CN-116490749-B - Rotation angle detection device

CN116490749BCN 116490749 BCN116490749 BCN 116490749BCN-116490749-B

Abstract

The rotation angle detection device includes a first detection unit (210), a second detection unit (230), and a calculation unit (250). The first detection unit detects a first rotation angle of a steering shaft (102) that rotates in conjunction with a steering wheel (101). A second detection unit detects a second rotation angle of a motor shaft (301) connected to the steering shaft via a reduction mechanism (302). The calculation unit inputs the first rotation angle from the first detection unit, inputs the second rotation angle from the second detection unit, and calculates the rudder angle of the steering shaft based on the difference angle between the first rotation angle and the second rotation angle.

Inventors

Niguchi Kako
TIAN ZHONGJIAN
UDA KEISUKE

Assignees

株式会社电装

Dates

Publication Date: 20260505
Application Date: 20211018
Priority Date: 20201116

Claims (6)

1. A rotation angle detection device, comprising: A first detection unit that detects a first rotation angle of a steering shaft that rotates in conjunction with a steering wheel; A second detection unit for detecting a second rotation angle of a motor shaft coupled to the steering shaft via a reduction mechanism, and A calculation unit that inputs the first rotation angle from the first detection unit and the second rotation angle from the second detection unit, calculates a rudder angle of the steering shaft based on a difference angle between the first rotation angle and the second rotation angle, The first detection unit includes: a driving gear that rotates in conjunction with the steering shaft; a driven gear engaged with the driving gear and rotated in conjunction with the driving gear; a magnet fixed to the driven gear and rotating together with the driven gear, and A magnetic flux detection unit that detects the first rotation angle of the steering shaft based on a change in magnetic flux received from the magnet, If the first reduction ratio of the reduction mechanism between the steering shaft and the motor shaft is defined as Z EPS , the second reduction ratio between the driving gear and the driven gear is defined as Z angle , the angle range of the rudder angle obtained by the arithmetic unit is defined as θ, The first reduction ratio Z EPS , the second reduction ratio Z angle and the angle range θ of the rudder angle are set to satisfy |(Z EPS -Z angle )×θ|<360° Or alternatively |(Z EPS -Z angle )×θ|<180° Is a condition of (2).
2. A rotation angle detection device, comprising: A first detection unit that detects a first rotation angle of a steering shaft that rotates in conjunction with a steering wheel; A second detection unit for detecting a second rotation angle of a motor shaft coupled to the steering shaft via a reduction mechanism, and A calculation unit that inputs the first rotation angle from the first detection unit and the second rotation angle from the second detection unit, calculates a rudder angle of the steering shaft based on a difference angle between the first rotation angle and the second rotation angle, The first detection unit includes: a driving gear that rotates in conjunction with the steering shaft; a driven gear engaged with the driving gear and rotated in conjunction with the driving gear; a magnet fixed to the driven gear and rotating together with the driven gear, and A magnetic flux detection unit that detects the first rotation angle of the steering shaft based on a change in magnetic flux received from the magnet, If the first reduction ratio of the reduction mechanism between the steering shaft and the motor shaft is defined as Z EPS , the second reduction ratio between the driving gear and the driven gear is defined as Z angle , the virtual gear ratio at which the second reduction ratio is an integer multiple is defined as N, the angle range of the rudder angle obtained by the arithmetic unit is defined as θ, The first reduction ratio Z EPS , the second reduction ratio Z angle , the virtual gear ratio N, and the angle range θ of the rudder angle are set so as to satisfy |(Z EPS -Z angle ×N)×θ|<360° Or alternatively |(Z EPS -Z angle ×N)×θ|<180° Is a condition of (2).
3. A rotation angle detection device, comprising: A first detection unit that detects a first rotation angle of a steering shaft that rotates in conjunction with a steering wheel; A second detection unit for detecting a second rotation angle of a motor shaft coupled to the steering shaft via a reduction mechanism, and A calculation unit that inputs the first rotation angle from the first detection unit and the second rotation angle from the second detection unit, calculates a rudder angle of the steering shaft based on a difference angle between the first rotation angle and the second rotation angle, The first detection unit includes: a driving gear that rotates in conjunction with the steering shaft; a driven gear engaged with the driving gear and rotated in conjunction with the driving gear; a magnet fixed to the driven gear and rotating together with the driven gear, and A magnetic flux detection unit that detects the first rotation angle of the steering shaft based on a change in magnetic flux received from the magnet, The magnet generates a change in magnetic flux of a plurality of cycles during one rotation of the driven gear, If the first reduction ratio of the reduction mechanism between the steering shaft and the motor shaft is defined as Z EPS , the second reduction ratio between the driving gear and the driven gear is defined as Z angle , the pole pair number of the magnet is defined as P angle , the angle range of the rudder angle obtained by the arithmetic unit is defined as θ, The first reduction ratio Z EPS , the second reduction ratio Z angle , the pole pair number P angle and the angle range θ of the rudder angle are set so as to satisfy |(Z EPS -Z angle ×P angle )×θ|<360° Or alternatively |(Z EPS -Z angle ×P angle )×θ|<180° Is a condition of (2).
4. A rotation angle detection device, comprising: A first detection unit that detects a first rotation angle of a steering shaft that rotates in conjunction with a steering wheel; A second detection unit for detecting a second rotation angle of a motor shaft coupled to the steering shaft via a reduction mechanism, and A calculation unit that inputs the first rotation angle from the first detection unit and the second rotation angle from the second detection unit, calculates a rudder angle of the steering shaft based on a difference angle between the first rotation angle and the second rotation angle, The first detection unit includes: a driving gear that rotates in conjunction with the steering shaft; a driven gear engaged with the driving gear and rotated in conjunction with the driving gear; a magnet fixed to the driven gear and rotating together with the driven gear, and A magnetic flux detection unit that detects the first rotation angle of the steering shaft based on a change in magnetic flux received from the magnet, The magnet generates a change in magnetic flux of a plurality of cycles during one rotation of the driven gear, If the first reduction ratio of the reduction mechanism between the steering shaft and the motor shaft is defined as Z EPS , the second reduction ratio between the driving gear and the driven gear is defined as Z angle , the pole pair number of the magnet is defined as P angle , the virtual gear ratio for making the second reduction ratio an integer multiple is defined as N, the angle range of the rudder angle obtained by the arithmetic unit is defined as θ, The first reduction ratio Z EPS , the second reduction ratio Z angle , the pole pair number P angle , the virtual gear ratio N, and the angle range θ of the rudder angle are set so as to satisfy |(Z EPS -Z angle ×P angle ×N)×θ|<360° Or alternatively |(Z EPS -Z angle ×P angle ×N)×θ|<180° Is a condition of (2).
5. The rotation angle detecting device according to any one of claims 1 to 4, wherein, The steering shaft has a torque sensor that detects a rotational torque of the steering shaft, The torque sensor has a magnet that rotates with the steering shaft.
6. The rotation angle detecting device according to any one of claims 1 to 4, wherein, The calculation unit includes an angle correction unit that multiplies an angle period of the first rotation angle by an integer.

Description

Rotation angle detection device Cross-reference to related applications The present application is based on Japanese patent application 2020-190049, filed on 11/16/2020, the contents of which are incorporated herein by reference. Technical Field The present invention relates to a rotation angle detection device. Background Conventionally, for example, patent document 1 proposes a steering angle detection device that detects a steering angle of a steering shaft of a vehicle. The rudder angle detection device is provided with a cursor (vernier) calculation unit, a neutral period determination unit, and a neutral point determination unit. The cursor calculation unit calculates a reference angle based on the motor angle and the steering shaft angle. The neutral period determination unit inputs the estimated or measured self-aligning torque (self-aligning torque) value. The neutral period determination unit determines a neutral period of the reference angle based on the self-returning torque value. The neutral point determination unit inputs a value of a reference angle of a handle neutral point stored in advance as a neutral point value. The neutral point determination unit inputs an angle signal that determines a neutral period including the neutral point, to the neutral period determination unit. The neutral point determination unit obtains a steering angle based on the neutral point value and the angle signal. Prior art literature Patent literature Patent document 1 International publication No. 2016/132878 Disclosure of Invention However, in the above-described conventional technique, a self-aligning torque value is required to obtain a steering angle. Therefore, the rudder angle detection device requires a complicated estimating means for estimating the self-aligning torque value and a measuring means for measuring the self-aligning torque value. The application provides a rotation angle detection device which can simplify rudder angle calculation without self-correcting torque value. According to one aspect of the present application, a rotation angle detection device includes a first detection unit, a second detection unit, and an arithmetic unit. The first detection unit detects a first rotation angle of a steering shaft that rotates in conjunction with a steering wheel. The second detection unit detects a second rotation angle of a motor shaft coupled to the steering shaft via a reduction mechanism. The calculation unit inputs the first rotation angle from the first detection unit, inputs the second rotation angle from the second detection unit, and calculates the rudder angle of the steering shaft based on the difference angle between the first rotation angle and the second rotation angle. This is a configuration in which the rudder angle of the steering shaft is calculated based on the difference between the first rotation angle of the steering shaft and the second rotation angle of the motor shaft. Therefore, the steering angle calculation of the steering shaft can be simplified without self-correcting the torque value. Drawings The above and other objects, features and advantages of the present application will become more apparent from the following detailed description with reference to the accompanying drawings. The drawings are as follows. Fig. 1 is a diagram showing a steering system according to a first embodiment. Fig. 2 is an exploded perspective view of the rudder angle sensor. Fig. 3 is a cross-sectional view showing the motor and the motor control device. Fig. 4 is a diagram showing the output of the rudder angle sensor and the output of the rotation angle sensor. Fig. 5 is a diagram showing a relationship between a rudder angle and a difference angle between a first rotation angle and a second rotation angle. Fig. 6 is a diagram showing the rudder angle in the case where the output of the rudder angle sensor is greatly different from the output of the rotation angle sensor in the second embodiment. Fig. 7 is a diagram showing a relationship between a rudder angle and a difference angle between the rotation angles shown in fig. 6. Fig. 8 is a perspective view of a magnet of the rudder angle sensor according to the second embodiment. Fig. 9 is a diagram showing an arithmetic unit according to the third embodiment. Fig. 10 is a diagram showing the output of the rudder angle sensor amplified 5 times. Fig. 11 is a flowchart showing the content of the angle correction processing by the arithmetic unit. Fig. 12 is a diagram showing an angle waveform that is an integer multiple of the angle correction processing. Fig. 13 is a diagram showing the relationship between the rudder angle detection range and the difference angle after enlargement. Fig. 14 is an exploded perspective view of the torque sensor of the third embodiment. Fig. 15 is a side view of a torque sensor of the third embodiment. Detailed Description Hereinafter, various embodiments for carrying out the present application will be d