Running control system for vehicle

• US 9,604,644 B2
• Filed: 08/08/2012
• Issued: 03/28/2017
• Est. Priority Date: 08/08/2012
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kim, Jonggap
• Primary Examiner(s): Hansen, Colby M
• Application Number:
  US14/414,593
• Publication Number:
  US 20150191172A1
• Time in Patent Office: 1,693 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 10/18 including control of braking systems
• 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 30/18072 Coasting
• CPC Class Codes: B60W 30/18136 Engine braking
• CPC Class Codes: F16D 48/02 Control by fluid pressure
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect

Abstract

A running control system for vehicles is provided to reduce uncomfortable feeling during coasting by adjusting a braking force. The running control system is applied to a vehicle having a braking device adapted to generate a braking force according to an operation of a driver irrespective of an engagement state of the engagement elements disposed between a prime mover and drive wheels. The running control system comprises a controller that applies a braking force of the prime mover to the drive wheels by bringing the engagement elements into engagement to enable torque transmission between the prime mover and the drive wheels, when the braking force of the braking device is eliminated by aborting an operation of the braking device during coasting while disengaging the engagement elements to interrupt torque transmission between the prime mover and the drive wheels.

Claims

1. A running control system for a vehicle having an engagement element that is disposed between a prime mover and drive wheels to allow and interrupt power transmission therebetween, and a braking device that generates a braking force according to an operation of a driver irrespective of an engagement state of the engagement element, comprising:

a controller that controls a running condition of the vehicle;

wherein the controller is configured to;

determine an execution and a termination of an operation of the braking device during coasting of the vehicle while controlling the engagement element to disengage,

control the running condition of the vehicle to maintain the coasting of the vehicle without controlling the engagement element to engage when the execution of the operation of the braking device is determined, and

control the engagement element to engage when the termination of the operation of the braking device is determined to apply a braking force of the prime mover to the drive wheels.

2. The running control system as claimed in claim 1, wherein the controller is further configured to:

determine a deceleration demand of the driver based on the operation of the braking device,

control the engagement element to engage to apply the braking force of the prime mover to the drive wheels to allow torque transmission between the prime mover and the drive wheels, when the deceleration demand of the driver exceeds a predetermined demand, and

control the running condition of the vehicle to maintain the coasting of the vehicle when the deceleration demand of the driver is smaller than the predetermined demand.

3. The running control system as claimed in claim 2,

wherein the braking device includes a brake pedal, and

wherein the controller is further configured to calculate the deceleration demand of the driver based on a depressing force applied to the brake pedal.

4. The running control system as claimed in claim 2,

wherein the engagement element includes at least a first engagement element and a second engagement element;

and

wherein the vehicle includes a transmission that is disposed on a powertrain to transmit power from the prime mover to the drive wheels, and that establishes a gear stage by engaging the first engagement element and the second engagement element to allow power transmission between the prime mover and the drive wheels.

5. The running control system as claimed in claim 4,

wherein the braking device includes a brake pedal, and

wherein the controller is further configured to calculate the deceleration demand of the driver based on a depressing force applied to the brake pedal.

6. The running control system as claimed in claim 4,

wherein the coasting includes a running condition achieved by disengaging any one of the first and the second engagement elements;

and

wherein the controller is further configured to control any one of the first and the second engagement elements that is in disengagement to engage to apply the braking force of the prime mover to the drive wheels.

7. The running control system as claimed in claim 1,

wherein the engagement element includes at least a first engagement element and a second engagement element;

and

wherein the vehicle includes a transmission that is disposed on a powertrain to transmit power from the prime mover to the drive wheels, and that establishes a gear stage by engaging the first engagement element and the second engagement element to allow power transmission between the prime mover and the drive wheels.

8. The running control system as claimed in claim 7,

wherein the coasting includes a running condition achieved by disengaging any one of the first and the second engagement elements;

and

wherein the controller is further configured to control any one of the first and the second engagement elements that is in disengagement to engage to apply the braking force of the prime mover to the drive wheels.