Motor output control system and method for hybrid vehicle

• US 6,717,378 B2
• Filed: 12/06/2002
• Issued: 04/06/2004
• Est. Priority Date: 12/12/2001
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Matsubara, Atsushi, Wakashiro, Teruo, Shinohara, Toshinari, Kitajima, Shinichi
• Primary Examiner(s): Masih, Karen
• Application Number:
  US10/310,947
• Publication Number:
  US 20030107335A1
• Time in Patent Office: 487 Days
• Field of Search: 318/445, 318/473, 318/34, 180/65.2, 701/43
• US Class Current: 318/34
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 2260/12 of combustion engines
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/918 Continuously variable

Abstract

A control system for preventing a sudden change in the passengers'"'"' feeling for the acceleration. After determining whether the assistance using the motor is permitted with respect to each of different control modes, an amount of assistance for each mode is calculated. If the output assistance is permitted in any mode, the maximum amount of assistance is selected, and a previous value of the maximum amount of assistance is compared with the current value of the maximum amount of assistance. A shift value is obtained by subtracting a predetermined assistance value from the previous value when the current value is less than the previous value, and the amount of assistance is set to the shift value until the shift value becomes equal to or less than the current value, so as to gradually shift the amount of assistance from the previous value to the current value.

Claims

1. A motor output control system built in a hybrid vehicle which comprises an internal combustion engine and a motor as driving sources and in which the output of the internal combustion engine is assisted using the motor according to the driving state of the vehicle, the system comprising:

an assistance mode determination section for determining whether the output assistance using the motor is permitted with respect to each of different control modes for the output assistance, where the determination is performed according to the driving state of the vehicle;

an amount of assistance calculating section for calculating an amount of output assistance for each of the different control modes;

an assistance permitting section for permitting the output assistance using the motor when the output assistance is permitted in any control mode according to the determination of the assistance mode determination section;

an amount of assistance selecting section for selecting the maximum amount of assistance among the amounts of assistance, which are calculated by the amount of assistance calculating section and are assigned to the different control modes, when the output assistance using the motor is permitted by the assistance permitting section; and

a mode shift section for;

comparing a previous value of the maximum amount of assistance, selected by the amount of assistance selecting section last time, with the current value of the maximum amount of assistance selected this time;

calculating a shift value obtained by subtracting a predetermined assistance value from the previous value when the current value is less than the previous value; and

setting the amount of assistance using the motor to the shift value until the shift value becomes equal to or less than the current value, so as to gradually shift the amount of assistance from the previous value to the current value.

2. A motor output control system as claimed in claim 1, wherein the assistance permitting section includes the assistance mode determination section.

3. A motor output control system as claimed in claim 1, wherein the control modes for the output assistance using the motor include at least:

a starting assistance mode for performing the output assistance when the vehicle is started;

a sudden acceleration assistance mode for performing the output assistance when the vehicle is suddenly accelerated;

a low load assistance mode for performing the output assistance when the load of the internal combustion engine is low; and

a high load assistance mode for performing the output assistance when the load of the internal combustion engine is high.

4. A motor output control method used for a hybrid vehicle which comprises an internal combustion engine and a motor as driving sources and in which the output of the internal combustion engine is assisted using the motor according to the driving state of the vehicle, the method comprising:

an assistance mode determination step of determining whether the output assistance using the motor is permitted with respect to each of different control modes for the output assistance, where the determination is performed according to the driving state of the vehicle;

an amount of assistance calculating step of calculating an amount of output assistance for each of the different control modes;

an assistance permitting step of permitting the output assistance using the motor when the output assistance is permitted in any control mode according to the determination in the assistance mode determination step;

an amount of assistance selecting step of selecting the maximum amount of assistance among the amounts of assistance, which are calculated in the amount of assistance calculating step and are assigned to the different control modes, when the output assistance using the motor is permitted in the assistance permitting step; and

a mode shift step of;

comparing a previous value of the maximum amount of assistance, selected in the amount of assistance selecting step last time, with the current value of the maximum amount of assistance selected this time;

calculating a shift value obtained by subtracting a predetermined assistance value from the previous value when the current value is less than the previous value; and

setting the amount of assistance using the motor to the shift value until the shift value becomes equal to or less than the current value, so as to gradually shift the amount of assistance from the previous value to the current value.

5. A motor output control method as claimed in claim 4, wherein the control modes for the output assistance using the motor include at least:

a starting assistance mode for performing the output assistance when the vehicle is started;

a sudden acceleration assistance mode for performing the output assistance when the vehicle is suddenly accelerated;

a low load assistance mode for performing the output assistance when the load of the internal combustion engine is low; and

a high load assistance mode for performing the output assistance when the load of the internal combustion engine is high.