Vehicle control system

• US 9,540,004 B2
• Filed: 06/20/2012
• Issued: 01/10/2017
• Est. Priority Date: 06/20/2012
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kim, Jonggap, Kato, Yasuyuki
• Primary Examiner(s): Jos, Basil T
• Application Number:
  US14/406,748
• Publication Number:
  US 20150149058A1
• Time in Patent Office: 1,665 Days
• US Class Current: 1/1
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• 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 2510/0638 Engine speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/021 Clutch engagement state
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 30/18072 Coasting
• CPC Class Codes: F16D 2500/10412 Transmission line of a vehicle
• CPC Class Codes: F16D 2500/3108 Vehicle speed
• CPC Class Codes: F16D 2500/3127 Road slope
• CPC Class Codes: F16D 2500/3128 Distance from the vehicle to an external element, e.g. to an obstacle, to an other vehicle or a target
• CPC Class Codes: F16D 2500/31433 Brake pedal position threshold, e.g. switch
• CPC Class Codes: F16D 2500/31453 Accelerator pedal position threshold, e.g. switch
• CPC Class Codes: F16D 2500/5043 Engine fuel consumption
• CPC Class Codes: F16D 2500/50825 Hill climbing or descending
• CPC Class Codes: F16D 2500/5085 Coasting
• CPC Class Codes: F16D 48/06 Control by electric or electronic means, e.g. of fluid pressure
• CPC Class Codes: Y02T 10/60 : Other road transportation technologies with climate change mitigation effect

Abstract

A vehicle control system is provided. The vehicle control system is applied to a vehicle having a clutch device adapted to selectively connect and disconnect a power transmission route between a prime mover and drive wheels. The vehicle control system disconnects the power transmission route during running to allow the vehicle to coast. The vehicle control system is comprised of: a means detecting a vehicle speed; a means detecting an operation of an accelerator by a driver; a means detecting a braking operation of the driver; an execution means executing a coasting control when an operating amount of the accelerator is reduced to be smaller than a predetermined value during running, by bringing the clutch device into disengagement to disconnect the power transmission route so as to allow the vehicle to coast; a determination means determining whether or not a deceleration demand of the driver is larger than a predetermined value during execution of the coasting control based on the vehicle speed and the braking operation; and a termination means determining a fact that the deceleration demand is strong if the deceleration demand is larger than the predetermined value, and that terminates the coasting control by bringing the clutch device into engagement to connect the power transmission route.

Claims

1. A vehicle control system, that is applied to a vehicle having a clutch device adapted to selectively connect and disconnect a power transmission route between a prime mover and drive wheels, and that is configured to disconnect the power transmission route during running to allow the vehicle to coast, comprising a controller that is configured to:

detect a vehicle speed;

detect an operation of an accelerator by a driver;

detect a braking operation of the driver;

execute a coasting control when an operating amount of the accelerator is reduced to be smaller than a predetermined value during running, by bringing the clutch device into disengagement to disconnect the power transmission route so as to allow the vehicle to coast;

determine whether or not a deceleration demand of the driver is larger than a predetermined value during execution of the coasting control based on the vehicle speed and the braking operation;

determine a fact that the deceleration demand is strong if the deceleration demand is larger than the predetermined value, and terminate the coasting control by bringing the clutch device into engagement to connect the power transmission route;

determine a probability that the deceleration demand is judged to be strong based on the vehicle speed and the braking operation; and

reduce a speed difference between a rotary member of the clutch device of the prime mover side and a rotary member of the clutch device of the drive wheel side prior to terminating the coasting control, by controlling a speed of the prime mover.

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

determine the fact that the deceleration demand is strong when the braking operation is continued longer than a first operate time under a condition that the vehicle speed is higher than a reference speed; and

determine the fact that the probability is high when the braking operation is continued longer than a second operate time that is shorter than the first operate time.

3. The vehicle control system as claimed in claim 2, wherein the controller is further configured to terminate the coasting control if the vehicle speed is lower than the reference speed when the braking operation is carried out.

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

determine the fact that the deceleration demand is strong when an amount of the braking operation is larger than a first operation amount under a condition that the vehicle speed is higher than a reference speed; and

determine the fact that the probability is high when the amount of the braking operation is larger than a second operation amount that is smaller than the first operation amount.

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

detect a road gradient; and

determine the fact that the deceleration demand is strong if a downgrade of a road on which the vehicle is running at a speed higher than a reference speed is steeper than a first gradient, and

determine the fact that the probability is high if the downgrade of the road on which the vehicle is running is steeper than a second gradient that is milder than the first gradient.

6. The vehicle control system as claimed in claim 5, wherein the controller is further configured to terminate the coasting control if the vehicle speed is lower than the reference speed when the braking operation is carried out.

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

detect an increasing amount of the vehicle speed; and

determine the fact that the deceleration demand is strong if an increasing amount of a speed of the vehicle running at a speed higher than a reference speed exceeds a first increasing amount, and

determine the fact that the probability is high if the increasing amount of the vehicle speed exceeds a second increasing amount that is smaller than the first increasing amount.

8. The vehicle control system as claimed in claim 7, wherein the controller is further configured to terminate the coasting control if the vehicle speed is lower than the reference speed when the braking operation is carried out.

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

detect a distance between the vehicle and a forerunning vehicle; and

determine the fact that the deceleration demand is strong if the distance of the vehicle running at a speed higher than a reference speed is reduced to be shorter than a first distance, and

determine the fact that the probability is high if the distance is reduced to be shorter than a second distance that is shorter than the first distance.

10. The vehicle control system as claimed in claim 1, wherein the controller further configured to terminate the coasting control if the vehicle speed is lower than a reference speed when the braking operation is carried out.