), when brake operator operation amount (Sb) is equal to or greater than a first brake operator operation amount (Sb1), which is brake operator operation when the vehicle speed (V) reaches the specific value (Vi), and;

using as the desired total brake torque (Tq), when brake operator operation amount (Sb) is less than the first brake operator operation amount (Sb1), the sum of brake torque (Tb) corresponding to operational state of a brake operator, and torque (Ta′

) calculated to approach brake torque (Ta), which corresponds to operational state of an accelerator operator, from first engine brake equivalent torque (Ta1) in accordance with the reduction ratio of brake operator operation amount (Sb).

2. A control method for a coordinated regenerative brake system according to

claim 1

, wherein when brake operator operation starts in a vehicle speed range less than or equal to the specific value (V1), brake torque is controlled

using as the desired total brake torque (Tq), while brake operator operation amount (Sb) is increasing, a sum of brake torque (Tb) corresponding to operational state of a brake operator, and second engine brake equivalent torque (Ta2), which is equivalent to engine brake torque at the start of brake operator operation;

and

using as the desired total brake torque (Tq), when brake operator operation amount (Sb) decreases, a sum of brake torque (Tb) corresponding to operational state of a brake operator, and torque (Ta″

), which is calculated to approach brake torque (Ta) corresponding to operational state of an accelerator operator from second engine brake equivalent torque (Ta2) in accordance with the reduction ratio of brake operator operation amount (Sb) from a relative maximum operation amount.