Braking apparatus for electric vehicle
First Claim
1. A braking apparatus for controlling the braking of an electric vehicle, comprisinga traveling electric motor for driving wheels of the electric vehicle,brake operating means associated with at least the driving wheels,accelerator operating means,mechanical anti-lock braking means for braking the associated wheels in accordance with operation of said brake operating means,means for determining a slip ratio between the associated wheels and a road surface and controlling said mechanical anti-lock braking means to maintain said slip ratio at a predetermined value, andelectric braking means operatively associated with said determining-and-controlling means and comprising first mode means for obtaining a first regeneration mode to produce braking torque by the electric motor, second mode means for obtaining a second regeneration mode to produce a smaller braking torque than in the first regeneration mode, third mode means for obtaining a coasting mode, and fourth mode means for obtaining a power propulsion mode absent regenerative braking torque produced by the electric motor, and logic selecting means operatively associated with the first mode means, the second mode means, the third mode means and the fourth mode means for selecting one of the first regeneration mode, the second regeneration mode, the coasting mode and the power propulsion mode, in response to data comprising wheel rotations, brake tread amount, slip and on-off regeneration and selectively regeneratively braking said traveling electric motor at least when the slip ratio is smaller than said predetermined value in accordance with the magnitude of a signal corresponding to the determined slip ratio, such that the mechanical anti-lock braking means and the electric braking means are operatively associated for approximating the predetermined range of the slip ratio under a variety of driving conditions to obtain braking while preventing skidding.
1 Assignment
0 Petitions
Accused Products
Abstract
A braking apparatus for an electric vehicle in which a mechanical anti-lock brake and regenerative braking cooperate with each other to improve a braking performance is realized. On condition that an accelerator is released off, the wheel rotation number is large, and a brake is trod on, a large regeneration mode is selected by a motor controller when a wheel slip is small, and a regeneration mode is selected when the wheel slip is large. When the wheel slip is small, the braking force exerted on each wheel is increased by the brake controller and the regenerative braking force is also increased so that a slip ratio comes quickly closer to 0.2. When the wheel slip is large, the brake controller reduces the braking force so that the slip ratio comes closer to 0.2. In this case, the regenerative braking force is smaller than the above case of the small wheel slip to such an extent that the operation of the brake controller is not disturbed. On condition that the accelerator is released off, the wheel rotation number is large, and the brake is released off, the regeneration mode is selected when the regeneration switch is turned on, and a coasting mode is selected when the regeneration switch is turned off.
-
Citations
7 Claims
-
1. A braking apparatus for controlling the braking of an electric vehicle, comprising
a traveling electric motor for driving wheels of the electric vehicle, brake operating means associated with at least the driving wheels, accelerator operating means, mechanical anti-lock braking means for braking the associated wheels in accordance with operation of said brake operating means, means for determining a slip ratio between the associated wheels and a road surface and controlling said mechanical anti-lock braking means to maintain said slip ratio at a predetermined value, and electric braking means operatively associated with said determining-and-controlling means and comprising first mode means for obtaining a first regeneration mode to produce braking torque by the electric motor, second mode means for obtaining a second regeneration mode to produce a smaller braking torque than in the first regeneration mode, third mode means for obtaining a coasting mode, and fourth mode means for obtaining a power propulsion mode absent regenerative braking torque produced by the electric motor, and logic selecting means operatively associated with the first mode means, the second mode means, the third mode means and the fourth mode means for selecting one of the first regeneration mode, the second regeneration mode, the coasting mode and the power propulsion mode, in response to data comprising wheel rotations, brake tread amount, slip and on-off regeneration and selectively regeneratively braking said traveling electric motor at least when the slip ratio is smaller than said predetermined value in accordance with the magnitude of a signal corresponding to the determined slip ratio, such that the mechanical anti-lock braking means and the electric braking means are operatively associated for approximating the predetermined range of the slip ratio under a variety of driving conditions to obtain braking while preventing skidding.
Specification