Rotating shaft angle and speed measuring device

Abstract

The invention provides a rotating shaft angle and speed measuring device to improve the measuring precision of an existing rotating shaft angle and speed measuring device. The structure of the devicecomprises a permanent magnet, a chip integrated with a magnetoresistive sensor, and a PCB circuit board. A number of chips are arranged on the upper end face of the PCB circuit board. A number of counter bores are arranged in the lower end face of the PCB circuit board. The axis of each counter bore passes through the centroid of a chip. The permanent magnet and the PCB circuit board are firmly connected through the counter bores. The magnetoresistive sensor is provided with a first power supply connection end, a grounding end, a first signal output end and a second signal output end. The first signal output end is connected in series with a first resistor and is electrically connected with a second power supply connection end. The first signal output end is connected in series with a second resistor and is grounded. The second signal output end is connected in series with a third resistor and is electrically connected with the second power supply connection end. The second signal output end is connected in series with a fourth resistor and is grounded. According to the invention, the connection relationship between the permanent magnet and the PCB circuit board is improved, and the detection sensitivity is greatly improved.

Description

technical field [0001] The invention relates to the technical field of measuring equipment for rotating shaft motion parameters, in particular to a measuring device for rotating shaft angle and speed. Background technique [0002] The measurement of the angle and speed of the rotating mechanism (machine tool, engine, etc.) plays a key role in its subsequent control system. The photoelectric encoder itself has high precision and non-contact characteristics and has been widely used. However, due to the poor adaptability of photoelectric encoders to harsh environments, magnetic rotary encoders have been developed in recent years. Such as figure 1 As shown, the magnetic rotary encoder in the prior art is generally composed of a magnetoresistive sensor (tunneling magnetoresistance, giant magnetoresistance and other principles, usually 2 to 3 bridges composed of 4-12 resistors are packaged into an integrated circuit chip), positive / cosine signal interpolation, self-correction ...

AI Technical Summary

Problems solved by technology

Due to the slight difference in the installation position of the permanent magnet in the rotating shaft angle and speed measuring device based on the above structure in the prior art, the sensing sensitivity of the chip integrated with multiple magnetoresistive sensors after assembly is uneven, and some products even There is a technical problem of low detection accuracy

[0004] In addition, since the output signal strength of the magnetoresistive sensor in the magnetic rotary encoder will weaken as the input rotation speed increases, when the input speed increases to a certain value (such as 20000r / min), the signal weakens to the point that it cannot satisfy the sine / cosine signal interpolation , Self-calibration driver (hereinafter referred to as the driver) input signal strength requirements

In order to increase the signal strength, the method of increasing the power supply voltage of the magnetoresistive sensor is adopted. When the gear to be tested is rotating or stationary, it will cause figure 1 The values ​​of the offset voltages V1 and V2 of the two outputs of each bridge (such as the sinusoidal positive (SIN+) and sinusoidal negative (SIN-) of the sinusoidal output) exceed the allowable input range of the driver, resulting in the failure of the entire system to output the correct Speed ​​and angle signals, cosine (COS+ and COS-) output and zero output (ZERO+ and ZERO-) are similar

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