A long-stroke position detection device and method

Abstract

The invention relates to a long-stroke position detection device and method. The detection device includes a permanent magnet and a detection circuit board; the permanent magnet is fixedly installed on a movable component at a position to be detected, and linearly displaces with the movable component; the detection circuit board detects the position of the permanent magnet in real time. Wherein, the detection circuit board is a PCB board including a magnetic sensor array, a multiplex gate module and a microprocessor module. By adopting the magnetic sensor array, the present invention can reduce the error caused by uneven air gap while avoiding the influence of the magnetic field harmonic and the external stray magnetic field on the detection accuracy, and has the advantage of high linearity. By using the multi-channel gating module and the microprocessor module, only the analog signal output by the magnetic sensor array that is close to or about to be close to the current position to be measured is gated, and the synchronous analog-to-digital converter is reduced while ensuring the real-time detection The number of channels and the complexity of the conditioning circuit structure, and achieve low power consumption.

Description

technical field [0001] The invention relates to the field of long-stroke position detection, in particular to a long-stroke position detection device and method. Background technique [0002] In the field of industrial control, it is often necessary to accurately detect the position of movable components in a non-contact manner for closed-loop feedback of the system. In short-stroke position detection, this technology is relatively mature, and detection components such as grating scales and magnetic scales have been widely used. However, in the field of long-stroke motion control, such as electromagnetic ejection devices, linear transmission devices based on segmented linear motors, etc., since their movable components are often passive, their position detection methods will be greatly limited. Patent CN 109217767A proposes a linear displacement detection method based on a grating or magnetic grating encoder for a linear transmission system. The scale is placed on the mover...

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Problems solved by technology

However, the Hall device is sensitive to unsaturated magnetic fields, and there must be harmonic components in the magnetic field of the magnet. It is also difficult to ensure a uniform air gap between the magnet and the device, and the superposition of the external stray magnetic field affects the detection accuracy of this method.

Patent CN 101915590 B proposes a magnetoresistive array-based position detection system, which obtains the position of the movable member by signal processing of the unequal-distance magnetoresistive sensing components, but this method is not suitable for long-stroke detection because each The magnetoresistive components need to be associated with the corresponding integrated circuits in multiple chip carriers, and a large number of analog signal conditioning and ADC converter channels are required under long strokes, resulting in circuits that are too complex and costly to be practically applied

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