Zeroing algorithm of pointer instrument

Abstract

The invention relates to a zeroing algorithm of a pointer instrument. The zeroing algorithm concretely includes the zeroing steps that 1, it is assumed that a pointer is located at the position farthest from a zeroing mechanical limit during working of the instrument; 2, a stepping motor rotates rapidly by X degrees in the direction of the zeroing mechanical limit; 3, with a current position beinga hypothetical zero position, the stepping motor rotates clockwise from a farm end mechanical limit to the zeroing mechanical limit; 4, the stepping motor rotates multiples times in the direction ofthe zeroing mechanical limit, and rotation lasts for multiple milliseconds each time; 5, it is set that the stepping motor rotates clockwise from the zeroing mechanical limit to the far end mechanicallimit, and if the current position is set to be a scale zero position, zeroing is completed. Through the zeroing algorithm, whether the pointer of the instrument is located at one initial position oranother, the pointer can return to the same position rapidly and accurately, accordingly, the problem is solved that since the initial positions of the pointer are different, zeroing errors are generated, and it is guaranteed that the instrument can be normally used through one-time power-on zeroing under any condition. Through the algorithm, zeroing speed is high, uniformity is good, and errorsare small.

Description

technical field [0001] The invention relates to a pointer instrument driven by a stepping motor, in particular to an automobile pointer instrument using a special zero-returning algorithm. Background technique [0002] Stepper motors have the advantages of small size, low cost, and high reliability, and are very suitable for driving pointer instruments in automotive instruments. With the popularization of mass production of civilian vehicles, the technology and application of stepping motors are becoming more and more mature, and they have entered thousands of households unconsciously. [0003] However, the stepper motor itself cannot sense the rotational position and must be calibrated to zero before use. The accuracy of zero calibration directly determines the accuracy of the pointer instrument, thus affecting the use of the instrument. The stepper motor driver chip comes with zero-return and stop-return instructions. Due to its slow return to zero speed, in practical a...

AI Technical Summary

Problems solved by technology

And many algorithms will cause obvious pointer jitter

In addition, once the indicator does not stop near the zero position of the scale due to sudden power failure or other factors during use, when the power is turned on again, because the pointer is far away from the mechanical limit of zero return, the position where it stops after hitting a wall and rebounding, There is an imperceptible small deviation from the position where the initial position is near the zero position of the scale and bounces off the wall. This deviation will be greatly amplified by the next zero return and stop zero return commands, causing the pointer of the meter to deviate from the zero position of the scale. The error sometimes up to about 2°

Faced with this situation, it is generally necessary to turn off the power of the meter and turn it on again to let the stepper motor return to zero before returning to normal, which seriously affects the use of the pointer meter

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