Method and device for identifying liquid state in pan in vibration test mode

Abstract

The invention relates to a method and a device for identifying a liquid state in a pan in a vibration test mode. A measuring rod or a table board, a vibration sensor and an A / D sampling analysis circuit module are included. The measuring rod or the table board is rigidly contacted with the pan. The vibration sensor and the measuring rod or the table board are tightly contacted. The A / D sampling analysis circuit module is connected to the vibration sensor through a shielded wire. In the method, principles that the pan is heated unevenly and an internal liquid generates vibration because of convection heat transfer movement and bubble breakage are used so that the vibration signal of the pan is transmitted to the vibration sensor and then is converted into an electric signal. After signal conditioning, the A / D sampling analysis circuit module carries out time domain / frequency domain conversion so as to generate a amplitude frequency characteristic value and a power spectrum value. An operation combination is taken as a determination basis value. Through comparing a background value when there is no liquid in the pan with an actual value, static state determination is performed, or according to the change trends of the values, the liquid state in the pan is determined, wherein the liquid state includes whether there is the liquid in the pan, a convection degree, boiling or not ora specific intermediate state.

Description

technical field [0001] The invention relates to a liquid state detection technology in a pot, in particular to a vibration-measuring method and device for identifying the convective state of liquid in a pot, which are suitable for stoves Background technique [0002] At present, there is no method and device for the whole process of monitoring and judging whether there is liquid in the pot placed on it, the convection state and boiling state of the liquid after the liquid is heated, which will easily lead to empty burning / drying, overflow after boiling and For problems such as excessive boiling, refer to related technologies and patents, there are the following types of technical solutions for detecting dry burning and boiling: [0003] 1. Judgment of dry burning: Measure the temperature of the bottom of the pot through the temperature sensor attached to the bottom of the pot. If it exceeds the set value, it is considered dry burning. This technology can only judge whether ...

AI Technical Summary

Problems solved by technology

[0005] A. Measure the vibration characteristics produced by the liquid vaporization process during boiling. For example, the Chinese patent No. 200620025739.0 "Water Boiling Detection Device for Electromagnetic Cooker" uses the mechanical vibration generated by the vaporization of water droplets when water boils to identify, and can only identify single boiling state;

[0006] B. Judgment by measuring the audio characteristics when boiling, such as the publication numbers 201010607284.2 and 201020682133.9 Chinese patent "A Water Boiling Detection Device for Induction Cooker", which only judges the boiling characteristics in the audio domain, and cannot judge whether there is liquid, the degree of convection, and empty heating / burn dry and other features;

[0007] C. Measuring the infrared radiation of the pot, judging that the surface temperature of the pot and the infrared radiation value will not exceed a certain range when there is water in the pot. For example, the Chinese patent "Induction Heating Cooker" with patent number 201110398864.X discloses infrared sensor detection Boiling technology only recognizes a single state, and has certain restrictions on the scope of application of the pot

[0008] All the above technical solutions are only for a certain project, and have certain scope of application and limitations, such as not being able to identify dry boiling and boiling at the same time, whether there is water / oil in the pot, and whether the water / oil is boiling, etc., and not being able to identify the liquid in the pot degree of convection or boiling etc.

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