ELECTRIC VEHICLE REGENERATIVE BRAKING SYSTEM
A method and system for braking a vehicle are disclosed. The vehicle has at least one of an electronic stability control system and an antilock brake system. The vehicle may also include a regenerative brake adapted to apply a regenerative braking torque to slow the vehicle. The vehicle may further include a pressure sensor adapted to sense pressure in a hydraulic brake line. The pressure sensor may be a component of the at least one of the electronic stability control system and the antilock brake system. The vehicle may also include a controller adapted to control the regenerative braking torque of the regenerative brake based on at least the sensed pressure.
1 . A braking system for a vehicle, the vehicle having at least one of an electronic stability control system and an antilock brake system, the braking system comprising:
a regenerative braking system adapted to apply a regenerative braking torque to the vehicle to slow the vehicle;
a pressure sensor adapted to sense pressure in a hydraulic brake line, wherein the pressure sensor is a component of the at least one of the electronic stability control system and the antilock brake system; and
a controller adapted to control the regenerative braking torque of the regenerative braking system based at least in part on the sensed pressure.
2 . The braking system of claim 1 , wherein the controller is adapted to increase the regenerative braking torque in response to an increase in the sensed pressure.
3 . The braking system of claim 2 , wherein the controller is adapted to increase the regenerative braking torque linearly in response to the increase in the sensed pressure.
4 . The braking system of claim 1 , wherein the regenerative braking torque is a maximum regenerative braking torque when the sensed pressure is greater than an upper threshold pressure.
5 . The braking system of claim 1 , wherein the controller is adapted to disable the regenerative braking for an accelerator input greater than a threshold accelerator input.
6 . The braking system of claim 1 , wherein the controller is adapted to increase the regenerative braking torque as an accelerator input decreases from a threshold accelerator input.
7 . The braking system of claim 1 , wherein the controller is adapted to maintain the regenerative braking torque at a constant positive torque when no accelerator or braking inputs are sensed.
8 . The braking system of claim 1 , wherein the controller is adapted to increase the regenerative braking torque when the vehicle travels above a threshold vehicle speed input.
9 . The braking system of claim 1 , wherein the controller is adapted to increase the regenerative braking torque in response to an actuation of a brake switch.
10 . The braking system of claim 1 , wherein the controller is adapted to increase the regenerative braking torque in response to increasing rates of pressure increase.
11 . The braking system of claim 1 , wherein the controller is adapted to decrease the regenerative braking torque in response to wheel slippage.
12 . The braking system of claim 1 , wherein the controller is adapted to provide a trouble code in response to sensed excessive brake pedal travel.
13 . The braking system of claim 1 , wherein the controller is adapted to adjust a profile of the regenerative braking torque in response to a change in vehicle speed input to the controller.
14 . The braking system of claim 1 further comprising a drive mode selector that permits the controller to adjust a profile of the regenerative braking torque in response to an input provided by the drive mode selector.
15 . A method for braking a vehicle having at least one of an electronic stability control system and antilock brake system, the method comprising:
receiving hydraulic pressure information from a pressure sensor of the at least one of the electronic stability control system and antilock brake system of the vehicle; and
applying a regenerative braking torque to slow the vehicle in response to the hydraulic pressure information.
16 . The method of claim 16 further comprising increasing the regenerative braking torque in response to increasing hydraulic pressure.
17 . The method of claim 17 , wherein increasing the regenerative braking torque further comprises linearly increasing the regenerative braking torque with increasing hydraulic pressure.
18 . The method of claim 16 further comprising applying a maximum regenerative braking torque when the hydraulic pressure is greater than an upper threshold pressure.
19 . The method of claim 19 , wherein the upper threshold pressure is approximately 25 bar.
20 . The braking system of claim 16 further comprising disabling the regenerative braking for an accelerator input greater than a threshold accelerator input.
21 . The braking system of claim 16 further comprising increasing the regenerative braking torque as an accelerator input decreases from a threshold accelerator input.
22 . The braking system of claim 16 further comprising maintaining the regenerative braking torque at a constant positive torque when no accelerator or braking inputs are sensed.
23 . The braking system of claim 16 further comprising increasing the regenerative braking torque in response to an actuation of a brake switch.
24 . The method of claim 16 further comprising increasing the regenerative braking torque in response to increasing rates of hydraulic pressure rise.
25 . The braking system of claim 16 further comprising decreasing the regenerative braking torque in response to wheel slippage.
26 . The braking system of claim 16 further comprising providing a trouble code in response to excessive brake pedal travel.
27 . The method of claim 16 further comprising sensing a speed of the vehicle and adjusting the regenerative braking torque in response to the speed of the vehicle.
28 . The method of claim 16 further comprising sensing an ambient temperature and adjusting the regenerative braking torque in response to the ambient temperature.
29 . The method of claim 16 further comprising selecting a driving mode and adjusting a profile of the regenerative braking torque in response to the selected drive mode.
30 . A method for braking a vehicle comprising:
disabling regenerative braking for an accelerator input above a threshold accelerator input;
increasing regenerative braking for a decreasing accelerator input when the accelerator input is below the threshold accelerator input;
increasing regenerative braking when a brake switch actuates; and
increasing regenerative braking relative to increasing braking pressure.
31 . The method of claim 31 further comprising maintaining a constant amount of regenerative braking for a braking pressure above a threshold braking pressure.
32 . The method of claim 31 wherein the step of increasing regenerative braking relative to a decreasing accelerator input further comprises linearly increasing regenerative braking.