Method and apparatus for controlling hybrid electric vehicle

Patent metadata

Field	Value
Publication number	US-2017096134-A1
Application number	US-201514961229-A
Country	US
Kind code	A1
Filing date	Dec 7, 2015
Priority date	Oct 6, 2015
Publication date	Apr 6, 2017
Grant date	—

Abstract

A method and an apparatus for controlling a hybrid electric vehicle are provided. The apparatus includes a navigation device that provides information regarding a gradient, a speed limit, and a traffic speed of a road. An accelerator pedal position detector detects a position of an accelerator pedal and a brake pedal position detector detects a position of a brake pedal. A vehicle speed detector detects a vehicle speed, a state of charge (SOC) detector detects an SOC of a battery, and a gear stage detector detects a gear stage that is currently engaged. A controller operates the hybrid vehicle based on signals of the navigation device, the accelerator pedal position detector, the brake pedal position detector, the vehicle speed detector, the SOC detector, and the gear stage detector.

First claim

What is claimed is:

1 . A method of controlling a hybrid electric vehicle, comprising:
setting, by a controller, a route from a current position of the hybrid electric vehicle toward a destination; setting, by the controller, a plurality of sections based on information regarding an altitude of the route; calculating, by the controller, an expected driving force for each section based on a distance for each section, an average effective gradient for each section, and an average effective vehicle speed for each section; determining, by the controller, an expected gear stage for each section based on the average effective gradient for each section and the average effective vehicle speed for each section; calculating, by the controller, an expected demand torque of a driver for each section based on the expected driving force for each section and the expected gear stage for each section; calculating, by the controller, an expected input speed of a transmission for each section based on the average effective vehicle speed for each section and the expected gear stage for each section; calculating, by the controller, a demand torque of an engine for each section and a demand torque of a motor for each section from the expected demand torque of the driver for each section with reference to an optimal operating point of the engine; calculating, by the controller, demand power of the motor for each section based on the demand torque of the motor for each section calculated with reference to the optimal operating point of the engine and the expected input speed of the transmission for each section; calculating, by the controller, a state of charge (SOC) gain for each section based on the demand power of the motor for each section calculated with reference to the optimal operating point of the engine; calculating, by the controller, a first virtual SOC trend line for each section based on the SOC gain for each section calculated with reference to the optimal operating point of the engine; calculating, by the controller, an available torque of the motor for each section based on the first virtual SOC trend line and the expected input speed of the transmission for each section; calculating, by the controller, a limit of the available torque of the motor for each section based on the expected demand torque of the driver for each section and the available torque of the motor for each section; calculating, by the controller, an available SOC for each section based on the limit of the available torque of the motor for each section; setting, by the controller, an objective function for minimizing accumulated work of the engine in the plurality of sections; setting, by the controller, constraint functions of a second virtual SOC trend line to minimize the accumulated work of the engine in the plurality of sections, an expected demand torque of the motor for each section, an expected demand torque of the engine, and accumulated driving work in the plurality of sections; determining, by the controller, design variables that satisfy the objective function and the constraint functions, wherein the design variables include the second virtual SOC trend line, the expected demand torque of the motor for each section, and the accumulated work of the motor in the plurality of sections; calculating, by the controller, the expected demand torque of the engine for each section based on the expected demand torque of the driver for each section and the expected demand torque of the motor for each section; determining, by the controller, an expected driving mode of the hybrid electric vehicle for each section based on the expected demand torque of the driver for each section, the expected demand torque of the engine for each section, and the expected demand torque of the motor for each section; determining, by the controller, a first threshold line and a second threshold line based on the second virtual SOC trend line, the average effective gradient for each section, and the average effective vehicle speed for each section; and operating, by the controller, the engine and the motor using the expected driving mode of the hybrid electric vehicle, the first threshold line, and the second threshold line.

2 . The method of claim 1 , wherein the operating of the engine and the motor using the expected driving mode of the hybrid electric vehicle, the first threshold line, and the second threshold line includes:
determining, by the controller, whether a current SOC of a battery is between the first threshold line and the second threshold line; when the current SOC of the battery is between the first threshold line and the second threshold line, calculating, by the controller, a demand torque of the motor at a current time based on a difference between an actual demand torque of the driver at the current time and the expected demand torque of the driver in a current section and the expected demand torque of the motor in the current section; calculating, by the controller, a demand torque of the engine at the current time based on the actual demand torque of the driver at the current time and a demand torque of the motor at the current time; and operating, by the controller, the engine and the motor based on the demand torque of the engine at the current time and the demand torque of the motor at the current time.

3 . The method of claim 2 , wherein the operating of the engine and the motor using the expected driving mode of the hybrid electric vehicle, the first threshold line, and the second threshold line includes:
when the current SOC of the battery is less than the first threshold line, calculating, by the controller, a first delta SOC which is a difference between the current SOC of the battery and the first threshold line; calculating, by the controller, a first correction value based on the first delta SOC; and performing, by the controller, a charging-oriented control to charge the battery using the first correction value.

4 . The method of claim 3 , wherein the performing of the charging-oriented control for charging the battery by using the first correction value includes:
calculating, by the controller, a corrected demand torque of the motor at the current time based on the demand torque of the motor at the current time and the first corrections value; calculating, by the controller, a corrected demand torque of the engine at the current time based on the actual demand torque of the driver at the current time and the corrected demand torque of the motor at the current time; and operating, by the controller, the engine and the motor based on the corrected demand torque of the engine at the current time and the corrected demand torque of the motor at the current time.

5 . The method of claim 2 , wherein the operating of the engine and the motor using the expected driving mode of the hybrid electric vehicle, the first threshold value and the second threshold value includes:
when the current SOC is greater than the second threshold line, calculating, by the controller, a second delta SOC which is difference between the current SOC of the battery and the second threshold line; calculating, by the controller, a second correction value based on the second delta SOC; and performing, by the controller, discharging-oriented control to discharge the battery using the second correction value.

6 . The method of claim 5 , wherein the performing of the discharging-oriented control to discharge the battery by using the second correction value includes:
calculating, by the controller, a corrected demand torque of the motor at the current time based on the demand torque of the motor at the current time and the second correction value; calculating, by the controller, a corrected demand torque of th

Assignees

• Kia Motors Corp
• Hyundai Motor Co Ltd

Inventors

• Yoon Dong Pil
• Lee Jeamun
• Choi Kwang Hun
• Kim Tae Soo
• Jo Kyu Hwan
• Kim Jungwook

Classifications

• B60K2006/4825

  Electric machine connected or connectable to gearbox input shaft · CPC title

• B60W2552/20

  Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments · CPC title

• B60W2552/25

  Road altitude · CPC title

• B60W2540/12

  Brake pedal position · CPC title

• B60W2710/0666

  Engine torque · CPC title