Long-stroke position detection device and method

Abstract

The invention relates to a long-stroke position detection device and method. The detection device comprises a permanent magnet and a detection circuit board. The permanent magnet is fixedly arranged on a movable component at a position to be detected and does linear displacement along with the movable component; the detection circuit board detects the position of the permanent magnet in real time.The detection circuit board is a PCB comprising a magnetic sensor array, a multichannel gating module and a microprocessor module. By adopting the magnetic sensor array, the influence of magnetic field harmonic waves and external stray magnetic fields on the detection precision is avoided, meanwhile, errors caused by uneven air gaps can be reduced, and the magnetic sensor array has the advantageof high linearity. By adopting the multichannel gating module and the microprocessor module, only analog signals output by the magnetic sensor array close to or about to be close to the current to-be-detected position are subjected to signal gating, the number of channels of a synchronous analog-to-digital converter and the complexity of a conditioning circuit structure are reduced while the real-time performance of detection is ensured, and low power consumption is achieved.

Description

Technical field [0001] The present 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 has developed more maturely, 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., because their movable components are often passive, their position detection methods will be greatly restricted. Patent CN 109217767A aims at linear transmission system and proposes a linear displacement detection method based on grating or magnetic grating encoder, which places ...

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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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