Vehicle travel control device

• US 9,623,870 B2
• Filed: 10/31/2012
• Issued: 04/18/2017
• Est. Priority Date: 10/31/2012
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kuroki, Rentaro, Hirai, Takuya, Mitsuyasu, Masaki, Kim, Jonggap, Matsunaga, Masaki, Kido, Yasunari, Suzuki, Takeaki, Kogure, Takayuki, Okamura, Yukari, Sato, Akihiro, Kinoshita, Yusuke
• Primary Examiner(s): Melton, Todd
• Assistant Examiner(s): ROBERSON, JASON R
• Application Number:
  US14/439,384
• Publication Number:
  US 20150307103A1
• Time in Patent Office: 1,630 Days
• CPC Class Codes: B60T 13/00 Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions B60T8/00; valves incorporated in such systems B60T15/00
• CPC Class Codes: B60T 13/52 indirect, i.e. vacuum booster units
• CPC Class Codes: B60T 17/02 Arrangements of pumps or compressors, or control devices therefor
• CPC Class Codes: B60T 2201/022 Collision avoidance systems
• CPC Class Codes: B60T 7/042 by electrical means, e.g. using travel or force sensors
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2030/1809 Without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2710/182 Brake pressure, e.g. of fluid or between pad and disc
• CPC Class Codes: B60W 30/18072 Coasting
• CPC Class Codes: B60W 30/18109 Braking
• CPC Class Codes: B60W 30/182 Selecting between different operative modes, e.g. comfort and performance modes
• CPC Class Codes: B60Y 2300/18083 without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: F16D 48/02 Control by fluid pressure
• CPC Class Codes: F16H 61/21 Providing engine brake control
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect

Abstract

A running control device of a vehicle includes an engine and a brake booster amplifying a brake force by forming a negative pressure in a negative pressure tank by rotation of the engine. The running control device is configured to execute an engine brake running mode performed with the engine coupled to wheels such that an engine brake is applied by driven rotation of the engine and an inertia running mode performed with an engine brake force made lower than that of the engine brake running mode. The running control device executes a first inertia running mode performed with the rotation of the engine stopped and a second inertia running mode performed with the engine kept rotating as the inertia running mode in accordance with predefined respective execution conditions. The running control device comprises a prediction portion configured to predict a necessity of the negative pressure.

Claims

1. A running control device of a vehicle including an engine and a brake booster amplifying a brake force by forming a negative pressure in a negative pressure tank by rotation of the engine, the running control device comprising:

circuitry configured to;

execute an engine brake running mode performed with the engine coupled to wheels such that an engine brake is applied by driven rotation of the engine and an inertia running mode performed with an engine brake force made lower than that of the engine brake running mode,

execute a first inertia running mode performed with the rotation of the engine stopped and a second inertia running mode performed with the engine kept rotating as the inertia running mode in accordance with predefined respective execution conditions,

predict with a prediction portion a necessity of the negative pressure formed in the negative pressure tank by rotation of the engine, the necessity of the negative pressure being included in a condition for starting of each of the first inertia running mode and the second inertia running mode,

wherein the first inertia running mode is started on the condition that the necessity of the negative pressure is equal to or less than a predefined first determination value,

wherein the second inertia running mode is started when the necessity of the negative pressure is equal to or less than a predefined second determination value higher than the first determination value, and

wherein the engine brake running mode is executed when the necessity of the negative pressure is larger than the second determination value.

2. The running control device of a vehicle of claim 1, wherein

the prediction portion predicts the necessity of the negative pressure based on at least one of an inter-vehicle distance to a preceding vehicle, a road gradient, and a vehicle speed,

wherein when the necessity is predicted based on the inter-vehicle distance, the necessity of the negative pressure is higher when the inter-vehicle distance is shorter,

wherein when the necessity is predicted based on the road gradient, the necessity of the negative pressure is higher when the down-slope of the road surface is larger, and

wherein when the necessity is predicted based on the vehicle speed, the necessity of the negative pressure is higher when the vehicle speed is higher.

3. The running control device of a vehicle of claim 1, wherein

the second inertia running mode is started when the necessity of the negative pressure is in a region exceeding the first determination value and equal to or less than the second determination value.

4. The running control device of a vehicle of claim 1, wherein

the second inertia running mode is started when the necessity of the negative pressure is in a region equal to or less than the second determination value including a region equal to or less than the first determination value.

5. The running control device of a vehicle of claim 1, wherein

the first inertia running mode is a free-run inertia running mode in which the engine is separated from the wheels with fuel supply to the engine stopped to stop rotation of the engine, and wherein

the second inertia running mode is a neutral inertia running mode in which fuel is supplied to operate the engine while the engine is separated from the wheels.

6. The running control device of a vehicle of claim 1, wherein

the first inertia running mode is a free-run inertia running mode in which the engine is separated from the wheels with fuel supply to the engine stopped to stop rotation of the engine, and wherein

the second inertia running mode is a cylinder resting inertia running mode in which fuel supply to the engine is stopped with the engine coupled to the wheels while operation of a piston and intake/exhaust valves of at least one of multiple cylinders of the engine is stopped.

7. The running control device of a vehicle of claim wherein one of the first inertia running mode and the second inertia running mode is selected to start thereof in an overlapping region equal to or less than the first determination value.