Torque control method and torque control device

Patent metadata

Field	Value
Publication number	US-10486546-B2
Application number	US-201616317181-A
Country	US
Kind code	B2
Filing date	Jul 15, 2016
Priority date	Jul 15, 2016
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A torque control method for controlling torque of a motor, comprises detecting request of speed control requested from a driver by using a sensor, calculating a request torque based on the request, performing, controlling torque generated at the motor based on the request torque, when the request torque is smaller than a predetermined torque threshold value, a coast traveling control for setting the request torque to zero and controlling the motor based on the request torque which is set to zero.

First claim

What is claimed is:

1. A torque control method for controlling torque of a motor, comprising:
detecting request of speed control requested from a driver by using a sensor;
calculating a request torque based on the request;
controlling torque generated at the motor based on the request torque; and
performing, when the request torque is smaller than a predetermined torque threshold value, a coast traveling control for setting the request torque to zero and controlling the motor based on the request torque which is set to zero,
wherein the predetermined torque threshold value when rotation speed of the motor is greater than a first rotation speed threshold value, is greater than the predetermined torque threshold value when the rotation speed of the motor is smaller than the first rotation speed threshold value.

2. The torque control method according to claim 1 , wherein
the predetermined torque threshold value is lower than torque required to maintain a constant vehicle speed.

3. The torque control method according to claim 1 , wherein
the predetermined torque threshold value is set to a constant value on the regeneration side.

4. The torque control method according to claim 1 , wherein
the coast traveling control is executed when the rotation speed of the motor is greater than a second rotation speed threshold value, and
the coast traveling control is not executed when the rotation speed of the motor is smaller than the second rotation speed threshold value.

5. The torque control method according to claim 1 , further comprising,
setting a torque change rate when the request torque is changed from a state in which the request torque is smaller than the predetermined torque threshold value to a state in which the request torque is greater than the predetermined torque threshold value, or the torque change rate when the request torque is changed from a state in which the request torque is greater than the predetermined torque threshold value to a state in which the request torque is smaller than the predetermined torque threshold value, according to the request torque.

6. The torque control method according to claim 1 , wherein
the coast traveling control is executed when a state in which the request torque is smaller than the predetermined torque threshold value is continued for a certain period of time or more.

7. The torque control method according to claim 1 , further comprising;
selecting a traveling mode of a vehicle including the motor from a plurality of traveling modes; and
selecting the predetermined torque threshold value from the plurality of the torque threshold values according to a selected traveling mode,
wherein the coast traveling control is executed when the request torque is smaller than the selected torque threshold value.

8. A torque control device, comprising:
an accelerator-opening sensor for detecting an accelerator opening;
a rotation speed sensor for detecting rotation speed of a motor;
a memory for storing a map indicating a relative relationship between torque of the motor, the rotation speed, and the accelerator opening; and
a controller for controlling the motor,
wherein, the controller
calculates the torque which corresponds to the accelerator opening and the rotation speed as a request torque from a driver while referencing the map,
controls the motor so that generation torque generated at the motor match with the request torque when the request torque is greater than a predetermined torque threshold value, and
controls the motor so that the generation torque becomes zero by setting the request torque to zero when the request torque is smaller than the predetermined torque threshold value, and
the predetermined torque threshold value when rotation speed of the motor is greater than a first rotation speed threshold value, is greater than the predetermined torque threshold value when the rotation speed of the motor is smaller than the first rotation speed threshold value.

Assignees

• Nissan Motor

Inventors

• Kurosawa Takahisa
• Nakamura Yohei

Classifications

• B60W30/18072

  Coasting · CPC title

• B60L50/60

  using power supplied by batteries (in combination with fuel cells B60L50/75) · CPC title

• B60L15/10 Primary

  for automatic control superimposed on human control to limit the acceleration of the vehicle, e.g. to prevent excessive motor current (electric devices for safety purposes B60L3/00) · CPC title

• B60L15/2045 Primary

  for optimising the use of energy · CPC title

• B60L2240/421

  Speed · CPC title