Systems and methods for smooth stopping of a vehicle

Patent metadata

Field	Value
Publication number	US-2017282925-A1
Application number	US-201615085152-A
Country	US
Kind code	A1
Filing date	Mar 30, 2016
Priority date	Mar 30, 2016
Publication date	Oct 5, 2017
Grant date	—

Abstract

A system includes a sensor designed to detect data corresponding to a speed of a vehicle and a motor designed to convert electrical energy into driving torque. The system also includes a first wheel coupled to the motor and designed to propel the vehicle in response to receiving the driving torque along with a second wheel. The system also includes a brake coupled to at least one of the first wheel or the second wheel and designed to apply a braking torque to the at least one of the first wheel or the second wheel. The system also includes an ECU coupled to the sensor and the motor and designed to control the motor to begin controlled braking by applying the driving torque to the first wheel to at least partially offset the braking torque when the speed of the vehicle is at or below a braking threshold speed.

First claim

What is claimed is:

1 . A system for reducing oscillations when a vehicle is braking, the system comprising:
a sensor configured to detect data corresponding to a speed of the vehicle; a motor configured to convert electrical energy into driving torque; a first wheel coupled to the motor and configured to propel the vehicle in response to receiving the driving torque; a second wheel; a brake coupled to at least one of the first wheel or the second wheel and configured to apply a braking torque to the at least one of the first wheel or the second wheel to reduce the speed of the vehicle; and an electronic control unit (ECU) coupled to the sensor and the motor and configured to control the motor to begin controlled braking by applying the driving torque to the first wheel to at least partially offset the braking torque when the speed of the vehicle is at or below a braking threshold speed.

2 . The system of claim 1 wherein the ECU is further configured to control the motor to apply the driving torque to the first wheel until the speed of the vehicle is zero miles per hour (0 mph).

3 . The system of claim 1 wherein the braking threshold speed corresponds to a vehicle speed below which it is deemed safe for the braking torque to be offset and corresponds to a value between 0.5 miles per hour (0.5 mph) and 3 mph.

4 . The system of claim 1 further comprising:
a brake pedal coupled to the ECU and configured to transmit a signal to the ECU indicating that a braking operation is being requested in response to being depressed; and
an accelerator pedal coupled to the ECU and configured to transmit a signal to the ECU indicating that an acceleration operation is being requested in response to being depressed,
wherein the ECU is further configured to control the motor to stop controlled braking when at least one of the brake pedal is undepressed or the accelerator pedal is depressed.

5 . The system of claim 1 further comprising at least one of a traction sensor configured to detect a current amount of traction of the at least one of the first wheel or the second wheel or a traction input device configured to receive data corresponding to the current amount of traction of the at least one of the first wheel or the second wheel and wherein the ECU is further configured to prevent the controlled braking when the current amount of traction of the at least one of the first wheel or the second wheel is below a traction threshold.

6 . The system of claim 1 further comprising at least one of a brake pedal coupled to the ECU and configured to transmit a signal to the ECU indicating a desired amount of braking in response to being depressed or a mass sensor coupled to the ECU and configured to detect mass vehicle data corresponding to a mass of the vehicle and wherein the ECU is further configured to determine whether to begin controlled braking based on at least one of a rate of deceleration of the vehicle, the desired amount of braking or the mass of the vehicle.

7 . The system of claim 6 wherein the ECU is further configured to determine how much driving torque to be applied by the motor based on at least one of the rate of deceleration of the vehicle, the desired amount of braking or the mass of the vehicle.

8 . A system for reducing oscillations when a vehicle is braking, the system comprising:
a sensor configured to detect data corresponding to a speed of the vehicle; a first wheel configured to propel the vehicle in response to receiving driving torque; a second wheel; a brake coupled to at least one of the first wheel or the second wheel and configured to apply a braking torque to the at least one of the first wheel or the second wheel to reduce the speed of the vehicle; and an electronic control unit (ECU) coupled to the sensor and the brake and configured to control the brake to begin controlled braking by reducing the braking torque applied to the at least one of the first wheel or the second wheel when the speed of the vehicle is at or below a braking threshold speed.

9 . The system of claim 8 wherein the ECU is further configured to control the brake to reduce the braking torque applied to the at least one of the first wheel or the second wheel until the speed of the vehicle is zero miles per hour (0 mph).

10 . The system of claim 8 wherein the braking threshold speed corresponds to a vehicle speed below which it is deemed safe for the braking torque to be reduced and corresponds to a value between 0.5 miles per hour (0.5 mph) and 3 mph.

11 . The system of claim 8 further comprising:
a brake pedal coupled to the ECU and configured to transmit a signal to the ECU indicating that a braking operation is being requested in response to being depressed; and
an accelerator pedal coupled to the ECU and configured to transmit a signal to the ECU indicating that an acceleration operation is being requested in response to being depressed,
wherein the ECU is further configured to control the brake to stop controlled braking when at least one of the brake pedal is undepressed or the accelerator pedal is depressed.

12 . The system of claim 8 further comprising at least one of a traction sensor configured to detect a current amount of traction of the at least one of the first wheel or the second wheel or a traction input device configured to receive data corresponding to the current amount of traction of the at least one of the first wheel or the second wheel and wherein the ECU is further configured to prevent the controlled braking when the current amount of traction of the at least one of the first wheel or the second wheel is below a traction threshold.

13 . The system of claim 8 further comprising at least one of a brake pedal coupled to the ECU and configured to transmit a signal to the ECU indicating a desired amount of braking in response to being depressed or a mass sensor coupled to the ECU and configured to detect mass vehicle data corresponding to a mass of the vehicle and wherein the ECU is further configured to determine whether to begin controlled braking based on at least one of a rate of deceleration of the vehicle, the desired amount of braking or the mass of the vehicle.

14 . The system of claim 13 wherein the ECU is further configured to determine how much for the brake to reduce the braking torque based on at least one of the rate of deceleration of the vehicle, the desired amount of braking or the mass of the vehicle.

15 . A method for reducing oscillations when a vehicle is braking comprising:
detecting, by a sensor, data corresponding to a speed of the vehicle; determining, by an electronic control unit (ECU), that controlled braking should begin when the speed of the vehicle is at or below a braking threshold speed; and controlling, by the ECU, a vehicle component to reduce or offset an amount of braking torque of the vehicle when controlled braking should begin.

16 . The method of claim 15 wherein controlling the vehicle component to reduce or offset the amount of braking torque of the vehicle includes controlling, by the ECU, a motor of the vehicle to increase driving torque of the vehicle to offset the amount of braking torque of the vehicle.

17 . The method of claim 15 wherein controlling the vehicle component to reduce or offset the amount of braking torque of the vehicle includes controlling, by the ECU, a brake of the vehicle to decrease the amount of braking torque of the vehicle.

18 . The method of claim 15 wherein controlling the vehicle component to reduce or offset the amount of b

Assignees

• Toyota Motor Eng & Mfg North America Inc

Inventors

• Geller Benjamin M

Classifications

• B60W2552/15

  Road slope, i.e. the inclination of a road segment in the longitudinal direction · CPC title

• B60W30/181

  Preparing for stopping · CPC title

• B60W2540/12

  Brake pedal position · CPC title

• B60W2710/18

  Braking system · CPC title

• B60W2520/10

  Longitudinal speed · CPC title