Regenerative braking control device of electric vehicle

A regenerative braking control device of an electric vehicle, wherein the electric vehicle includes an electric motor coupled to a drive wheel, the regenerative braking control device comprising:

• an electric motor controller that controls powering or regeneration of the electric motor;
• and
• a regeneration amount setting unit that sets a regeneration amount by a driver operation and that can change the regeneration amount according to an intention of a driver;
• and
• a gradient estimating unit that estimates road surface gradient of the vehicle,
• wherein the electric motor controller includes a regeneration instruction torque limitation unit that limits the regeneration amount so as to decrease when a vehicle speed is reduced, and
• wherein the regeneration instruction torque limitation unit limits the regeneration amount at a higher vehicle speed on an uphill gradient than on a downhill gradient.

A regenerative braking control device of an electric vehicle, wherein the electric vehicle includes an electric motor coupled to a drive wheel, the regenerative braking control device comprising:

• an electric motor controller that controls powering or regeneration of the electric motor;
• and
• a regeneration amount setting unit that sets a regeneration amount by a driver operation and that can change the regeneration amount according to an intention of a driver,
• wherein the electric motor controller includes a regeneration instruction torque limitation unit that limits, immediately before stop of the vehicle with a motor rotation speed in a low-speed area, the regeneration amount so as to decrease when the motor rotation speed is reduced,
• wherein the regeneration instruction torque limitation unit includes a gradient correction torque calculation portion that calculates a gradient correction torque according to a plurality of limit maps which are set with reference to a flat road and a road surface gradient,
• wherein a torque value obtained based on any map selected from the limit maps by operations of the driver and the motor rotation speed is set as a limit map lower limit value,
• wherein a regeneration torque lower limit value is calculated by correcting the limit map lower limit value by using the gradient correction torque such that a process of the regeneration instruction torque limitation unit is performed to correspond to variations in the road surface gradient, and
• wherein when torque limitation processing is started, even if an instruction to change the regeneration amount is provided by the driver, the regeneration instruction torque limitation unit performs regeneration instruction torque limitation processing without receiving the instruction.