Shift-by-wire controller

Patent metadata

Field	Value
Publication number	US-9416868-B2
Application number	US-201414317235-A
Country	US
Kind code	B2
Filing date	Jun 27, 2014
Priority date	Jun 28, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A shift-by-wire controller is applied to a shift-by-wire system which switches a shift range of an automatic transmission by a driving force of a motor, and drives the motor according to an input signal. The shift-by-wire controller includes a position sensor, a position acquirement portion acquiring a switching edge corresponding to a position where the shift range is switched from the position sensor, an encoder detecting a rotational position of the motor, a determining portion determining whether the rotational position can be acquired as a present-position from the encoder, and a position determination portion. When the determining portion determines that the present-position cannot be acquired, the position determination portion drives the motor to switch the shift range, and determines a position of the motor based on the switching edge.

First claim

What is claimed is:

1. A shift-by-wire controller for a shift-by-wire system which switches a shift range of an automatic transmission by a driving force of a motor, the shift-by-wire controller driving the motor according to an input signal, the shift-by-wire controller comprising:
a position sensor detecting whether the automatic transmission is placed at one of a plurality of the shift ranges;
a position acquirement portion acquiring a switching edge corresponding to a position where the shift range is switched, from the position sensor, every time that the shift range is switched;
an encoder detecting a rotational position of the motor;
a determining portion determining whether the rotational position can be acquired from the encoder as a present-position;
a position determination portion driving the motor to switch the shift range, and determining a position of the motor based on the switching edge acquired by the position acquirement portion while the shift range is switch, when the determining portion determines that the present-position cannot be acquired and the position sensor detects the shift range;
a storage portion storing driving amounts between the shift ranges acquired by the position acquirement portion as shift learning values, every time that the shift range is switched; and
a driving control portion driving the motor to switch the shift range to a target shift range corresponding to the input signal, based on the position of the motor determined by the position determination portion and the shift learning values stored in the storage portion.

2. The shift-by-wire controller according to claim 1 , further comprising:
the driving control portion (i) calculates a target position of the motor corresponding to the target shift range as a calculated target position, based on the position of the motor determined by the position determination portion and the shift learning values stored in the storage portion, and (ii) corrects the driving amount corresponding to an amount necessary to switch the shift range to the calculated target position, based on an edge learning value corresponding to a learning value of the switching edge stored in the storage portion.

3. The shift-by-wire controller according to claim 1 , further comprising:
an initial-position learning portion learning an initial position of the motor, when the shift range is placed at a specified shift range, wherein
the driving control portion drives the motor without learning the initial position by the initial-position learning portion, when the determining portion determines that the present-position can be acquired.

4. The shift-by-wire controller according to claim 1 , further comprising:
an input portion receiving an input of the shift range as a required shift range; and
an estimating portion estimating the position of the shift range, based on the required shift range received by the input portion, a signal indicating the shift range detected by the position sensor in a normal state, and the switching edge in the normal state, wherein
the driving control portion drives the motor from the position estimated by the estimating portion to the target shift range, when the determining portion determines that the present-position cannot be acquired.

5. The shift-by-wire controller according to claim 1 , wherein
the driving control portion drives the motor and switches the automatic transmission to an end shift range disposed at an end portion among the shift ranges, when the position sensor cannot determine the shift range, and
the position acquirement portion detects the switching edge by a switch of the shift range.

6. The shift-by-wire controller according to claim 5 , wherein
the shift ranges include a P-range and a D-range which are disposed at two end portions, respectively, and an R-range and an N-range which are disposed between the P-range and the D-range from the P-range in the order of the R-range and the N-range, wherein the P-range is for parking, the D-range is for driving, the R-range is for reversing, and the N-range is for making the automatic transmission neutral, and
the driving control portion drives the motor toward the P-range and detects the switching edge, when a request for switching the shift range to the P-range is generated.

7. A shift-by-wire controller for a shift-by-wire system which switches a shift range of an automatic transmission by a driving force of a motor, the shift-by-wire controller driving the motor according to an input signal, the shift-by-wire controller comprising:
a position sensor detecting whether the automatic transmission is placed at one of a plurality of the shift ranges;
a position acquirement portion acquiring a switching edge corresponding to a position where the shift range is switched, from the position sensor, every time that the shift range is switched;
an encoder detecting a rotational position of the motor;
a determining portion determining whether the rotational position can be acquired from the encoder as a present-position;
a position determination portion driving the motor to switch the shift range, and determining a position of the motor based on the switching edge acquired by the position acquirement portion while the shift range is switched, when the determining portion determines that the present-position cannot be acquired and the position sensor detects the shift range;
an input portion receiving an input of the shift range as a required shift range; and
an estimating portion estimating the position of the shift range, based on the required shift range received by the input portion, a signal indicating the shift range detected by the position sensor in a normal state, and the switching edge in the normal state, wherein
the driving control portion drives the motor from the position estimated by the estimating portion to the target shift range, when the determining portion determines that the present-position cannot be acquired.

Assignees

• Denso Corp

Inventors

• Yatou Yoshihiro
• Shimizu Kenji

Classifications

• Y10T74/2003

  Electrical actuator · CPC title

• F16H59/105 Primary

  consisting of electrical switches or sensors · CPC title

• F16H2061/326

  Actuators for range selection, i.e. actuators for controlling the range selector or the manual range valve in the transmission · CPC title