Vehicle control system

• US 9,522,672 B2
• Filed: 02/05/2015
• Issued: 12/20/2016
• Est. Priority Date: 02/06/2014
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Okamoto, Tsuyoshi
• Primary Examiner(s): Cheung, Calvin
• Assistant Examiner(s): SCHNEIDER, PAULA LYNN
• Application Number:
  US14/614,954
• Publication Number:
  US 20150217757A1
• Time in Patent Office: 684 Days
• Field of Search: 701/22
• 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 configured to produce a driving force for the hybrid vehicle, wherein the hybrid vehicle runs at least with the driving force of the engine in a non-electric-vehicle running mode;

a motor-generator configured to generate electric power when the motor-generator is driven to rotate by the engine, wherein the hybrid vehicle runs only with the electric power of the motor-generator in an electric-vehicle running mode;

an electric-power charging device connected to the motor-generator configured to charged the electric power generated at the motor-generator and configured to supply 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 processor for executing a control program, the control device being at least configured to;

obtain information of cooling water temperature, which is temperature of cooling water for the engine;

obtain information of a charging state of the electric-power charging device; and

calculate an engine operating point including engine rotational speed and engine torque,

wherein the engine operates 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, during a period in which the hybrid vehicle runs in the non-electric-vehicle running mode,

in the first operating mode, the engine rotational speed and engine torque are calculated 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 engine operates 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, during the period in which the hybrid vehicle runs in the non-electric-vehicle running mode, and

in the second operating mode, the engine rotational speed and engine torque, which realize such engine operation according to which minimum electric power is generated by the motor-generator, are calculated, 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 configured to produce a driving force for the hybrid vehicle, wherein the hybrid vehicle runs at least with the driving force of the engine in a non-electric-vehicle running mode;

a motor-generator configured to generate electric power when the motor-generator is driven to rotate by the engine, wherein the hybrid vehicle runs only with the electric power of the motor-generator in an electric-vehicle running mode;

an electric-power charging device connected to the motor-generator Configured to charge the electric power generated at the motor-generator and configured to supply 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 processor for executing a control program, the control device being at least configured to;

obtain information of cooling water temperature, which is temperature of cooling water for the engine;

obtain a charging state of the electric-power charging device; and

calculate 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, during a period in which the hybrid vehicle runs in the non-electric-vehicle running mode,

wherein the engine operating point includes engine rotational speed and engine torque.

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

the engine rotational speed and the engine torque are calculated, 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 charging state of the electric-power charging device is predicted at a timing when the cooling water temperature reaches the target temperature value, and

the target charging-state value is set based on a predicted charging-state value of the electric-power charging device.