Patent ID: 6508523
Filing Date: 2003-01-21
Classification: B60K,B60L,B60T,B60W,Y02T,Y10S

Abstract:
A method of controlling a coordinated regenerative brake system of a vehicle by coordinating a friction brake torque and a regenerative brake torque for a desired brake torque (Tq), the friction brake torque comprising a brake operation brake torque (Tb) responsive to a brake operation amount (Sb), and the regenerative brake torque comprising an accelerator operation brake torque (Ta) responsive to an accelerator operation amount (Sa), the method comprising:when a speed of the vehicle (V) is less than or equal to a first predetermined vehicle speed (V1), and when the accelerator operation amount (Sa) is effectively zero and no brake operation amount (Sb) is made, controlling the desired brake torque (Tq) using the accelerator operation brake torque (Ta) to gradually approach zero in accordance with the vehicle speed (V), the accelerator operation brake torque (Ta) being equivalent to an engine brake torque working on the vehicle; and when the vehicle speed (V) is greater than the first predetermined vehicle speed (V1) when a brake operation begins, controlling the desired brake torque (Tq): using a sum of the brake operation brake torque (Tb) and the accelerator operation brake torque (Ta) when the vehicle speed exceeds the predetermined vehicle speed (V1); using a sum of the brake operation brake torque (Tb) and a first accelerator operation brake torque (Ta1), which is equivalent to the engine brake torque at the first predetermined vehicle speed (V1), when the vehicle speed (V) is less than or equal to the first predetermined vehicle speed (V1) and a brake operation amount (Sb) is greater than or equal to a first brake operation brake amount (Sb1), which corresponds to the first predetermined vehicle speed (V1); and using a sum of the brake operation brake torque (Tb) and a calculated accelerator operation brake torque (Taâ€²), the calculated accelerator operation brake torque (Taâ€²) being calculated to approach the accelerator operation brake torque (Ta) from the first accelerator operation brake torque (Ta1) in accordance with a reduction ratio of the brake operation amount (Sb), when the vehicle speed (V) is less than or equal to the first predetermined vehicle speed (V1) and the brake operation brake amount (Sb) is less than the first brake operation brake amount (Sb1).