Measuring method for corner of vehicle steering wheel

Abstract

The invention discloses a measurement method for the rotation angle of an automobile steering wheel. A main rotation body in the automobile steering wheel drives an auxiliary rotation body to rotate under the rotation driving of a transmission shaft; the transmission ratio of the main rotation body and the auxiliary rotation body is m:n; the main rotation body gains the relative rotation angle Theta1 of the main rotation body by a first rotation angle sensor; the auxiliary rotation body gains the relative rotation angle Thelta2 of the auxiliary rotation body by a second rotation angle sensor, thus gaining practical intercept K; theoretical intercept L is gained by the practical intercept K; the rotation ring number P of the main rotation body is then gained by the theoretical intercept L; the relative rotation angle Thelta1 of the main rotation body and the relative rotation angle Theta2 of the auxiliary rotation body are input into a micro-processor; after processing, the micro-processor outputs an absolute rotation angle Theta in m ring of the main rotation body, namely, the absolute rotation angle Theta in m ring of the main rotation body is gained by the rotation ring number P of the main rotation body and the relative rotation angle Theta1 of the main rotation body. The measurement method of the automobile steering wheel can eliminate the system error which is caused by idle course and realize precisely measuring the absolute rotation angle Theta in m ring in small volume and simple structure.

Description

technical field [0001] The invention relates to the field of sensors, in particular to a method for measuring the steering wheel angle of an automobile. Background technique [0002] The rotation angle sensor is used to detect the position of a rotation angle, and it can achieve high precision in measuring the rotation angle less than 360°. The high-precision photoelectric code disc can achieve more than 20 digits, that is, 1 second. If subdivision is used, a higher resolution can be achieved. However, when the measured angle range exceeds 360°, the problem of determining the number of turns will be encountered. Incremental angle sensors can measure multi-turn angles without reducing accuracy. However, incremental encoders have zero point accumulation. Error, poor anti-interference, power-off memory is required when the receiving device is shut down, zero or reference position should be reset when starting up, etc. Absolute angle measurement cannot be performed, and there a...

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Problems solved by technology

[0006] This patent is the closest to the present invention, but on the one hand, this technology obtains the multi-turn absolute rotation angle of the main rotation body by measuring the multi-turn rotation angle of the auxiliary rotation body and dividing it by the rotation ratio of the two wheels. On the other hand, this patent does not give a mathematical expression for the calculation of the number of gear rotations, but analyzes it by assuming specific parameters

[0007] The patent US6630823 of Matsushita Electric Industrial Co., Ltd. of Japan uses gear transmission to convert multi-turn rotation into linear motion to determine the number of turns, and measure the position of single-turn rotation at the same time to determine the absolute rotation angle of multi-turn. However, this device has parts that move up and down. On the one hand, there is a problem of long-term wear and tear that leads to reduced accuracy or even slippage. On the other hand, the device is long in the longitudinal direction, which does not meet the flat requirements of the steering wheel angle sensor of the car. Moreover, the device has many transmission bodies, which is not conducive to long-term Stability of use

[0008] In these prior art inventions, it is impossible to eliminate the error caused by lost motion under the condition of smaller volume and as few transmission mechanisms as possible to accurately measure the absolute rotation angle of multiple turns

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