Vehicle control apparatus and method

• US 20090043465A1
• Filed: 08/04/2008
• Published: 02/12/2009
• Est. Priority Date: 08/10/2007
• Status: Abandoned Application

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tomita, Makoto
• Application Number:
  US12/222,173
• Publication Number:
  US 20090043465A1
• Time in Patent Office: Days
• US Class Current: 701/51
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/30 Parking brake position
• CPC Class Codes: B60L 2240/642 Slope of road
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2510/186 Status of parking brakes
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 30/18118 Hill holding
• CPC Class Codes: F16H 63/483 Circuits for controlling engagement of parking locks or brakes
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

In a case where, in order to stop a hybrid vehicle on a hill, a brake device is turned on and then the shift lever is shifted to the parking position (“P” position) to lock a parking-lock device and then the brake device is turned off and then the brake device is turned on despite that torsional torque is acting on the drive shaft, a motor generator, which is an inertial object having a large weight, is driven to rotate in a rotational direction corresponding to the direction of gradient of the road, so that the resultant rotational torque is transmitted to a sun gear, to pinions, and to a ring gear.

Claims

1. A vehicle control apparatus, comprising:

a drive power input portion which is connected to a drive power source of the vehicle and to which drive power is input from the drive power source;

a drive power transmission portion that transmits drive power from the drive power input portion to a drive shaft via a gear mechanism so that drive wheels coupled with the drive shaft rotate;

a brake device that applies braking force corresponding to an operation amount of a brake pedal of the vehicle to the drive wheels;

a parking-lock device provided at the gear mechanism and adapted to be set in a lock position where gears of the gear mechanism are locked to lock the drive wheels when the gear mechanism is shifted to a first shift position and to be set in an unlock position where the gears of the gear mechanism are unlocked to allow the drive wheels to rotate when the gear mechanism is shifted to a second shift position;

a unit case containing the drive power input portion and the drive power transmission portion and supporting the gear mechanism;

an operation state detection portion that detects an operation state of the brake device;

a gradient detection portion that detects the gradient of a road on which the vehicle is presently located and detects the direction of the gradient of the road;

a rotational torque generation portion that generates rotational torque in a normal direction or in a reverse direction with respect to the rotational direction of the gears of the gear mechanism; and

a drive control portion that controls the rotational torque generation portion to generate rotational torque in a direction corresponding to the detected direction of the gradient of the road when the brake device is turned on while the gear mechanism is at the first shift position and the detected gradient of the road is equal to or larger than a predetermined gradient.

2. The vehicle control apparatus according to claim 1, wherein:

the rotational torque generation portion is constituted of a motor generator;

the gear mechanism is a planetary gearset having a sun gear, pinions provided around the sun gear, a carrier supporting the pinions and supported by the unit case, and a ring gear provided around the pinions and drivingly connected to the drive wheels;

a rotator shaft of the motor generator is coupled with the sun gear; and

the parking-lock device has a parking gear pole that is moved between a lock position where the parking gear pole is engaged with gear teeth at the outer periphery of the ring gear and an unlock position where the parking gear pole is disengaged from the gear teeth.

3. The vehicle control apparatus according to claim 1, wherein:

when the brake device is turned on while the gear mechanism is at the first shift position and the detected gradient of the road is equal to or larger than the predetermined gradient, the drive control portion controls the rotational torque generation portion to generate rotational torque in the same direction as the direction in which the gears of the gear mechanism rotate in response to the parking lock portion being switched from the lock position to the unlock position.

4. A vehicle control method for a vehicle having:

a drive power input portion which is connected to a drive power source of the vehicle and to which drive power is input from the drive power source;

a drive power transmission portion that transmits drive power from the drive power input portion to a drive shaft via a gear mechanism so that drive wheels coupled with the drive shaft rotate;

a brake device that applies braking force corresponding to an operation amount of a brake pedal of the vehicle to the drive wheels;

a parking-lock device provided at the gear mechanism and adapted to be set in a lock position where gears of the gear mechanism are locked to lock the drive wheels when the gear mechanism is shifted to a first shift position and to be set in an unlock position where the gears of the gear mechanism are unlocked to allow the drive wheels to rotate when the gear mechanism is shifted to a second shift position; and

a rotational torque generation portion that generates rotational torque in a normal direction or in a reverse direction with respect to the rotational direction of the gears of the gear mechanism, the vehicle control method comprising;

detecting an operation state of the brake device;

detecting the gradient of a road on which the vehicle is presently located and detecting the direction of the gradient of the road; and

controlling the rotational torque generation portion to generate rotational torque in a direction corresponding to the detected direction of the gradient of the road when the brake device is turned on while the gear mechanism is at the first shift position and the detected gradient of the road is equal to or larger than a predetermined gradient.