VEHICLE CONTROL SYSTEM

• US 20150217757A1
• Filed: 02/05/2015
• Published: 08/06/2015
• Est. Priority Date: 02/06/2014
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: OKAMOTO, Tsuyoshi
• Granted Patent: US 9,522,672 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: F02D 2200/021 Engine temperature
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

A hybrid control device calculates engine rotational speed and engine torque based on cooling water temperature for an engine and a charging state of a main battery. The hybrid control device operates the engine in a maximum charging efficiency mode, when the cooling water temperature is lower than a target temperature value and the main battery has a remaining charging capacity. In the maximum charging efficiency mode, the hybrid control device calculates such engine rotational speed and engine torque, which realize engine operation according to which a fuel consumption amount for a unit amount of charging electric power is minimized. As a result, efficiency of a vehicle control system is improved as a whole, to thereby improve fuel consumption ratio.

Claims

1. A vehicle control system for a hybrid vehicle comprising:

an engine for producing a driving force for the hybrid vehicle;

a motor-generator for generating electric power when the motor-generator is driven to rotate by the engine;

an electric-power charging device connected to the motor-generator for charging the electric power generated at the motor-generator and for supplying the electric power to an electric load of an accessory device mounted to the hybrid vehicle; and

a control device for controlling an operation of the engine, wherein the control device includes;

a first portion for obtaining information of cooling water temperature, which is temperature of cooling water for the engine;

a second portion for obtaining information of a charging state of the electric-power charging device; and

a third portion for calculating an engine operating point including engine rotational speed and engine torque,

wherein the third portion operates the engine in a first operating mode when the cooling water temperature is lower than a predetermined temperature and the charging state of the electric-power charging device has a remaining charging capacity,

in the first operating mode, the third portion calculates such engine rotational speed and engine torque based on the charging state of the electric-power charging device, which realize such engine operation according to which a fuel consumption amount for a unit amount of electric power to be charged into the electric-power charging device is minimized,

the third portion operates the engine in a second operating mode when the cooling water temperature is lower than the predetermined temperature and the charging state of the electric-power charging device has no remaining charging capacity, and

in the second operating mode, the third portion calculates such engine rotational speed and engine torque, which realize such engine operation according to which minimum electric power is generated by the motor-generator, wherein the minimum electric power satisfies at least electric power to be consumed by the electric load of the accessory device mounted to the hybrid vehicle.

2. A vehicle control system for a hybrid vehicle comprising:

an engine for producing a driving force for the hybrid vehicle;

a motor-generator for generating electric power when the motor-generator is driven to rotate by the engine;

an electric-power charging device connected to the motor-generator for charging the electric power generated at the motor-generator and for supplying the electric power to an electric load of an accessory device mounted to the hybrid vehicle; and

a control device for controlling an operation of the engine, wherein the control device includes;

a first portion for obtaining information of cooling water temperature, which is temperature of cooling water for the engine;

a second portion for obtaining information of a charging state of the electric-power charging device; and

a third portion for calculating an engine operating point based on a current cooling water temperature, a target temperature value for the cooling water temperature, a current charging-state value of the electric-power charging device and a target charging-state value for the charging state of the electric-power charging device, wherein the engine operating point includes engine rotational speed and engine torque.

3. The vehicle control system according to claim 2, wherein

the third portion calculates the engine rotational speed and the engine torque, based on not only a temperature difference between the current cooling water temperature and the target temperature value but also a charging-state difference between the current charging state and the target charging-state value.

4. The vehicle control system according to claim 2, wherein

the third portion predicts the charging state of the electric-power charging device at a timing when the cooling water temperature reaches the target temperature value, and

the third portion sets the target charging-state value based on a predicted charging-state value of the electric-power charging device.